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CONTENTS

Acknowledgements

viii

Case

Deteriorating shortness of breath in a smoker

Case

The breathless asthmatic

Case

An icy fall

Case

Difficulty swallowing

Case

A mechanical fall in an elderly patient

Case

Right upper abdominal pain

Case

Heartburn, epigastric pain and a cough

Case

Lines, catheters and tubes on a radiograph

Case

Weakness and slurring while out for a drink

Case

10 Back pain relieved only by aspirin

Case

11 A persistent cough in an ex-smoker

Case

12 A schoolmaster with progressive breathlessness

Case

13 Numb right arm

Case

14 Jaundice following cholecystectomy

Case

15 Infant with clicking hips

Case

16 Painful wrist after falling

Case

17 Constipation in woman with ovarian tumour

Case

18 Thirty-year-old man with headache

Case

19 Persistent cough

Case

20 Chest pain and dyspnoea

Case

21 Young man with neck swelling

Case

22 Collapse and possible seizure

Case

23 Premature neonate with abdominal distension

Case

24 Young child with painful arm

Case

25 Acute epigastric pain

Case

26 Man with atypical chest pain

Case

27 Young woman with shortness of breath and chest pain

Case

28 Chest discomfort and dyspnoea

Case

29 Skateboarder with a painful foot

Case

30 Left-sided loin pain

Case

31 Unable to bear weight after a cycling accident

Case

32 Strange bone appearance after falling

Case

33 Lower back pain

103

Case

34 Vomiting baby boy

105

Case

35 Painless haematuria

107

Case

36 Sudden onset weakness in an 80-year-old woman

109

Case

37 Young man with ankle pain

111

Case

38 Painful shoulder

113

Case

39 Chest pain after falling

117

Case

40 Swelling of the big toe

119

Case

41 A young man with progressive dyspnoea on exertion

121

100 Cases in Radiology

Case

42 Pain on deep inspiration

123

Case

43 An elbow injury

127

Case

44 Pain in the hand following a punching injury

129

Case

45 A fall on the hand and pain in the wrist

131

Case

46 Shortness of breath and pleuritic chest pain

133

Case

47 A new arrival with cough and a fever

135

Case

48 A seatbelt injury

137

Case

49 A device in the pelvis

139

Case

50 A cardiac abnormality

141

Case

51 A mirror image

143

Case

52 A distended and painful abdomen

145

Case

53 Bloody sputum and weight loss

147

Case

54 A soft fluctuant lump

149

Case

55 Abdominal distension and shifting dullness

151

Case

56 A painful hand

153

Case

57 A retired construction worker with a cough

155

Case

58 Distended abdomen and unable to pass gas

157

Case

59 Torrential haematemesis

159

Case

60 An incidental finding on chest radiograph

161

Case

61 A worried nurse in intensive care

163

Case

62 Young man with abdominal pain

165

Case

63 Skin plaques and achy hands

167

Case

64 Teaching sport can be a headache at times

171

Case

65 A chesty infant

173

Case

66 Difficulty in swallowing

175

Case

67 Pregnant woman with vomiting

177

Case

68 Infant with a head injury

181

Case

69 Abdominal distension in a woman with ovarian cancer

187

Case

70 A woman with a breast lump

190

Case

71 A rising creatinine

193

Case

72 Neck pain after falling

197

Case

73 A young man with back pain

200

Case

74 A child with an injury

205

Case

75 A renal tract abnormality

209

Case

76 Shooting leg pain following lifting

213

Case

77 A chronic productive cough

215

Case

78 General fatigue and weakness

219

Case

79 A cervical spine injury following a horse riding accident

221

Case

80 Abdominal pain and diarrhoea in a 28-year-old woman

225

Case

81 Pain in the left wrist following a fall

229

Case

82 A known case of inflammatory bowel disease

233

Case

83 A tourist from New Zealand

237

Case

84 Spontaneous nose bleeds in a young person

241

Case

85 Abdominal weight gain and distension despite dieting

245

Case

86 Left mid zone crackles

249

Case

87 Traumatic injury to a farmer’s foot

253

Case

88 An accountant with abdominal pain

257

Case

89 Pain in a woman with breast cancer

261

Case

90 Headache and visual field defects

265

Case

91 A claudicant with worsening leg pain

269

Case

92 Normal variant on a chest radiograph

273

CASE 1: DETERIORATING SHORTNESS OF BREATH IN A SMOKER

History

You are asked to review a 72-year-old man on the post-take ward round. He was admit-

ted last night with increasing shortness of breath. His breathing has been getting worse

for many years now, and he notices that it is especially bad in the winter. His general

practitioner (GP) has diagnosed asthma and has been managing him at home. He recalls

having several courses of antibiotics over the last few years.

His recent problems started 3 days ago with a cough productive of green sputum. He has

felt generally unwell and his breathing has deteriorated significantly. He cannot climb

the stairs at home now and slept on the sofa last night. His GP saw him this morning and

referred him to hospital as an infective exacerbation of asthma. He continues to smoke

despite advice, and has a 50 pack-year history. There is no other relevant past medical

history. He takes a salbutamol inhaler when needed but today this was of little help.

Examination

Some blood tests were performed and a chest radiograph was requested (Figure 1.1). His

white cell count is 16.3 × 10⁹/L, neutrophil count 89 per cent and haemoglobin 14.2 g/dL.

Figure 1.1 Chest radiograph.

Questions

• What does this radiograph show?

• What is the likely diagnosis and how can this be confirmed?

ANSWER 1

This is a posterior-anterior (PA) chest radiograph of an adult male. The lungs are hyper-

expanded as evidenced by visualizing more than six anterior ribs above the diaphragm.

The distance between the apex of the hemidiaphragm and a line drawn from the costo-

phrenic to the cardiophrenic angle is less than 1.5 cm, in keeping with diaphragmatic

flattening. The lung parenchyma demonstrates bullous emphysematous disease, most

marked in the upper zones. There is no evidence of consolidation, collapse or pneumo-

thorax. The cardiomediastinal borders are within normal limits, and both hila are of

normal morphology. This chest radiograph suggests a diagnosis of chronic obstructive

pulmonary disease (COPD).

COPD is a combination of increased mucus production, small airway obstruction and

emphysematous change, with a slow and progressive history of increasing shortness

of breath, usually in association with significant tobacco usage. Most commonly, the

emphysematous component is ‘centrilobular’, with irreversible destruction of normal lung

most in the apical segments of the upper lobes. On computed tomography (CT) this is

clearly seen as central black holes of destroyed lung ‘punched-out’ from normal paren-

chymal architecture (Figure 1.2), although a CT is not a necessary investigation in most

cases of COPD. Sometimes the clinical symptoms of COPD are confused with asthma,

which usually starts in childhood and shows greater reversibility of airflow obstruction.

Some patients develop asthma later in life, and in practice both conditions may coexist

or be difficult to differentiate.

The most important investigation in a

patient with COPD is lung function test-

ing. Spirometry shows the reduced forced

expiratory volume in 1 second : forced

vital capacity (FEV₁ : FVC) ratio charac-

teristic of obstructive conditions. There is

an increase in the total lung capacity (TLC)

and residual volume (RV) in COPD as a

result of air trapping.

Reversibility to bronchodilators is limited

in COPD. Assessment of functional capac-

ity is an important part of the evaluation

in chronic COPD. In acute exacerbations

such as that described, it is important to

assess blood gases to look for significant

Figure 1.2 CT scan.

hypoxia and/or carbon dioxide retention.

KEY POINTS

• Flattening of the diaphragms and lung hyperexpansion are characteristic chest

radiograph features of COPD.

• COPD is a combination of increased mucus production, small airways obstruction and

emphysematous change.

• Lung function tests are the most important investigation in a patient with COPD.

CASE 2: THE BREATHLESS ASTHMATIC

History

A 36-year-old woman presented to the accident and emergency department complaining

of progressively increasing breathlessness over the last 2 weeks. This was accompanied by

a wheeze and cough productive of white sputum. Her exercise tolerance had reduced and

she denied any orthopnoea or chest pain. She had a history of asthma which was usually

well controlled with inhalers and had never previously required a hospital attendance.

There was no other history of note and she denied ever being a smoker. She lived at home

with her husband and two children.

Examination

On examination, her respiratory rate was 22 breaths per minute. She was afebrile and

normotensive with a regular pulse rate of 88 per minute. Her cardiovascular and abdomi-

nal examinations were normal, but on auscultation of her lungs there was a prolonged

expiratory wheeze with reduced air entry at the left base.

A chest radiograph was performed as part of her initial investigations (Figure 2.1).

Figure 2.1 PA chest radiograph.

Questions

• What radiological abnormality is present?

• What is the most likely cause considering her history?

ANSWER 2

This patient has left lower lobe collapse. Depending on the airway obstructed, each lobe

collapses in a characteristic way. This was originally described by Benjamin Felson, a

professor of radiology in the United States in 1973. In the case of the left lower lobe,

when there is proximal occlusion, the lobe collapses posteriorly and medially towards the

spine. Lying behind the heart, it assumes a triangular shape with a straight lateral border

being classically described as a ‘sail sign’ on posterior-anterior (PA) chest radiograph as

shown in Figure 2.2.

It usually overlies the cardiac shadow and

can be easily missed on poorly windowed or

under-penetrated films. The collapsed lobe

obscures the left medial hemidiaphragm

and the horizontal fissure swings down-

wards with the hilar displaced inferiorly.

Other features to help confirm the diagnosis

would include mediastinal and tracheal

shift towards the side of the collapse, and

possible herniation of the contralateral

lung across the midline from compensatory

hyperinflation. The degree of hilar depres-

sion and compensatory hyperaeration is

variable depending on the degree of col-

lapse. Less commonly, a stenosing broncho-

Figure 2.2 PA chest radiograph with ‘sail sign’

genic tumour may be seen as a soft tissue

indicated.

density overlying the left hilar point.

The causes of lobar collapse are numerous; incidence varies with age and clinical history.

Overall, the commonest cause of collapse is related to a proximal stenosing bronchogenic

carcinoma, and although the majority of lung cancer is seen in men, the incidence in

women is rising. Lung cancer is rarely diagnosed in people younger than 40, but the

incidence rises steeply thereafter with most cases (85 per cent) occurring in people over

the age of 60 with a past medical history of smoking. In ventilated patients, including

neonates, malpositioning of the endotracheal tube can aerate one lung and occlude the

contralateral side, while in infants, collapse related to an inhaled foreign body (e.g. a

peanut) should always be considered. In older children and young adults, the commonest

cause of lobar collapse is as a complication of asthma.

Asthma is a chronic inflammatory disease characterized by reversible airflow limitation

and airway hyperresponsiveness. In response to immunological stimuli, mucus hyper-

secretion from goblet cell hyperplasia can cause airway plugging. Proximal occlusion of

a bronchus causes loss of aeration, and as the residual air is gradually absorbed, the lung

volume reduces with eventual collapse. Considering the patient’s age and clinical history,

this is the most likely cause of her left lower lobe collapse.

KEY POINTS

• Depending on the airway affected, each lobe collapses in a characteristic way.

• The ‘sail sign’ on a PA chest radiograph is indicative of left lower lobe collapse.

• In paediatric cases, always consider inhaled foreign body as a possible cause of lobar

collapse.

CASE 3: AN ICY FALL

History

A 39-year-old woman is sent for an X-ray following a fall. She slipped on some ice while

out shopping and raised her right hand to break the fall but her little finger was hyper-

flexed in the palm of her hand. She felt an instant sharp and stabbing pain in her little

finger, which was centred over the distal and interphalangeal joints. Over the next few

hours, her finger began to swell and was increasingly uncomfortable. No other injury was

sustained and she attended her local general practitioner (GP) practice for further advice.

Examination

On examination there was soft tissue swelling and a partially flexed little finger that the

patient was unable to completely straighten. There was no evidence of skin breach and

the patient was otherwise fit and healthy. Concerned that a fracture had been sustained,

the GP referred her to hospital for an X-ray and definitive treatment (Figure 3.1a,b).

(a)

(b)

Figure 3.1 (a) Oblique and (b) lateral radiographs of right little finger.

Questions

• What does this radiograph show?

• What other sites are commonly involved in this form of injury?

• How are X-rays made?

ANSWER 3

Figure 3.1a is a single oblique radiograph of the right little finger of adequate quality and

penetration. There is partial flexion of the distal interphalangeal joint (DIPJ) with a small

bony fragment seen in the dorsal aspect of the distal phalynx that is separated from the

parent bone. Reduced cortication of the separated surfaces in association with general-

ized soft tissue swelling is in keeping with an acute fracture, and the bony fragment has

been retracted proximally. These appearances are most likely related to a hyperflexion

injury, with a fragment of bone avulsed by the extensor tendon at its insertion into the

distal phalynx. In summary, there is an avulsion fracture to the distal phalynx of the

right little finger.

The term ‘avulsion’ is used medically to describe one part of the body forcibly detached

from another in response to trauma. Commonly seen in the accident and emergency

department related to skin degloving from road traffic accidents and nail bed trauma

from a crush injury, radiological avulsion fractures occur when a bony fragment is sepa-

rated from the parent bone in response to forcible contraction of a ligament or tendon.

During puberty, secondary ossification centres lay down advancing margins of new bone

for continued growth and development, with muscle insertions at this site forming the

‘apophysis’. The newly ossified bone is a site of weakness and is vulnerable to separation

under extreme force. Any bone subjected to a forceful and usually unbalanced muscle

contraction is subject to potential injury, however avulsion fractures are most often seen

in active adolescent children commonly at muscle insertions into the pelvis. Sprinters,

footballers and tennis players are at greatest risk of such injury. The three commonest

sites of pelvis apophyseal avulsion, as shown in Figure 3.2, are:

• ischial tuberosity at the insertion of the adductor magnus muscle of the hamstring;

• anterior inferior iliac iliac spine at the insertion of the rectus femoris muscle; and

• anterior superior iliac spine at the sartorius muscle insertion.

Anterior Superior

Iliac Spine

Anterior Inferior

Iliac Spine

Ischial Tuberosity

Figure 3.2 Annotated plain film of pelvis.

First discovered by the German physicist W.C. Roentgen in 1895, the discovery of X-rays

changed the landscape of medicine forever. To train as a radiologist, the basic physics of

X-ray production need to be understood. Every atom is made up of a positively charged

nucleus with numerous negatively charged electrons of different energy levels electro-

statically held in place around it. Superheating a metal filament (e.g. tungsten) allows

a negatively charged electron to free itself from the atom, and this can be accelerated

along an X-ray tube attracted by a positively charged ‘anode’ target plate (also commonly

made of tungsten). The fast-moving electron strikes the target plate with such force that

it can eject a static electron from a target plate atom out of its normal stable trajectory

around its nucleus. This makes the target atom unstable, and to protect itself, another

static electron encircling the same nucleus will demote itself from a higher energy band

to plug the hole left by the ejected electron. In doing so, it releases energy in the form of

a single photon called an ‘X-ray’.

Rapidly repeating this procedure can generate an X-ray beam, which when passed

through a human body can generate an image on X-ray sensitive material, as the X-rays

interact with tissues of differing densities (e.g. bone versus fat).

KEY POINTS

• Avulsion describes the forcible detachment of one part of the body from another in

response to trauma.

• A high index of suspicion of a pelvic apophyseal avulsion in athletic but skeletally

immature adolescents is advisable.

• X-Rays were discovered in 1895 by W.C. Roentgen.

ANSWER 4

The differential diagnosis for dysphagia is usefully split up into anatomical regions cor-

responding with the phases of swallowing (i.e. oral, pharyngeal and oesophageal). The

type of symptom and the most appropriate investigations depend on whether the problem

is primarily oropharyngeal or oesophageal.

Oropharyngeal dysphagia can be caused by:

• central neurological disorders such as stroke, brainstem tumours or degenerative dis-

eases (e.g. Parkinson’s disease, multiple sclerosis and Huntington’s disease);

• peripheral neurological disorders including peripheral neuropathy, poliomyelitis and

syphilis;

• systemic disorders such as myasthenia gravis, polymyositis, dermatomyositis or mus-

cular dystrophy;

• oropharyngeal lesions including cricopharyngeal achalasia, tumours, inflammatory

masses, Zenker’s diverticulum, oesophageal webs, extrinsic structural lesions, anterior

mediastinal masses and cervical spondylosis; see Case 66.

Oesophageal dysphagia can be caused by:

• achalasia;

• spastic motor disorders, such as diffuse oesophageal spasm, hypertensive lower

oesophageal sphincter and nutcracker oesophagus;

• scleroderma;

• obstructive lesions, such as tumours, strictures, lower oesophageal rings (Schatzki

rings), oesophageal webs, foreign bodies, vascular compression and mediastinal

masses.

Endoscopy is the investigation of choice for both oropharyngeal dysphagia, which is

typically investigated in the ear, nose and throat department, and oesophageal dysphagia,

which is investigated in the upper GI gastroenterology department. If endoscopy does not

provide the answer, or the patient refuses the test, then a contrast swallow test can be

done to visualize swallowing function. Videofluoroscopy is a low X-ray dose film of the

very fast swallowing action in the oropharynx and is useful if there is a motor problem

or unsafe swallow. A barium swallow is a series of images taken of the oesophagus while

swallowing barium contrast.

This patient’s symptoms are suggestive of a pharyngeal or oesophageal problem. On the

fluoroscopy images there is barium pooling in an oesophageal diverticulum arising from

the posterior midline of the upper oesophagus, the typical position for a pharyngeal

pouch (Zenker’s diverticulum). This is thought to be caused by spasm or uncoordinated

peristalsis of the upper oesophageal sphincter and is located in Killian’s triangle, formed

by the overlap of the oblique muscles of the inferior constrictor muscle and the transverse

muscle fibres of the cricopharyngeus muscle.

The patient’s symptoms probably reflect progressive increase in size and compressive

effect of the pouch. There is also increased risk of aspiration. The treatment is usually

surgical excision or endoscopic stapling. The cricopharyngeal muscle may be separated to

prevent recurrence. Complications of pouches include aspiration and, rarely, a carcinoma

within the pouch.

Diverticula in other positions are possible. A Killian-Jamieson diverticulum is a lateral

cervical oesophageal diverticulum just a little lower in position. Pulsion diverticula asso-

CASE 5: A MECHANICAL FALL IN AN ELDERLY PATIENT

History

An 81-year-old woman is bought into the accident and emergency department by ambu-

lance from a local nursing home. As a long-term resident of the home she is an active

participant in daily activities, and is usually self-caring and independent. Yesterday

evening, she sustained a witnessed mechanical fall, tripping over the walking stick of

another resident. Despite a small graze to the right side of the head, there was no loss of

consciousness and the patient reassured care home staff that she was fine. An incident

report was filed. During the night the patient took paracetamol for pain control of a

headache but no further action was taken.

In the morning, she complained of continued headache and the care staff noted a general

listlessness and drowsiness. During the course of the day this progressed, and the patient

was found slumped in her chair before lunch, rousable only to strong verbal commands.

Staff were worried and called an ambulance.

Examination

On inspection the patient had a superficial graze to the right side of her forehead. Her

Glasgow Coma Scale (GCS) was 11 (motor 5, eyes 3, speech 3). She was apyrexial, pulse

76 regular, normotensive with a normal cardiovascular examination. There was no focal

neurological deficit, and both pupils were equal and reactive. An unenhanced computed

tomography (CT) scan was performed (Figure 5.1).

Figure 5.1 Unenhanced CT scan.

Questions

• What does the CT scan demonstrate?

• What is the diagnosis and treatment?

ANSWER 5

This is a single unenhanced image from a cranial CT scan at the level of the basal ganglia.

There is an area of asymmetry between the inner table of the skull and the brain in the left

cerebral hemisphere. This is more dense than adjacent brain parenchyma but not as dense as

the calcified bones of the skull. It conforms to the skull in a concave shape and is predomi-

nantly homogeneous in appearance. The adjacent sulci are effaced, as they are not traceable

to the brain surface compared to the contralateral side. There is also slight effacement of

the left lateral ventricle with some mild midline shift to the right. The brain parenchyma

demonstrates preserved grey/white matter differentiation, and there is some generalized

cerebral atrophy, demonstrated by increased sulcal spaces seen in the normal right cerebral

hemisphere. These findings are in keeping with a subdural haemorrhage with mass effect.

Subdural haemorrhage is defined as a collection of blood in the space between pia mater

and dura mater of the leptomeninges.

Laceration of the veins between the two inner layers of the meninges causes blood to

accumulate in the subdural space. Although there is an association with direct head

trauma and penetrating injury, subdural haematomas are most commonly seen within

the elderly population. The brain atrophies with age and becomes more mobile within the

skull. The bridging cortical veins are stretched, increasing the risk of both spontaneous

rupture and disruption after trivial head injury. Blood is free to track along the surface of

the brain within the subdural space and is limited only by the falx and tentorium cerebel-

lum. Cranial CT demonstrates a concave haematoma that, unlike an extradural haemor-

rhage, crosses suture lines within the skull. The haematoma can have a varied attenuation

pattern depending on whether it is an acute, subacute or chronic subdural haemorrhage.

For example, Figure 5.2 demonstrates bilateral chronic subdural haemorrhages. In some

cases where there is rebleeding, layering of

old and fresh blood can be seen, demon-

strating an acute-on-chronic picture.

These types of intracranial bleeds tend to

be venous in aetiology and blood accu-

mulates slowly in the subdural space.

Treatment depends on the neurologi-

cal deficit caused by the haemorrhage.

Patients commonly present with headache,

sleepiness and personality change, but

if the bleed is large, the conscious level

can fluctuate. Signs and symptoms of

raised intracranial pressure can occur late

and should alert clinicians to the need of

urgent evacuation and decompression via

a burr hole in a specialist neurosurgical

Figure 5.2 CT scan showing bilateral chronic

centre. Patients can make a full recovery.

subdural haemorrhages.

KEY POINTS

• In a subdural haemorrhage, blood collects between the pia and dura mater.

• Subdural haemorrhages are more common in the elderly population due to cerebral

atrophy.

• Computed tomography demonstrates a concave haematoma unlimited by cranial sutures.

CASE 6: RIGHT UPPER ABDOMINAL PAIN

History

A 45-year-old woman presents to the accident and emergency department complaining

of continuous right upper quadrant pain. This has been worsening over the last 12 hours.

Previously the patient has had intermittent pain in the same area lasting up to a few

hours after eating. She had tried some antacids with no benefit. There has been no vom-

iting. She complains of irregular bowel pattern, predominantly loose, smelly and rather

pallid stool for some months. There is no significant past history and she does not take

regular medication.

Examination

The woman appears well but in discomfort with normal observations. The cardiovascular

and respiratory examination is normal. The abdomen is soft but focally tender over the

right liver edge. The liver is not enlarged. There is no renal angle tenderness.

You arrange tests including an ultrasound of the abdomen (Figure 6.1).

(a)

(b)

Figure 6.1 Ultrasound views of the liver and gallbladder in longitudinal (a) and transverse

(b) planes.

Questions

• What differential diagnoses are you considering?

• What does the ultrasound show?

• Is ultrasound the best investigation to start with?

ANSWER 6

The stool appearance and Murphy’s point tenderness point to gallbladder inflammation

although the differential includes liver pathology, pancreatitis, gastric or duodenal ulcer,

renal obstruction or infection.

The ultrasound shows a partially filled gallbladder with a thickened irregular layered

oedematous wall (>3 mm). The gallbladder contains two small stones that reflect virtu-

ally all of the beam, giving a shadow appearance behind the stone. A stone is seen in the

gallbladder neck and part of the ultrasound examination is to roll the patient onto the

right side to see if the stones are mobile. In this case the stone is fixed at the gallbladder

neck. These are the appearances of acute obstructive cholecystitis.

For suspected gallbladder or biliary abnormalities, an ultrasound is a good starting inves-

tigation. Ultrasound has a very high sensitivity for gallstones whereas at least 20 per cent

of gallstones are not seen on computed tomography (CT). Biliary dilatation is also easily

seen on ultrasound, appearing as an extra tube running alongside the intrahepatic portal

veins (double-barrel sign) or as an extrahepatic dilated common bile duct. Sometimes the

cause of obstruction is seen, although the proximity of gas in the stomach, duodenum

and hepatic flexure of the colon can often obscure extrahepatic causes. An abdominal

radiograph is often included in the work up and is helpful to look for other causes such

as renal stones causing colic. Only 30 per cent of gallstones contain enough calcium to

be radio-opaque and visible on the abdominal radiograph.

The signs of cholecystitis are also seen frequently on CT that may be done if there is

uncertainty as to the diagnosis (Figure 6.2).

Cholecystitis results from obstruction of

the cystic duct and in about 90 per cent

of cases this is caused by a calculus. In

80 per cent these are cholesterol based,

20 per cent are pigment based. A few

cases are caused by sludge that is a fine

calcified sediment that forms if the bile

becomes very concentrated. The remainder

are acalculous cholecystitis, which has all

the inflammatory signs without stones and

tends to occur in systemic illness, biliary

stasis and local or systemic ischaemia.

Rarely, gas within the gallbladder or bil-

iary tree is seen if there is added infection.

Figure 6.2 Axial contrast CT scan through

the gallbladder showing fluid around the

gallbladder.

KEY POINTS

• Ultrasound is a good test for gallbladder and biliary problems.

• Murphy’s sign - focal tenderness over the gallbladder - is frequently elicited by the

pressure of the ultrasound probe.

• Look on the ultrasound for gallstones, gallbladder wall thickening and oedema as signs

of cholecystitis and gas as a sign of infection.

CASE 7: HEARTBURN, EPIGASTRIC PAIN AND A COUGH

History

A 67-year-old man presents to his general practitioner (GP) with a cough. The man was

well known to the doctor as he had been a regular attendee over the course of the previ-

ous 12 months with recurrent chest infections. His background included longstanding

symptoms of heartburn, dyspepsia and epigastric pain, for which he was prescribed a

regular proton pump inhibitor (with some relief). He took no other medications, however,

and lived at home with his wife.

Examination

No abnormalities were found on examination of the chest. His respiratory rate was 18

breaths per min with equal and good air entry bilaterally, vesicular breath sounds with

no added sounds. He was referred for a chest radiograph (Figure 7.1) but on the basis of

the radiograph the reporting radiologist suggested an upper gastrointestinal (GI) contrast

swallow examination (Figure 7.2). One day following the barium swallow examination

the patient presented acutely in the accident and emergency department with symptoms

of epigastric pain, and a computed tomography (CT) scan was performed (Figure 7.3).

Figure 7.1 Chest radiograph.

Figure 7.2 Upper GI contrast swallow exam.

Questions

• What does the plain chest radiograph

demonstrate (Figure 7.1)?

• Why would the radiologist suggest a

barium swallow examination?

• What do the barium swallow spot

image (Figure 7.2) and axial enhanced

CT image (Figure 7.3) show?

Figure 7.3 CT scan.

ANSWER 7

Spot images taken from a barium swallow examination confirm the presence of a sliding

hiatus hernia (Figure 7.2). The axial enhanced CT image (Figure 7.3) again demonstrates

a large sliding hiatus hernia extending into the thorax. The chest radiograph shows a

gas-filled viscus behind the heart shadow consistent with a hiatus hernia. An upper GI

contrast examination would confirm the presence of a hiatus hernia and any associated

gastro-oesophageal reflux to account for the patient’s symptoms.

A hiatus hernia occurs when part of the stomach protrudes into the thoracic cavity

through the oesophageal hiatus of the diaphragm. Hiatus hernias are classified either

as sliding hernias (where the gastro-oesophageal junction moves above the diaphragm

together with part of the stomach) or para-oesophageal or ‘rolling’ hiatus hernias (where

part of the stomach herniates through the oesophageal hiatus and lies beside the oesopha-

gus without movement of the gastro-oesophageal junction). Approximately 95 per cent of

hiatus hernias are sliding and the remaining 5 per cent are para-oesophageal.

Plain chest radiographs (as in Figure 7.1) may demonstrate a retro-cardiac mass with or

without an air-fluid level. When air is seen within the hernia, the stomach air bubble

found below the diaphragm tends to be absent. The hernia is usually positioned to the left

of the spine, however larger hernias (particularly when incarcerated) may extend beyond

the cardiac confines and even mimic cardiomegaly.

An upper GI barium series (as in Figure 7.2) is the preferred examination in the investiga-

tion of hiatus hernia and its sequelae. A single-contrast barium swallow performed with

the patient prone is more likely to demonstrate a sliding hiatal hernia than an upright

double-contrast examination. The hernia can usually be recognized by the demonstration

of mucosal gastric folds. CT scans are useful when more precise cross-sectional anatomic

localization is desired.

Most hiatus hernias are actually found incidentally, often being discovered on routine

chest radiographs or CT scans performed for unrelated symptoms. When symptomatic,

common symptoms include heartburn, dyspepsia or epigastric pain. On occasions, as in

this case, the patient may present with recurrent chest infections resulting from aspiration

of gastric contents. One sequel of hiatus hernia (particularly the sliding form) is the devel-

opment of Barrett’s oesophagus, which may present with reflux symptoms or dysphagia.

With a para-oesophageal or rolling hernia, part of the stomach rolls into the thorax often

anterior to the esophagus and is frequently irreducible. Therefore this type of hernia is

more likely to present acutely because of a volvulus or strangulation. A para-oesophageal

hiatal hernia is diagnosed by the position of the gastro-oesophageal junction. The cardia

of the stomach and gastro-oesophageal junction usually remain in the normal position

below the diaphragmatic hiatus and only the stomach herniates into the thorax adjacent

to the normally placed gastro-oesophageal junction. This type of hernia, (unlike the slid-

ing form) is not associated with gastro-oesophageal reflux.

KEY POINTS

• Hiatus hernias are frequently diagnosed incidentally on routine chest radiographs.

• The hernia may be seen as a retro-cardiac mass with or without an air-fluid level.

• An upper GI barium series or barium swallow study is the examination of choice

for demonstrating a hiatus hernia, gastro-oesophageal reflux and any associated

complications (e.g. Barrett’s oesophagus).

• A para-oesophageal or, rarely, sliding hiatal hernia may present acutely because of

a volvulus or strangulation.

CASE 8: LINES, CATHETERS AND TUBES ON A RADIOGRAPH

History

A 59-year-old woman has recently been admitted to the intensive care department. She

has chronic renal failure and relies on peritoneal dialysis every night. This morning,

while attending her clinic appointment, she complained of a sudden onset of headache

and collapsed to the ground, shaking violently. The emergency ‘crash’ team were called

immediately and found the patient unresponsive with generalized jerking movements.

The senior doctor decided that she should be paralysed, intubated and ventilated for pro-

tective measure, and she was then transferred to the intensive care department for further

management. The patient was satisfactorily stabilized, and a central line was placed in

her right internal jugular vein for the infusion of intravenous medication and to monitor

her central venous pressures. A chest radiograph has been performed to confirm correct

placement before its use (Figure 8.1), which you have been asked to report.

Figure 8.1 Chest radiograph.

Questions

• What additional lines and tubes does this radiograph demonstrate?

• Are the lines and tubes correctly positioned?

• What other common medical equipment may be seen on a radiograph?

ANSWER 8

Any radiograph can be complicated by additional shadows from foreign lines or drains.

Their presence implies that the patient is unwell, and it is important to not only recognize

the type of line and common complications associated with its insertion, but its presence

on the film should not be a distraction to reporting pathological change (for example,

left lower lobe collapse in Figure 8.2). These types of films are often mobile examinations

from intensive care (ITU) patients and can be complicated by rotation, poor inspiratory

effort and an anterior-posterior (AP) projection. The commonest lines are discussed

below, with chest drains discussed in a separate case; see Case 27.

Nasogastric tube on

patients skin

Endotracheal tube

Cardiac monitoring

Right internal jugular

wire

central venous catheter

Nasogastric tube as

it passed GOJ

Figure 8.2 Chest radiograph with labels.

• Endotracheal (ET) tubes: A patient is intubated for reasons of mechanical ventilation

and airway protection usually because they are critically ill or undergoing anaesthe-

sia. Correct placement is critical and an ET tube is recognized on a chest radiograph

as a linear opacity projected over the trachea in the midline. Insertion of an ET tube

is beyond the scope of this book, but once in the trachea a radiolucent balloon cuff is

inflated to maintain stability and a mechanical seal. The tubes are positioned blindly by

an airway expert and a chest radiograph is used to confirm its position. Ideally, the tip

of an ET tube should be located within the trachea, approximately 1-2 vertebral body

heights above the carina. This allows ventilation of both lungs and incorrect placement

should be highlighted urgently to the referring clinician. The commonest abnormality is

advancement of the ET tube into the right main bronchus preferentially ventilating the

right lung only. If not corrected, the patient may be compromised by left lung collapse.

An example of an ET tube in the right main bronchus is given in Figure 8.3.

Figure 8.3 Chest radiograph showing ET tube

in right main bronchus.

• Nasogastric (NG) tubes: These are placed in patients for numerous reasons, most com-

monly nutritional. Correlating the position of an NG tube does not necessarily require

a chest radiograph. Testing the pH of the aspirate can confirm placement within the

stomach, thereby avoiding unnecessary radiation exposure. If this is not possible, a

chest radiograph should demonstrate the NG tube as a midline linear opacity extend-

ing below the left hemidiaphragm. This confirms its presence in the stomach and not

in a main stem bronchus, avoiding the catastrophic infusion of nutritional support

into the lungs. The tip of an NG tube is not always seen on the chest radiograph, but

should lie within the stomach. It can sometimes migrate into the duodenum with gas-

tric peristalsis and should be partially withdrawn.

• Central lines: Primarily placed in patients for the infusion of intravenous medication,

central lines can also avoid the need for peripheral cannulation and risks of thrombo-

phlebitis. A chest radiograph is performed post insertion to confirm tip position and

exclude the most serious complication of pneumothorax. A central line is a radio-

opaque density projected paramedially over the internal jugular or subclavian vessels,

and can have a wide variety of appearances depending on the side it is inserted and

how many lumens the line contains (Figure 8.4). It may also be tunnelled under the

skin in the case of a Hickman line, with the possible addition of a buried metallic

port (portacath). Recognizing the type of line is important but not essential. Correct

tip positioning is critical for optimal infusion. The tip of a central line should ideally

lie at the confluence of the inferior and superior vena cava as blood drains into the

right atrium. This is identified on a chest radiograph at a point approximately one

vertebral body height below the carina. A short line position carries thrombotic risks,

while overenthusiastic advancement into the right atrium can encourage myocardial

excitation and atrial ectopics.

• Others: ET tubes are not suitable for patients requiring long-term ventilatory support

and often a tracheotomy is inserted just inferior to the cricoid cartilage. Lying in the

midline within the superior mediastinum, a tracheotomy tube appears as a radio-

opaque curvilinear density with a buttressed cuff at the skin surface. Its tip should lie

within the trachea above the carina.

Figure 8.4 also shows cardiac monitoring and pacing equipment. The two paddle-shaped

radio-densities are adhesive conducting pads, and are used to monitor a patient’s heart

rhythm, control the heart rate through electrical pacing and can be used to deliver an

electrical cardioversion shock if necessary. They are correctly positioned here along the

electrophysiological axis of the heart. Continuous cardiac monitoring is performed by

CASE 9: WEAKNESS AND SLURRING WHILE OUT FOR A DRINK

History

A 67-year-old man is bought into the accident and emergency department by ambulance

with new left-sided limb weakness and a left facial droop. This started 40 minutes earlier

while the patient was having a pint in his local pub. Complaining of dizziness for a short

while, the patient suddenly fell from his bar stool. The concerned bar tender managed to

help him to an armchair and noticed that he was slurring his words and could not use his

left arm to help himself up. An ambulance was called, and during this time the patient

developed a left-sided facial droop. He remained alert throughout but appeared anxious

and disorientated.

The patient is known to the hospital, and has attended previously with attacks of angina.

There is no history of myocardial infarction, but he is on tablets for hypertension and

dyslipidaemia. He is a smoker and lives at home with his wife. There have been no recent

intercurrent illnesses.

Examination

A computed tomography (CT) scan was performed as part of his medical assessment

(Figure 9.1).

Figure 9.1 CT scan.

Questions

• What does the CT scan show?

• What is a stroke?

• What are the treatment options?

ANSWER 9

This (Figure 9.1) is a single image from an unenhanced CT scan acquired at the level of

the corona radiata. There is a background of generalized involutional change in keeping

with the patient’s age, and some hemispheric white matter low attenuation suggestive

of small vessel disease. Within the right fontal lobe there is a wedge-shaped area of low

attenuation with loss of the normal grey/white matter differentiation and extension to the

cortical surface. There is mass effect with the adjacent sulci effaced, but no evidence of

midline shift or hydrocephalus. There is no evidence of haemorrhage or mass lesion. The

image findings are consistent with an acute right middle cerebral artery (MCA) infarction

on a background of generalized ischaemic change.

Any vascular interruption within the brain starves distal tissues of blood causing cell

death and neurological deficit. This is termed a ‘stroke’ and is usually thromboembolic

(90 per cent) in aetiology,¹ and less commonly haemorrhagic. In the acute setting,

unenhanced cranial CT is used to differentiate between the two. Treatment pathways for

infarction require antiplatelet therapy, but haemorrhage needs to be excluded to avoid

the catastrophic effects of anticoagulation.

Figure 9.2 demonstrates an acute intracerebral haemorrhage within the left cerebral

hemisphere. Cranial CT has a high sensitivity (89 per cent) for haemorrhagic stroke.

Acute blood within the brain parenchyma appears white on CT (attenuation Hounsfield

unit (HU) of 60-70) and stands out against the adjacent darker brain tissue. Treatment

for haemorrhagic stroke is usually conservative and supportive.

Figure 9.2 CT scan showing acute

intracerebral haemorrhage.

In acute infarctive stroke, cranial CT is relatively insensitive (45 per cent at ictus rising

to 74 per cent by day 11)¹ and radiological features can vary. A normal cranial CT does

not exclude thromboembolic stroke, and should neurological deficit fully resolve within

24 hours, this is termed a transient ischaemic attack (TIA). The significance of patients

presenting with a TIA should not be underestimated, and these patients should be consid-

ered as an acute medical emergency requiring risk stratification to prevent further non-

fatal disabling stroke. In the setting of an acute infarctive stroke or TIA, the cranial CT

may be normal. Large thromboembolic strokes classically demonstrate a wedge-shaped

area of low density with blurring of the grey/white matter junction. In the image from the

CT scan taken from our patient (Figure 9.1), there is loss of grey/white matter differentia-

tion within the right fronto-parietal region compared to the contralateral side. This area

is shaded grey in Figure 9.3, which shows the subtle features of an acute thomboembolic

stroke.

Figure 9.3 CT scan.

In larger infarctive strokes, associated vasogenic oedema can press upon adjacent brain

tissue and cause mass effect. The CT findings can usually localize the cerebral artery

involved, most commonly the middle cerebral artery (MCA). Figure 9.4 shows an unen-

hanced axial CT slice demonstrating a well-demarcated area of low attenuation, with

loss of the grey/white matter interface and mass effect, in keeping with a large acute left

MCA infarct.

Figure 9.4 Unenhanced axial CT slice.

Many hospitals are now offering thrombolysis therapy for acute thromboembolic stroke.

Any history of intracranial haemorrhage is an absolute contraindication, and perform-

ing and interpreting a cranial CT is therefore essential prior to treatment. Some other

contraindications are listed in Table 9.1 in the criteria taken from the National Institute

of Health and Clinical Evidence (NICE) guidance.² Thrombolysis therapy has to be admin-

istered within 3 hours of symptom onset and speed of brain imaging is very important.

Without revascularization, neuronal demyelination causes atrophy of brain tissue with

time, and the patient is left with a permanent neurological deficit. In the case of our

67-year-old patient, he may qualify for stroke thrombolysis and a senior stroke physician

should initiate this quickly all criteria having been met.

Table 9.1 Criteria taken from the National Institute of Health and Clinical Evidence (NICE)

guidance²

Inclusion criteria

• Clinical signs and symptoms of a definite acute stroke

• Clear time of onset

• Presentation with 3 hours of onset

• Haemorrhage excluded by CT scan

• Aged between 18 and 80 years

Contraindications

• Any significant bleeding disorder within the last 6 months

• Any significant head injury within the last 3 months

• Current warfarin treatment and an international normalized ratio (INR)

>1.4

• Suspected subarachnoid haemorrhage with a normal CT

• Acute pancreatitis

• Bacterial pericarditis or endocarditis

• Active hepatitis or portal hypertension

• Documented bleed from abdominal aortic aneurysm (AAA) in last

3 months

KEY POINTS

• Acute thromboembolic stokes classically demonstrate a wedge-shaped area of low

attenuation with blurring of the grey/white matter junction.

• Transient ischaemic attacks (TIAs) should be treated as a medical emergency as a sign

of impending stroke.

• Many hospitals now provide systemic thrombolysis for the treatment of acute

thromboembolic stroke.

References

1. Dahnert, W. (2007) Radiology Review Manual, 6th edn. Philadelphia: Lippincott Williams and

Wilkins.

2. National Institute for Health and Clinical Excellence (2007) Alteplase for the treatment of acute

ischaemic stroke. www.guidance.nice.org.uk/TA122.

CASE 10: BACK PAIN RELIEVED ONLY BY ASPIRIN

History

A 23-year-old caucasian man presented to the accident and emergency department (A&E)

with back pain. Usually fit and healthy, he has suffered from achy throbbing back pain

for the last 6 months. Always in the same position in his lower back, it is there intermit-

tently but has increased in frequency over the last 2 weeks. The pain is worse at night and

it often wakes him from sleep. He denies any trauma, weight loss or symptoms related to

his bladder or bowel movements.

His general practitioner diagnosed occupation-related back pain in relation to the

patient’s job as a farmer, and recommended rest while prescribing several combinations

of analgesia with little symptomatic relief. He does describe marked improvement in his

symptoms with aspirin, but the pain often returns after only an hour. Waking up tonight,

he was frustrated with the pain at home and attended A&E.

Examination

On examination he looks healthy but in mild discomfort. He has full range of move-

ment with no evidence of bony tenderness on palpation. Cardiovascular, respiratory and

abdominal systems are normal. X-ray is shown in Figure 10.1.

Figure 10.1 Plain radiograph.

Questions

• What does the plain radiograph demonstrate?

• What is your differential for these findings?

• What further investigations need to be performed?

ANSWER 10

Figure 10.1 is a plain anterior-posterior (AP) radiograph of the lower thoracic and lumbar

spine in an adult male patient. The vertebral bodies demonstrate normal alignment in the

AP view with normal vertebral body height preserved throughout. There is an abnormal-

ity centred on the right L4 pedicle with expansion of the cortex and dense sclerosis. The

adjacent transverse process also appears expanded compared to the contralateral side but

there is no evidence of periosteal reaction. The psoas muscle shadow is preserved, making

psoas abscess unlikely and there is no evidence of a large soft tissue component. There

is no evidence of fracture but a mild scoliosis is demonstrated at this level concave to

the right.

The differential for these appearances in a young caucasian man includes:

• osteoid osteoma;

• osteoblastoma;

• healing fracture;

• sclerosing osteomyelitis (e.g. tuberculosis, syphilis);

• Brodie’s abscess;

• osteoblastic metastasis;

• lymphoma;

• primary bone tumour (e.g. osteosarcoma).

Further radiological imaging is recommended and a choice needs to be made as to which

modality will provide the best diagnostic yield with minimal inconvenience and radia-

tion dose to this young patient. Considering the likely osseous location of the lesion, a

computed tomography (CT) scan would have superior resolution compared to magnetic

resonance imaging (MRI). Bone scintigraphy would also be beneficial but not as the first-

line imaging modality following a plain film radiograph.

Figure 10.2 is a single axial slice of an unenhanced CT scan acquired at the level of the

L4 vertebral body viewed with bone windows. Within the right pedicle there is a well-

defined 17 mm lesion (arrow) that has a narrow zone of transition and is predominantly

lytic in nature with some central calcification. There is diffuse sclerosis and expansion

of the adjacent lamina and transverse process, with no evidence of periosteal reaction,

spinal canal encroachment or pathological fracture. No soft tissue component is demon-

strated. These features are in keeping with an osteoid osteoma, however considering its

size (>15 mm) it is more appropriately described as an osteoblastoma.

Osteoid osteoma

Figure 10.2 Unenhanced CT scan.

Osteoblastomas are rare benign tumours of the bone composed of multinucleated osteo-

clasts with irregular trabeculated bone and osteoid, surrounded by highly vascular fibrous

connective tissue.¹ The commonest sites of involvement are around the knee joint in the

long bones and within the posterior elements of the spine. They have unlimited potential

for growth and carry a risk of malignant degeneration, therefore requiring definitive

curative treatment at diagnosis.

The main treatment options include surgical removal, endovascular embolization, per-

cutaneous CT-guided removal or percutaneous radiofrequency ablation. In this case,

endovascular treatment was attempted (Figure 10.3).

Figure 10.3 Angiographic image at embolization.

This angiographic image obtained at embolization (Figure 10.3) demonstrates a blush of

contrast overlying the pedicle of the L4 vertebrae on selective cannulation of the right

L4 lumbar artery. The arterial supply to this osteoblastoma was embolized with polyvinyl

alcohol (PVA) and two microcoils. Follow-up 2 months later revealed an asymptomatic

patient, and successful treatment was confirmed on CT with complete sclerosis at the site

of the previous osteoblastoma (Figure 10.4).

Figure 10.4 CT scan post embolization.

CASE 11: A PERSISTENT COUGH IN AN EX-SMOKER

History

You are asked to review a 67-year-old man in the chest clinic. He has been sent by his

general practitioner (GP) who has been treating him for a cough. His symptoms started

3 weeks ago, at about the same time that the patient decided to stop smoking. The cough

is chesty but non-productive, and is there constantly, but not worse, at night. He has no

other new symptoms and is no more short of breath than usual, with an exercise toler-

ance of approximately 200 m. His appetite is unchanged and he has not lost weight. He

does report occasional streaks of fresh red blood in the sputum on deep coughing.

The patient has a past medical history of excessive alcohol intake and chronic obstruc-

tive pulmonary disease (COPD). He had two previous admissions to hospital with decom-

pensated liver disease, but has now abstained from alcohol for over a year. His last

ultrasound scan confirms a degree of liver cirrhosis. He has smoked with a 60 pack-year

history. He has never been admitted to intensive care with exacerbations of COPD, but

has been treated for pneumonia in the past. He recently decided to stop smoking as his

new girlfriend does not like to ‘kiss an ashtray’.

Examination

As part of his management, the GP performed a chest radiograph (Figure 11.1) and then

referred him to the chest clinic.

Figure 11.1 Chest radiograph.

Questions

• What does this chest radiograph demonstrate?

• What further radiological investigations are required?

• What is PET scanning?

ANSWER 11

This is a diagnostically adequate posterior-anterior (PA) chest radiograph of an adult male

patient. There is a 2.3 cm rounded mass lesion within the left mid zone adjacent to the left

hilum that appears to cavitate in its inferior aspect. No other pulmonary parenchymal nod-

ularity is seen. There is blunting of the costophrenic angles bilaterally which may represent

either small pleural effusions or be longstanding related to pleural thickening. There is a

background of emphysematous change as evidenced by lung hyperinflation and flattening

of the hemidiaphragms. Bilateral gynaecomastia is also noted. The rounded lesion may rep-

resent a malignancy in the form of a lung primary in view of the clinical history, however

a focus of infection or metastasis cannot be excluded. Correlation with old films is advised.

The suspicious nature of this pulmonary mass lesion warrants a computed tomography

(CT) scan, which ideally should be performed with intravenous contrast. Although the

chest X-ray only demonstrates a solitary lesion, a CT scan of the chest and abdomen is

recommended. This allows characterization of both the lungs and mediastinum, and also

assesses the solid abdominal viscera (e.g. liver and adrenals), which are sites of common

involvement in disseminated lung cancer. Extending the CT to involve the abdomen

allows for accurate staging of primary lung cancer, and the patient can be referred to the

lung multidisciplinary meeting (MDM) for further discussion.

The CT scan confirms a background of centrilobular emphysema and a left lower lobe

pulmonary nodule measuring 2.6 × 1.6 cm (Figure 11.2). This tethers the oblique fissure

and demonstrates an adjacent airspace opacification with cavitation. No disease was seen

in the contralateral lung, mediastinum or below the diaphragm. Findings are compatible

with a primary bronchial malignancy.

Figure 11.2 Sagittal CT scan.

The patient was then referred to the MDM. Time is an important factor to limit the spread

of disease, and efficient transfer of patient care through the relevant specialities is of

utmost importance to expedite definitive treatment.

A tissue diagnosis is important to obtain histological characterization of the lesion.

Although cavitation and a history of smoking infers a likely squamous cell aetiology,

histological confirmation is essential to tailor further chemotherapy or surgical treatment.

The location of this lung primary would necessitate a CT-guided biopsy under the aus-

pices of the interventional radiologists. A coaxial needle system is passed under CT guid-

ance and local anaesthetic cover into the lesion, and a core biopsy sample taken (Figure

11.3). Patients should be consented for the risk of lung contusion and pneumothorax.

Figure 11.3 Biopsy under CT guidance.

A positron emission tomography (PET) scan is indicated in potentially operable tumours

to assess nodal status and occult metastatic disease. This is required for complete disease

staging and will dictate further treatment. If the PET scan confirms that this lesion is soli-

tary and there is no evidence of nodal or metastatic spread, then the patient may be eligible

for definitive surgery in the form of lobectomy if medically fit, although careful assess-

ment will be needed in view of his significant COPD. Should the PET scan suggest inoper-

able or disseminated disease, then a chemotherapeutic treatment may be more appropriate.

A PET scan is a nuclear medicine scan, usually performed in combination with a CT scan.

PET uses a radioactive isotope with a short half-life (e.g. fluorine-18 (F¹⁸)), which is bio-

chemically incorporated into the functionally active glucose molecule fluorodeoxyglucose

(FDG). It is used extensively in oncology imaging because the FDG-F¹⁸ is concentrated

in metabolically active tissues, radiolabelling those tissues with high amounts of glucose

uptake. Although there is physiological uptake in organs such as the brain, heart and

liver, primary cancers and their metastases can also be detected by the PET scanner, as the

F¹⁸ undergoes positron emission decay. The images obtained are fused with unenhanced,

attenuation corrected CT images taken concurrently for anatomical correlation.

CASE 12: A SCHOOLMASTER WITH PROGRESSIVE

BREATHLESSNESS

History

A 64-year-old man is referred to the respiratory outpatient clinic for assessment. He

gives a history of a shortness of breath which has been insidious in onset over the last

4 years. Over the last year, this has been associated with a dry cough which he cannot

seem to clear despite several courses of antibiotics. He feels fatigued and had found it

more difficult to complete a round of golf, which he used to do twice a week. His weight

has remained steady and he denies orthopnoea. There is no relevant past medical history.

He is a non-smoker and admits to social drinking only. He takes 75 mg aspirin daily

on advice of his general practitioner (GP) but is not on any other regular medication.

Occupationally, he is nearing retirement as a school headmaster and denies any history

of occupational dust exposure. He lives at home with his wife and keeps no pets.

Examination

On examination, he is well perfused and not cyanosed, but has evidence of nail clubbing

bilaterally. Lung expansion is reduced and auscultation demonstrates fine inspiratory

crackles, more marked at the bases.

Prearranged lung function studies demonstrate a restrictive lung defect and a chest radio-

graph was taken for assessment (Figure 12.1).

Figure 12.1 Chest radiograph.

Questions

• How would you describe the chest radiograph appearances?

• What would be the differential for these appearances?

• How is the idiopathic cause of this condition subclassified?

ANSWER 12

This is a posterior-anterior (PA) chest radiograph of an adult male patient. There is good

alignment, inspiration and penetration. The heart and hila are of normal size with an ill-

defined ‘shaggy’ heart boarder. The lungs demonstrate volume loss, most marked at the

bases with depression of the horizontal fissure on the right. There is reticular shadowing

to the lung parenchyma in a subpleural distribution with relative sparing of the apices.

There is no evidence of calcified lymph nodes or air-fluid levels within the oesophagus.

Correlation with old radiographs is recommended, but the appearances are suggestive of

pulmonary fibrosis.

Many people have difficulty with the descriptive terms of ‘reticular’ and ‘nodular’ shad-

owing. They are commonly used in chest radiograph reporting, implying clear differen-

tials and distinction between infective and interstitial causes of lung disease. Reticulation

describes lines that branch and interlace as a result of thickened interstitial septa between

secondary pulmonary lobules. Nodularity, however, describes well-defined ‘dots’, which

can vary in size and are predominantly caused by airspace opacification and imply an

infective focus. Just to confuse matters, some conditions (e.g. sarcoidosis) can be both

reticular and nodular in appearance.

In this scenario, the reticular pattern implies an underlying diagnosis of interstitial lung

disease, with volume loss suggesting a fibrotic component. The causes of these appear-

ances are numerous, and it is important to scrutinize the distribution of disease to help

narrow the differential. The causes of lung fibrosis, divided between an apical and basal

distribution, are listed in Table 12.1.

Table 12.1 Causes of lung fibrosis

Upper zone fibrosis

Lower zone fibrosis

Allergic bronchopulmonary aspergillosis

Idiopathic pulmonary fibrosis

Radiation

Drugs (e.g. amiodarone)

Extrinsic allergic alveolitis

Rheumatoid disease

Ankylosing spondylitis

Scleroderma

Sarcoidosis

Asbestosis

Silicosis

Dermatomyosytis

Tuberculosis

Histocytosis X

By history alone and in the absence of ancillary features associated with connective tissue

disease, a diagnosis of idiopathic pulmonary fibrosis is made in this patient. To confirm

and subclassify the diagnosis, the patient should be referred for a high-resolution com-

puted tomography (HRCT) chest scan. This is different from a normal ‘volume’ computed

tomography (CT) scan of the chest and is an unenhanced study, providing high-resolution

thin (1 mm) cuts of the lung parenchyma at 1 cm intervals (Figure 12.2).

This single image of the patient’s HRCT obtained within the lower zones of the chest

demonstrates areas of disruption to the normal lung parenchyma with thickening of the

interlobular septa causing a ‘honeycomb’ like appearance. These changes are predomi-

nantly confined to a subpleural distribution with preservation of the normal lung paren-

chyma centrally. This is characteristic of usual interstitial pneumonitis (UIP), a subtype

of idiopathic pulmonary fibrosis. There is clinical importance in determining the likely

subtype, as UIP is relatively insensitive to steroid therapy with a 45 per cent 5-year mor-

tality.¹ The other broad subtypes are:

• Non-specific interstitial pneumonitis (NSIP): Despite an often normal chest radio-

graph, appearances on HRCT are of patchy ground glass opacification with no clear

zonal distribution. There is no evidence of honeycomb fibrosis and this subtype is

more likely to respond to steroid therapy with an overall 5-year mortality of 11 per

cent.¹

• Desquamative interstitial pneumonitis (DIP): Seen predominantly in patients who

smoke, appearances on chest radiograph and HRCT are of both subpleural ground

glass opacification and honeycomb fibrosis. This is confined to the lower zones but is

not associated with significant volume loss. DIP has a variable steroid response with

a 50 per cent 5-year survival.¹

Figure 12.2 High resolution chest CT scan.

KEY POINTS

• Reticular shadowing with parenchymal volume loss is the characteristic feature of

pulmonary fibrosis on chest radiograph.

• It is important to scrutinise the distribution of disease within the lungs to help make the

causative diagnosis.

• HRCT is integral in characterizing the type and extent of pulmonary fibrosis.

Reference

1. Dahnert, W. (2007) Radiology Review Manual, 6th edn. Philadelphia: Lippincott Williams and

Wilkins.

CASE 13: NUMB RIGHT ARM

History

A 50-year-old man presents with a history of an intermittently numb right arm that has

become more of a problem recently after some heavy lifting. There is no history of trauma

or surgery and there is no clear history of onset although the problem has been present

for some months. He notices it most after sleeping, with forearm and hand numbness

that wears off with movement. He also has an intermittent dull ache and impression of

reduced strength, for example when trying to open jars. There is no history of Raynaud’s

phenomenon, swelling or cold hand. There is no other significant medical history.

Examination

The arms are symmetrical. There are normal peripheral pulses. There is a subjective

mild weakness on the right to flexion at the elbow with a slightly reduced biceps reflex.

Reflexes and sensation are otherwise normal. No pulse changes are noted in hyperabduc-

tion or on deep inspiration with the head turned to the right side (Adson’s manoeuvre).

In the right supraclavicular fossa a small hard lesion is palpable. The chest and abdomen

are normal.

You arrange a chest radiograph (Figure 13.1a,b).

(a)

(b)

Figure 13.1 (a) Chest and (b) anterior-posterior (AP) cervical spine radiographs.

Questions

• What differential diagnoses are you considering?

• What does the radiograph show?

• What imaging or investigation would you do next?

ANSWER 13

The differential diagnosis for this presentation is quite broad and can be narrowed down

in broad classes. The symptoms are predominantly neurological and primary neurological

causes such as spinal stenosis, tumour, cerebral infarct or multiple sclerosis or second-

ary causes including thoracic outlet syndrome affecting the brachial plexus, ulnar nerve

compression and carpal tunnel syndrome should be considered. The possible weakness

of elbow flexion and biceps reflex suggests a C5/C6 level lesion. There is less evidence

for a vascular cause such as Raynaud’s disease, vasculitis or vascular compression. Other

causes include trauma and soft tissue lesions such as a Pancoast tumour.

The radiograph shows bilateral cervical ribs. The mediastinum and lungs appear normal.

The right cervical rib has a pseudoarthrosis (false joint) in the mid portion that corre-

sponds with the hard palpable lesion in the supraclavicular fossa.

Although a vascular cause seems unlikely, an angiogram - selective imaging of ves-

sels - may be helpful to check for compression of the subclavian vessels. Arteries or

veins can be selectively studied by injection of contrast either by direct catheterization in

combination with fluoroscopy, or intravenous injection and selective timing of the com-

puted tomography (CT) scan. A catheter angiogram rather than a CT angiogram allows

the patient to be put in different positions to try to induce the intermittent symptoms. The

angiogram in Figure 13.2a proved to be normal. Given the predominantly neurological

symptoms, further imaging should concentrate on identifying the position of the underly-

ing lesion best done with magnetic resonance (MR) to examine soft tissue and nerve roots

at the cervical spine and brachial plexus (Figure 13.2b). MR is less sensitive for cortical

bone and a cervical spine radiograph for comparison is also helpful.

The patient’s symptoms are caused by the disc prolapse (demonstrated on MR) rather than

thoracic outlet syndrome due to the cervical ribs.

(a)

(b)

Figure 13.2 (a) Fluoroscopic arteriogram. The arrow shows displacement but no compression of

the right subclavian artery. (b) T2-weighted sagittal MR image showing degenerative changes at

C5/6 with disc protrusion into the canal (arrow) also resulting in nerve root compression.

KEY POINTS

• Thoracic outlet syndrome can be subdivided into neurological, arterial and venous

causes. The symptoms may help decide the most likely cause.

• Cervical ribs are a fairly common finding and often asymptomatic.

CASE 14: JAUNDICE FOLLOWING CHOLECYSTECTOMY

History

A 41-year-old woman attended hospital for an ultrasound appointment requested by her

general practitioner (GP). She had undergone a laparoscopic cholecystectomy 4 months

previously and had recovered well, but over the last 3 weeks she had been complaining

of increasing pain in the right upper quadrant and occasional itching. She denied any

weight loss or jaundice, and reported normal appearances to her stool and urine. She is

a non-drinker with no other notable medical history.

Examination

On examination she had slightly icteric sclera. She was comfortable at rest but had

scratch marks on her upper arms from recent itching. The cardiovascular and respiratory

examinations were normal, and her

abdomen was soft with slight ten-

derness of the right upper quadrant

on deep palpation. There was no

organomegaly.

Investigations showed a normal full

blood count and renal function, but

liver function showed an elevated

bilirubin and alkaline phosphatase

with normal transaminases and

albumin levels. Her amylase was

normal.

She was referred for an abdominal

ultrasound to assess her liver paren-

chyma (Figures 14.1 and 14.2).

Figure 14.1 Abdominal ultrasound.

Figure 14.2

Questions

• What does the ultrasound demonstrate?

• What procedure is performed in Figure 14.2?

• What is interventional radiology?

ANSWER 14

Figure 14.1 is a single ultrasound image of the left lobe of the liver obtained with a

curvilinear transducer (C5-2) in a longitudinal orientation. The liver appears of normal

echogenicity and echo texture with a smooth capsular contour. No focal lesion is seen on

this image. There are anechoic linear structures seen which extend to the periphery with

a maximal diameter of 4 mm, and colour Doppler assessment in Figure 14.2 demonstrates

no flow within them. This is in keeping with intrahepatic biliary duct dilatation, and the

remainder of the study did not demonstrate an obstructing lesion although the common

bile duct (CBD) was 7 mm in diameter, which is within normal limits for a patient post

cholecystectomy. The patient was referred for a liver magnetic resonance imaging (MRI)

scan for further characterization. The liver function tests of raised bilirubin and alkaline

phosphatase with normal transaminases and albumin suggest obstruction with normal

cellular and synthetic function.

Figure 14.3 is a coronal maximal intensity projection (MIP) image of the same patient

acquired from heavily T2-weighted sequences. It confirms moderate intrahepatic biliary

duct dilatation and also demonstrates a focal tapered stenosis at the level of the common

hepatic duct. There is no intraductal filling defect or stenosing soft tissue mass lesion, and

the CBD and pancreatic duct are of normal calibre. The appearances suggest a stricture

of the common hepatic duct which may be ischaemic, post inflammatory or neoplastic in

nature. Endoscopic retrograde cholangiopancreatography (ERCP) was advised to obtain

cytology brushings, attempt to correct the obstruction and decompress the intrahepatic

ducts, but a stent could not be inserted. The patient was therefore referred to the inter-

ventional radiology department for a percutaneous transhepatic cholangiogram (PTC).

The single image of the PTC (Figure 14.4) was acquired by opacifying the intrahepatic

ducts with radiographic contrast during a fluoroscopy procedure. The dilated ducts of

the left system were punctured under ultrasound guidance, and a guidewire was then

manipulated across the hilar stricture and down into the duodenum. A sheath (8F) was

inserted to stabilize the position, and contrast was injected through this to perform the

cholangiogram. A stent can be passed over the wire and placed across the stenosis to

relieve the obstruction and improve patient symptoms. This procedure is performed by

the interventional radiology department.

Interventional radiology (IR) is an expanding subspeciality of radiology that uses imaging

guidance and minimally invasive techniques to diagnose and treat a patient. A trained

radiologist uses their experience in ultrasound, computed tomography (CT) and fluoros-

copy to guide the passage of a needle or catheter to a site of interest and perform a task

that would otherwise be surgically difficult and involve significant morbidity in the form

of an open operation. Interventional radiology consultants can use the veins, arteries and

biliary ducts to access deep or distal lesions, vessels or organs, often leaving only a pin-

hole size scar at the site of puncture (often the groin) as a sign of recent treatment. This

allows tissue conservation, reduced morbidity and faster recovery for patients. The scope

of the speciality is too broad to be effectively covered in this answer, but the procedures

used include the following:

• Angiography: A vein or artery can be punctured with ultrasound guidance, and con-

trast is injected mapping the vessel anatomy under fluoroscopy. Stenoses and occlu-

sions can be characterized and an expandable balloon is used to improve blood flow.

This is termed ‘angioplasty’.

Figure 14.3 Coronal maximal intensity

projection image.

Figure 14.4 Percutaneous transhepatic

cholangiogram.

• Biopsy: Ultrasound (superficial lesions) and CT (complicated or deep lesions) can help

to guide a needle accurately to a lesion of interest for core biopsy and histological

characterization.

• Drainage: Inserting a drain can offer a conduit for decompression of infected collec-

tions or uncomfortable ascites. Optimal and accurate placement is obtained by imag-

ing guidance.

• Stenting: Expandable stents can be inserted into a vessel or duct to act as ‘scaffolding’

and can exert radial force to maintain patency in atherosclerosis or tumour stenosis.

• Line insertion: Patients on long-term therapy (e.g. dialysis, antibiotics, chemotherapy)

require definitive vascular access (e.g. Hickman line, portacath) to avoid the discom-

fort of recurrent peripheral cannulation and thrombophlebitis.

• Embolization: Instilling an embolic agent (coils, particles or glue) into a selectively

cannulated vessel can control active haemorrhage, prevent aneurismal rupture or

infarct a tumour (e.g. uterine fibroid). An adjunct to this is chemoembolization, where

a chemotherapy agent is instilled directly to a tumour and then the blood vessel is

embolized to cause tumour infarction.

CASE 15: INFANT WITH CLICKING HIPS

History

A 6-week-old female infant is brought by her mother as part of the 6-week check in gen-

eral practice. The baby was delivered at term by caesarian section due to a breech pres-

entation. Her maternal grandmother and aunt are known to have chronic hip problems.

Examination

On examination she moves both lower limbs normally. The hip creases appear a little

asymmetric. On Barlow’s manoeuvre (adduction of the hip with light pressure on the

knee) the right hip appears to pop posteriorly and then anteriorly on Ortolani’s man-

oeuvre (the hips and knees are flexed to 90 degrees and anterior pressure is applied to

the greater trochanters while using the thumbs to abduct the legs).

You expedite the hip ultrasound that has already been arranged due to the risk factors

(Figure 15.1).

angle

(a)

(b)

Figure 15.1 Left and right hip ultrasound images (coronal flexion view).

Questions

• Who gets hip ultrasound?

• What do the images in Figure 15.1 show?

• Is a radiograph helpful?

• What happens next?

ANSWER 15

Hip ultrasound is done on neonates and young infants (<6 months) to screen or check for

developmental dysplasia of the hip. Screening is done on infants with risk factors that

include family history, breech presentation, foot deformities or neuromuscular disorders.

Examination features that raise suspicion for hip abnormality include asymmetric groin

creases, a click on movement and a click or subluxation on provocation tests.

As with all ultrasound, gel is used to couple the ultrasound beam into the soft tissue and

allow movement of the probe without loss of image. The baby is placed in the lateral

position with the hip flexed and the probe is placed parallel to the ilium (bright line on

the left of the image) and the orientation optimized to produce a horizontal image like a

golf ball (stippled cartilage of the femoral head) on a tee (cup is the acetebulum, stalk is

the ilium). If the golf ball appears to be falling off the tee (upwards on the image), then

the femoral head is subluxed and the acetabular cup is shallow. This is all formalized by

measuring angles (indicated on the image). The alpha angle measures the acetabular roof

angle with the ilium and normally measures over 60 degrees. The beta angle assesses the

prominence of the labrum (cartilaginous flange around the acetabulum).

Figure 15.1 shows a normal left hip but a low alpha angle (53.5 degrees) on the right,

corresponding with a shallow acetabulum and hip instability. The ultrasound shows a lot

of soft tissue detail, including the unossified cartilage as well as the bone, although the

anterior bone edge blocks the beam and no deeper structure is seen. Plain radiographs

complement this view by demonstrating the bone structure but with very poor soft tissue

detail. Ultrasound is the investigation of choice in infants with unossified femoral heads

but as the ossification centre develops and blocks the ultrasound from about 6 months

onwards, radiographs are more useful. Figure 15.2 shows the hip radiograph at 4 months.

The aim is to diagnose a hip abnormality as soon as possible to minimize the degree of

intervention required to fix the problem. Treatment ranges from observing (if very mild

and picked up on a neonatal scan) to braces or surgical intervention.

Figure 15.2 Radiograph at 4 months

with right hip subluxation and a

shallow right acetabulum (relative

to Hilgenreiner’s line drawn on the

radiograph).

KEY POINTS

• Ultrasound is the method of choice for examining infant hips.

• Hip screening in infants with family history or breech presentation occurs at 4-6 weeks.

CASE 16: PAINFUL WRIST AFTER FALLING

History

A 13-year-old girl presents to the accident and emergency department with a painful right

wrist after falling while roller skating. She fell backwards with her arm outstretched. Her

wrist appears deformed, but she tells you that although it hurts, the wrist has had that

appearance for a long time and that it was investigated at another hospital many years ago.

She gives a family history of bone problems but is otherwise well with no medical problems.

Examination

On the volar aspect of the right forearm just proximal to the wrist there is a firm swelling

that extends laterally. There is some associated tenderness but no malalignment of the

wrist or hand. There is normal movement, pulses and sensation. The chest and abdomen

are normal. Given the history you also briefly examine the arms and spine that appear

normal and the legs. The bone around the knees is prominent, with an asymptomatic

bony nodule over the lateral aspect of the proximal right tibia.

You arrange radiographs of the arm (Figure 16.1a,b).

(a)

(b)

Figure 16.1 Anterior-posterior (AP) and lateral radiographs.

Questions

• What do the radiographs show?

• Can you name some differential diagnoses?

• What other imaging should be obtained?

ANSWER 16

The radiographs show a lobulated expansile lesion arising from the cortical bone of the

radial metaphysis and extending proximally. The bone is well delineated with a narrow

zone of transition, an appearance suggesting the lesion is benign. No fracture is seen.

The appearance is in keeping with an exostosis, also known as an osteochondroma, that

results from dysplasia of the growth plate. This may be solitary or multiple in a condition

known as multiple hereditary exostosis (or diaphyseal aclasis), or rarely as part of various

syndromes such as Turner’s syndrome or tuberous sclerosis.

Rather than take more images of the arm, the best course of action would be to obtain

previous images. Picture archiving and communication system (PACS) is the digital system

developed to manage the images prima-

rily produced in hospital radiology depart-

ments. In the last decade it has almost

entirely replaced film-based archives with

the advantages of rapid search and com-

parison, remote and web-based access and

integration into other hospital information

systems. In this patient, a previous skeletal

image on PACS (Figure 16.2) suggests the

diagnosis of multiple hereditary exostosis.

Multiple hereditary exostosis is inherited

as an autosomal dominant trait, with an

incidence of about 1 in 50 000. Children are

diagnosed on average around 3 years old.

As seen in this case, bony growths (exos-

toses) arise from the metaphyses, point

away from epiphysis, and extend down

the diaphysis during growth. They increase

in size and number with age, arising in

several characteristic sites. Over

90 per

cent of cases are at the distal and proxi-

mal tibia, proximal femur and proximal

Figure 16.2 AP radiograph of both legs

humerus. Ribs, scapula, radius, ulna, ilium

showing large right proximal and distal lateral

and phalanges are also common sites.

tibial exostoses and bilateral proximal medial

tibial exostoses (see arrows).

Clinical complications include trauma and

fractures, particularly at exposed positions

at the wrist and knees. The exostosis may exert pressure on surrounding soft tissue and

cause neurovascular compromise. There can be inequality in limb length or short stature.

In a small proportion of patients (1-2 per cent) at a later age (>21) an exostosis undergoes

sarcomatous transformation into a chondrosarcoma. This is more likely in exostoses of

the pelvis, scapula, proximal humerus, proximal femur and spine, and may be associated

with a change in size or onset of pain.

KEY POINTS

• Exostoses can be solitary or multiple and develop from the metaphysis while the

growth plate is open.

• Exostoses can cause symptoms. In older symptomatic patients, malignant

transformation should be considered although it is uncommon.

CASE 17: CONSTIPATION IN WOMAN WITH OVARIAN TUMOUR

History

A 78-year-old woman presents to the oncology clinic with a 1 week history of right

upper quadrant and epigastric tenderness and constipation for 3 days. She has a history

of metastatic ovarian cancer treated with abdominal hysterectomy, oophorectomy and

omentectomy for peritoneal disease 15 months ago. She has also had chemotherapy. On

her last scan she was noted to have lung nodules, mediastinal and mesenteric lymph node

enlargement that appeared stable and a new caecal metastatic deposit.

Examination

On examination, she is not acutely unwell. Her observations are normal. The chest and

heart sound normal. The upper abdomen is tender and there is a palpable fullness or mass

below the right costophrenic margin.

You assess an abdominal radiograph (Figure 17.1) during clinic and decide to admit the

patient for assessment and a computed tomography (CT) scan.

Figure 17.1 Abdominal radiograph.

Questions

• What is the likely cause of her pain?

• What does the radiograph show?

• What appearance do bowel contents have?

ANSWER 17

Based on the history of cancer and surgery, the patient is at risk of bowel obstruction

secondary to adhesions associated with surgery or tumour infiltration. Metastatic ovarian

carcinoma frequently metastasizes through the peritoneal space, seeding deposits onto

the omentum (removed in this patient’s case) and mesentery. Liver metastases are also

possible, causing pain from stretching the liver capsule, biliary obstruction or ascites.

Other common causes that are less likely in this case are cholecystitis and appendicitis.

The radiograph shows a large volume of faeces in the pelvis within large bowel or rectum

and gas-filled empty bowel loops on the left side of the abdomen. There is a paucity of

bowel gas on the right together with impression of a large soft tissue region extending

throughout the right side of the abdomen. Small bowel can be distinguished from large

by its central position and a fold pattern likened to a coiled spring (valvulae conniventes)

less than 3 cm in normal diameter. Large bowel tends to frame the abdomen with haus-

tral folds that are widely spaced and not circumferential (i.e. they do not cross the whole

diameter of the visible bowel).

The patient’s CT (Figure 17.2) shows a large right upper quadrant mass, probably a meta-

static deposit, displacing empty transverse colon to the left and partially obstructing the

caecum that is distended by faeces. Gallstones are also seen; these are not apparent on

the plain radiograph.

The colon receives the sterile dilute

product of digestion and then pro-

ceeds to remove a large propor-

tion of the fluid content as well

Gallstone

as employing microbial digestion

(fermentation) to extract various

products not produced in small

bowel digestion, such as vitamin K.

Mass

As a result, faeces take on a more

solid appearance as they move

round the colon. In addition, the

microbial activity produces gas and

the stool has a characteristic foamy

appearance. Stomach contents also

Caecum

have a similar appearance with

food mixed with fluid and air.

Small bowel tends to be predomi-

nantly homogeneously fluid filled

in appearance although with a

Figure 17.2 Reconstructed coronal CT slice of the

small amount of gas that increases

abdomen and pelvis.

if there is obstruction.

KEY POINTS

• The distribution of stool tends to be of more significance than its appearance.

• Constipation may be indicated by a large volume of stool throughout the bowel,

a rather solid appearance to the stool in the rectum or impacted faeces above an

obstruction.

• Radiographs are rarely indicated for constipation unless obstruction is suspected.

CASE 18: THIRTY-YEAR-OLD MAN WITH HEADACHE

History

A 30-year-old man presents to you with a chronic history of headache that has worsened

significantly in the last week. Investigations for the same problem 9 months ago ruled

out sinus disease. He is concerned that this may be due to a brain tumour. Several rela-

tives have died of various types of cancer. There is no history of definite head trauma,

although he has had various sporting injuries. There is no other history of significant

illness. On careful questioning the headache is reported to be present on waking and

worsens on coughing.

Examination

On examination he is well. His observations are normal. There is papilloedema on exami-

nation of the eyes but no focal neurology is demonstrated. Examination is otherwise

normal.

You arrange a computed tomography (CT) scan of the head.

(a)

(b)

Figure 18.1 Axial CT image of the brain at the level of (a) the third ventricle and (b) the fourth

ventricle.

Questions

• Headache is a common problem. What red flag symptoms help to decide on investiga-

tions?

• What does the CT show?

• What would you do next?

ANSWER 18

Headache is a common problem, often assessed in general practice and often associated

with tumours by patients. The annual incidence of brain tumours is about 10 per 100 000

per year whereas up to 4000 per 100 000 GP consultations are for headache, so some

discrimination has to be used to avoid imaging every patient.

If you see papilloedema then red flags are not required, urgent investigation is manda-

tory, after checking your records for previous investigation - very occasionally it is idio-

pathic and chronic. More commonly, fundoscopy is not performed well enough to see

changes. Other red flags include:

• systemic symptoms (e.g. neck stiffness) or secondary risk factors (e.g. cancer, HIV,

thrombosis);

• neurological symptoms or signs;

• onset (e.g. thunderclap headache);

• new progressive or unilateral headache in older patients (consider temporal arteritis);

• previous headache history changing pattern;

• triggered headache (e.g. cough, sneeze, straining).

The CT shows a large midline mass in the region of the pineal gland extending into

the subtentorial region, displacing the cerebellar vermis and hemispheres inferiorly and

compressing the aqueduct and fourth ventricle. There is dilatation of the lateral and third

ventricles but undilated fourth ventricle and basal cisterns in keeping with obstructive

hydrocephalus.

The next step is to characterize the midline lesion using magnetic resonance (MR) (Figure

18.2). This confirms hydrocephalus caused by a pineal fossa or tectal plate mass with

evidence of cerebrospinal fluid (CSF) in the periventricular tissue, suggesting the obstruc-

tion is acute. The lesion may be a pineoblastoma.

Mass

3rd ventricle

4th ventricle

(a)

(b)

Figure 18.2 (a) Coronal and (b) midline sagittal T1 MR sequence images after gadolinium

contrast.

Hydrocephalus appears on scans as dilated CSF spaces and can be caused by obstruction,

as in this case. Communicating hydrocephalus occurs in the absence of obstruction due

to overproduction of CSF (e.g. tumour), defective absorption of CSF (most common, e.g.

after haemorrhage) or venous drainage insufficiency. Normal pressure hydrocephalus

occurs in older patients characterized by dilatation but no elevation of CSF pressure at

lumbar puncture and may be caused by intermittent intracranial hypertension.

This patient requires referral to a neurosurgical centre as the hydrocephalus requires acute

treatment with a shunt, as well as treatment planning for the underlying tumour.

KEY POINTS

• Headache is a common symptom and is only rarely caused by a brain tumour.

• Hydrocephalus can be acute or chronic, communicating or obstructive.

• CT is the initial investigation for acute neurological problems to check for

haemorrhage, hydrocephalus and presence of mass lesions.

CASE 19: PERSISTENT COUGH

History

A 65-year-old woman with a persistent cough comes to see you in general practice. She

says that the cough has been present for months but that it has got worse in the last

week with associated coryzal symptoms. There is no history of haemoptysis, chest pain

or weight loss. She does not have asthma and is on medication for high blood pressure

and high cholesterol. She has a 30 pack-year smoking history, although she gave up

2 years ago.

Examination

There is no abnormality on examination of the respiratory system. Temperature and pulse

are normal; her blood pressure is 136/82. There is no significant neck lymphadenopathy

or tonsillar enlargement.

You consider the diagnosis of an acute upper respiratory tract infection with a back-

ground persistent cough. The cough has not been investigated before and you explain to

the patient that you will arrange a chest X-ray (Figure 19.1) but that antibiotics do not

seem appropriate currently.

Figure 19.1 Posterior-anterior chest radiograph.

Questions

• What does the radiograph show?

• What are the most likely diagnoses?

• What is the next step?

ANSWER 19

The radiograph shows a single spiculated mass in the right mid zone. No significant hilar

or mediastinal widening is seen.

The differential diagnosis for a single pulmonary mass includes primary or secondary

carcinoma, hamartoma (especially if fat and calcification can be identified), pneumonia

or arteriovenous malformation. The patient’s age, smoking history and chronic cough are

red flags for considering carcinoma.

The next step is rapid referral of the patient to chest clinic with a preceding staging com-

puted tomography (CT) scan. Most hospitals have a streamlined process for the radiology

department to flag up the patient to the relevant specialist clinic if cancer is suspected,

in anticipation of an urgent general practitioner (GP) referral.

The diagnosis of non-small cell lung carcinoma and stage of disease was confirmed by

biopsy and positron emission tomography (PET) scan that confirmed T2a (<5 cm) N0 M0

(no affected lymph nodes or metastases) staging. The tumour was removed with the right

upper lobe (lobectomy).

The post-lobectomy radiograph (Figure 19.2a) shows signs of loss of right lung volume

with elevation of the right hemidiaphragm and hilum but no significant right rib space

narrowing.

(a)

(b)

Figure 19.2 (a) Post- and (b) pre-operative chest radiographs with the lesion marked with an

arrow.

GPs have access to many imaging modalities at their local hospital, although plain

radiographs and ultrasound are the most used. They receive copies of the image reports,

typically within a week, but are not able to view the images. The Royal College of

Radiologists has produced referral guidelines.¹

Chronic cough is a common GP presentation. The British Thoracic Society has produced

guidelines on how to manage chronic cough,² a chest radiograph being one of the first

steps. Subsequent imaging depends on the diagnosis and whether imaging is likely to be

helpful in management.

CASE 20: CHEST PAIN AND DYSPNOEA

History

This 66-year-old woman was referred to the accident and emergency department by her

general practitioner (GP) with a 2 week history of dyspnoea, cough and fever that has

been worsening and an unclear history of new onset pleuritic chest pain. There is also a

history of a chronic pressure sore, type 2 diabetes and high blood pressure treated with

appropriate medication. The GP had treated her for a few days with antibiotics initially

with little effect.

Examination

Her temperature is 39.3°C, pulse 104/minute, oxygen saturation 89 per cent breathing air

and there appears to be a right ventricular heave. There are coarse lung sounds in the

right upper zone posteriorly. The abdomen is soft and non-tender. The left hip is painful

but demonstrates normal range of movement and weight bearing. There is a mild degree

of peripheral sensory neuropathy but the legs are otherwise normal.

You arrange tests including a chest radiograph (Figure 20.1).

Figure 20.1 Chest radiograph.

Questions

• What does the chest radiograph show?

• What are possible causes of the abnormality?

ANSWER 20

There is one and possibly a second circular cavitating lesion in the right upper zone that

contains an air-fluid level and has a thin wall superiorly. There is bilateral apical thick-

ening. The hila appear normal and the heart is not enlarged. A displaced old fracture of

the left clavicle is noted.

There are multiple causes of cavities in the lung and features that help decide on likely

differential diagnoses include the clinical context, number of lesions, wall thickness,

appearance of contents (if any), position and presence of enlarged lymph nodes.

In terms of categories, cavities may form due to:

• infection, such as Staphylococcus (frequently multiple), Klebsiella, tuberculosis (fre-

quently associated with fibrosis) and aspiration (these cavities are usually thick walled

and may contain fluid levels);

• neoplasm, such as bronchogenic carcinoma (particularly squamous cell carcinoma,

SCC), metastases such as SCC, colon and sarcoma, Hodgkin’s disease (with lymphad-

enopathy), often with thick walls;

• vascular infarction that may cavitate or become infected and cavitate;

• trauma, either the result of a haematoma or formation of a traumatic lung cyst;

• abnormal lung - infected emphysematous bulla;

• cavitating nodular vasculitic disease such as Wegener’s granulomatosis, rheumatoid

arthritis and occasionally granulomatous disease such as sarcoidosis, which all fre-

quently have multiple cavities.

Given the patient’s tachycardia, ventricular heave and hypoxia it is also important to

consider cardiac causes and possible pulmonary embolism. A computed tomography (CT)

pulmonary angiogram was arranged (Figure 20.2a,b).

(a)

(b)

Figure 20.2 CT pulmonary angiogram showing a right lower lobe fluid-filled cavity (a) and, on

the slice just inferior (b), a pulmonary embolus in the right lower lobe pulmonary artery (white

arrow).

CASE 21: YOUNG MAN WITH NECK SWELLING

History

This 17-year-old man presents to his GP with a swelling at the base of his neck that he

noticed recently after swimming. He also complains of tiredness, some loss of appetite

and night sweats developing over the last 4-6 weeks. There is no other medical history.

He has not travelled outside Europe and is not aware of recent exposure to any infec-

tious disease.

Examination

On examination he has normal weight and does not appear unwell. He has normal obser-

vations. There is a palpable mass in the left supraclavicular fossa and prominent nodes

in the neck and axillae. The chest is clear. The abdomen is soft and not tender. You take

blood tests and arrange for a chest radiograph (Figure 21.1).

Figure 21.1 Chest radiograph.

Questions

• What abnormalities are seen on the chest radiograph?

• What differential diagnosis would you consider?

• What other investigations would you consider for diagnosis?

ANSWER 21

The chest radiograph shows marked enlargement of the hila and mediastinum with mul-

tiple rounded masses. Multiple soft tissue masses are also noted in both lungs. The heart

and bones appear normal.

The differential diagnosis to be considered is that of bilateral hilar and mediastinal

enlargement with multiple lung masses. The hilar masses are lymph nodes and massively

enlarged. The mediastinal masses are likely to be in the anterior or middle mediastinum as

the thoracic spine and aortic outlines are clearly seen. At 17, the patient is young enough

to consider congenital causes but the recent symptoms and the widespread appearance

are suggestive of an acquired disorder. The differential could include neoplastic causes

such as lymphoma, leukaemia, germ cell tumour, metastases from sarcoma or possibly a

Wilms’ tumour, inflammatory lymphadenopathy from tuberculosis, sarcoidosis, histoplas-

mosis or, less likely, a congenital cause such as lymphatic malformation. The most likely

diagnosis is Hodgkin’s lymphoma.

Cross-sectional computed tomography (CT) imaging is required (Figure 21.2), also below

the diaphragm to assess and stage the extent of disease. A tissue sample is also required

and this can be obtained by percutaneous biopsy of an enlarged superficial lymph node

(e.g. in the neck) or by endobronchial ultrasound-guided aspiration from a hilar lymph

node. Washings can also be taken to rule out tuberculosis.

(a)

(b)

Figure 21.2 Coronal computed tomography (CT) slices through (a) the thorax with arrows

showing mediastinal, hilar and pulmonary lymphadenopathy; (b) the abdomen showing

enlarged pancreatosplenic lymph nodes and a low attenuation lesion in the spleen.

Some nodes have lower attenuation centrally, suggesting necrosis. These finding are sig-

nificant for the staging and treatment planning. Hodgkin’s lymphoma responds well to

chemo- and radiotherapy with good long-term survival, and the long-term side effects of

treatment must be considered when planning treatment regimes.

CASE 22: COLLAPSE AND POSSIBLE SEIZURE

History

A 75-year-old woman is brought into the accident and emergency department following

a collapse at home. She has no recollection of the event and appears very confused. Her

husband found her on the floor and is worried that she may have hit her head on some

furniture. The husband gives a history of his wife being ‘under the weather’ and ‘not quite

herself’ for several months, although he is unable to explain more specifically. She has

otherwise been fit and well and takes medication for blood pressure and for osteoporosis

prophylaxis.

Examination

On examination, routine observations are normal. Her Glasgow Coma Score (GCS) is 15

and Mini Mental Test score 6/10. She has mild left-sided limb weakness that appears to

be resolving. The chest, cardiovascular and abdominal examination is normal.

You arrange tests including an urgent computed tomography (CT) scan of the head

(Figure 22.1), as called for by the National Institute for Health and Clinical Excellence

(NICE) guidelines on head injury criteria, including the patient’s age and amnesia.

Figure 22.1 Axial non-contrast CT scan through the

brain at the level of the quadrigeminal cistern.

Questions

• What does the CT show?

• What would you do next?

ANSWER 22

The CT shows a large lobulated mass with homogeneously increased attenuation in the

right parasagittal frontal lobe. There is mass effect with effacement of the frontal horn

of the right lateral ventricle and 1 cm shift of the midline to the left. There is minimal

surrounding vasogenic oedema. There is no intracranial haemorrhage or infarct. The basal

cisterns are patent.

When considering an intracranial mass, the first step is to decide if the mass arises within

the brain (intra-axial), ventricles or cisterns, or from the adjacent structures (extra-axial)

such as the meninges or the bone. More imaging using contrast-enhanced magnetic reso-

nance (MR) (or contrast CT if this is not possible) is also done, as this is more sensitive

to possible other lesions as well as giving more information about the tumour structure

and the surrounding brain (Figure 22.2).

(a)

(b)

Figure 22.2 Gadolinium contrast-enhanced T1-weighted images of the brain showing a

uniformly enhancing lobulated mass in the right frontal lobe.

The MR shows that the tumour grows from a broad segment of the meninges and appears

to be growing along the falx at its edge (see arrow, Figure 22.2b), a so-called dural tail,

that is quite characteristic for a meningioma or metastasis (particularly breast). The

absence of other lesions and no history of a tumour elsewhere makes a metastasis less

likely although it is important to look. Meningiomas frequently have associated calcifi-

cation and adjacent bone change. The differential also includes intra-axial tumours and

lymphoma, although appearance and position make this less likely.

Meningiomas occur intracranially and within the spinal canal arising from the arachnoid

layer. They are common, second only to glioblastoma in frequency. The parasagittal

position is the most common (33-50 per cent), although other common sites are near the

vertex or by the lesser wing of sphenoid or petrous ridge. Ninety per cent are benign but

because they grow slowly they can eventually have a space-occupying effect, become

ANSWER 23

Figure 23.1 shows the abdomen. Two tubes passing over the umbilicus are umbilical

artery and vein catheters. They can be distinguished by their course, the umbilical artery

catheter passes inferiorly to join the internal iliac artery before passing superiorly. The

tip should lie between T6 and T9 vertebral level to avoid major branches. The umbili-

cal venous catheter passes superiorly to the left portal vein, passing through the ductus

venosus into the inferior vena cava (IVC). The tip should lie within the upper IVC or at

the border with the right atrium. In Figure 23.2, the tip of a nasogastric (NG) tube is

seen overlying the stomach. Aspiration and radiographs are typically used to check the

position.

The appearances on the first image (Figure 23.1) are non-specific but gas-filled small and

large bowel in a symptomatic premature infant should ring alarm bells.

The second image (Figure 23.2) shows dilatation of the bowel (greater than the width of

the L1 vertebral body). Bowel wall gas lucencies (pneumatosis intestinalis), particularly

in the right lower quadrant and portal venous gas (lucency over the liver) is seen. No

evidence of perforation is seen to warrant immediate surgical intervention.

Subsequent images (Figure 23.3) showed further distension and free gas outside the

bowel.

(a)

(b)

Figure 23.3 (a) Anterior-posterior (AP) and (b) lateral abdominal views with the patient supine

showing free gas (arrows) above the liver and around the bowel loops, indicating perforation.

The main differential diagnosis is necrotizing enterocolitis and other forms of sepsis.

Other differentials include Hirschprung’s disease (aganglionic distal colon/rectum), bowel

obstruction (such as small bowel atresia, meconium ileus, meconium plug) and ischaemia,

particularly in congenital cardiac disease.

Initial management is usually conservative including antibiotics and repeated imaging.

Surgery may be required for perforation or failure of medical management.

CASE 24: YOUNG CHILD WITH PAINFUL ARM

History

This 1-year-old girl has been in the paediatric department for a few weeks for treatment

of streptococcal sepsis after chickenpox. Around the time of admission the child had

swelling over the left upper arm but no abnormality was seen on plain radiograph and

there was no collection on ultrasound. After treatment on the paediatric intensive care

ward she improved but then started to get intermittent fevers and worsening of the left

upper arm swelling.

Examination

The child is irritable and off her feeds. There is tachycardia and pyrexia. Cardiovascular

and respiratory examinations are normal. The abdomen is soft and non-tender. Her left

arm is not moving, red and swollen over the upper aspect. She complains when you

handle or move the arm.

You arrange a plain radiograph and compare it with the previous image (Figure 24.1a,b).

(a)

(b)

Figure 24.1 (a) Initial radiograph of left elbow. (b) Radiograph taken 14 days later.

Questions

• Describe the changes seen.

• What other imaging would you arrange?

ANSWER 24

The first radiograph (Figure 24.1a) is essentially normal (there may be some soft tissue

swelling). The second radiograph (14 days later) (Figure 24.1b) shows thick periosteal

reaction along the shaft of the humerus. Patchy lucency is seen within the distal humerus.

The appearance is consistent with an aggressive process. Given the acute onset and

sepsis, this is likely to be acute osteomyelitis that is an inflammation of bone caused by

an infecting organism. The differential for periosteal reaction in an infant could include

infiltrative tumour such as leukaemia or neuroblastoma, (non-accidental) trauma, prosta-

glandin therapy or vitamin deficiency such as rickets (not uncommon) and scurvy (rare).

Osteomyelitis has a bimodal distribution. In children it typically occurs by haemato-

genous spread with insidious onset. Typical bacteria are Staphylococcus aureus, group A

Streptococcus (in this case), Haemophilus influenzae and Enterobacter species. Patients

with sickle cell disease are particularly at risk of S. aureus and Salmonella species. The

bacteria pass into the metaphysis of the most rapidly growing tubular bones via nutri-

ent vessels where they lodge and cause inflammation, vascular congestion and increased

pressure. There may also be some thrombosis. This is followed by a suppurative phase

where pus forms subperiosteal abscesses. Increased pressure and thrombosis compromises

the blood supply causing bone necrosis and sequestrum formation (fragments of necrotic

bone) over a period of days. A layer of new bone, or an involucrum, forms around the

raised periosteum. With treatment there is a resolution phase with remodelling of bone.

A skin sinus can form in the absence of treatment or as a complication. Other complica-

tions in children arise due to damage of the growth plate with deformity or shortening of

the developing bone. Haematologically spread osteomyelitis in adults is typically centred

in a vertebra.

Direct osteomyelitis is associated with traumatic inoculation, more focal and more typi-

cal in adults, particularly those who are at increased risk due to peripheral neuropathy

and immune compromise such as diabetic patients. Typical bacteria are S. aureus,

Enterobacter species and Pseudomonas species. The development is much the same as

described but more focal.

Other imaging that is helpful is a three-phase bone scan that images the whole skeleton

and identifies further sites of disease. A magnetic resonance (MR) scan is useful to con-

firm the diagnosis and examine the soft tissues and bone marrow for abscess formation

and complications.

Figure

24.2a,b shows subsequent plain radiographs of the sequestrum phase and

resolution.

CASE 25: ACUTE EPIGASTRIC PAIN

History

This 57-year-old woman presented to the accident and emergency department with sud-

den onset of epigastric pain with vomiting and retching. There is a background history

of grumbling epigastric discomfort with loss of appetite and weight but no bowel distur-

bance. There is no other medical history of note.

Examination

She looks unwell with mild pyrexia and dehydration. The pulse is 96/minute and regular,

blood pressure is 122/80 lying and 104/72 standing. The chest examination is otherwise

normal. Abdominal examination shows mild distension with no significant scars but it is

rigid to palpitation, dull to percussion and very reduced bowel sounds are heard.

Abdominal and erect chest radiographs are obtained (Figure 25.1).

(a)

(b)

Figure 25.1 (a) Abdominal and (b) chest radiographs.

Questions

• What abnormality is present on the X-ray?

• What is your differential diagnosis?

• What further imaging would you like to do?

ANSWER 25

This is a case of acute abdomen. The first priority is to resuscitate and stabilize the patient

and as the patient is middle aged and relatively fit, she may be compensating quite well.

The abdominal X-ray shows undilated small and large bowel. No classic signs of free gas

outside the bowel wall (Rigler’s sign), triangular gas pockets or gas outlining the falciform

ligament are seen on the abdominal radiograph.

A chest X-ray is part of the investigation of acute abdomen and is obtained after about

5 minutes with the patient sitting as upright as possible. This allows any free intra-

abdominal gas to rise, giving the characteristic free gas under the diaphragm sign. This

chest radiograph shows free gas below the diaphragm (pneumoperitoneum). Appearances

may be deceptive and gas within an organ may look like a perforation. The right upper

quadrant is a good place to look as the liver normally abuts the diaphragm and any

gas will be obvious. Occasionally the bowel will occupy this space, a condition called

Chiladiti’s syndrome. Look for characteristic bowel wall folds.

Differential diagnosis for free gas under the diaphragm includes:

• iatrogenic causes - normal appearance after a surgical or laparoscopic procedure or

perforation from a surgical anastomosis or after endoscopy;

• perforation due to gastroinstestinal tract disease - gastric/duodenal ulcer, appendix

or diverticular perforation, obstruction (e.g. neoplasm) or specific paediatric disorders

and inflammatory bowel disease;

• conditions that mimic free gas - pseudopneumoperitoneum, such as distended bowel

loops, Chiladiti’s syndrome, diaphragmatic hernia, oeosphageal diverticulum and sub-

phrenic abscess.

A contrast computed tomography (CT) is typically done provided the patient is stable, as

the additional anatomical information may help locate the source of perforation (Figure

25.2).

Mass

Ulcer

Free gas

Figure 25.2 Sagittal reconstruction CT slice of the abdomen, showing free gas anterior to the

stomach suggesting a perforated gastric ulcer and possible gastric mass. This is useful for the

surgeon to know as tissue diagnosis is required and surgical planning may change.

ANSWER 26

The radiograph shows an abnormal but well-defined right heart border. This may reflect

cardiac enlargement or a separate soft tissue mass. In general, the position of a soft tissue

mass may be indicated by the loss of definition of the edge of adjacent structures - the

silhouette sign. In this case the right heart border is abnormal, suggesting a mass adjacent

to the right atrium of the heart obscuring the normal air-tissue interface. The differen-

tial diagnosis therefore includes anterior and middle mediastinal or lung masses such as

pericardial cyst, lipoma, fat pad, bronchogenic cyst, sequestration, massive lymphaden-

opathy, diaphragmatic hernia, ventricular aneurysm or right atrial enlargement.

A computed tomography (CT) scan is the next step in imaging (Figure 26.2). This not

only localizes the abnormality but also displays the soft tissue attenuation (measured

in Hounsfield units, HU), which allows distinction between fat (e.g. in a fat pad or

lipoma - typically negative HU), water-like fluid (HU <10) in a cyst, soft tissue and

contrast (>100 HU) in, for example, a ventricular aneurysm. In this case there is a fluid

attenuation mass adjacent to the heart, which otherwise appears normal, consistent with

a pericardial cyst. There is also a small area of adjacent right upper lung lobe collapse

(atelectasis).

Pericardial cysts are congenital malformations that are attached to the parietal pericar-

dium, but do not communicate with the pericardial space. If there is communication with

the pericardial space, the structure is termed a pericardial diverticulum. They are usu-

ally found incidentally in asymptomatic

patients. The most frequent location is in

the right cardiophrenic angle, but they can

be found in the left cardiophrenic angle,

anterior mediastinum or middle media-

stinum. The vast majority are unilocular

and they usually range in size between

3 and 8 cm. Because they are soft, they

may change shape with position. Rarely,

they may cause symptoms due to compres-

sion of surrounding structures and require

surgical removal.

Bronchogenic cysts arise out of the tracheo-

bronchial tree as a congenital malform-

ation, typically pericarinal but also para-

tracheal, oesophageal, retrocardiac and

pulmonary in location. They are usually

asymptomatic but may cause stridor, com-

pression or become infected.

Figure 26.2 Reconstructed coronal CT slice

through the thorax.

KEY POINTS

• Pericardial cysts are occasionally incidental, asymptomatic findings on chest X-ray.

• They abut the heart, resulting in a silhouette sign, and may be diagnosed on CT if they

have classic cystic appearance.

CASE 27: YOUNG WOMAN WITH SHORTNESS OF BREATH

AND CHEST PAIN

History

This 37-year-old woman presents to the accident and emergency department after refer-

ral from her general practitioner

(GP) complaining of increasing breathlessness and

intermittent right-sided chest pain. The symptoms have come on over 2-3 weeks without

associated fever or significant cough. There is a medical history of pelvic pain that is

undergoing investigation for suspected endometriosis. She is otherwise well, a non-

smoker and taking no medication.

Examination

The right hemithorax is dull to percussion with reduced breath sounds throughout. The

left lung and heart sound normal. The abdomen is soft and there is tenderness to palpa-

tion diffusely over both iliac fossae.

You arrange some tests including a chest radiograph (Figure 27.1).

Figure 27.1 Chest radiograph.

Questions

• What is the main abnormality and what effect is it having on the normal anatomy?

• What is the differential diagnosis?

• What is the appropriate management?

ANSWER 27

There is uniform opacification of most of the right hemithorax. The right hemidiaphragm

and heart border are not seen. There is displacement of the heart and trachea to the left.

Some residual aerated right lung is noted, probably the apices of the right upper and lower

lobes. The left lung and heart are normal in appearance. No bone abnormality is seen.

We are looking for causes of opacification of a hemithorax. This can be within the lung,

mediastinum or pleural space and may involve consolidation, soft tissue or fluid. The posi-

tion of the mediastinum gives a clue as it is displaced away from the opacity even though

the lung only appears partially aerated. This suggests a differential of pleural fluid or soft

tissue, such as from a diaphragmatic hernia. Other causes such as consolidation, lung col-

lapse, tumours (such as mesothelioma) or congenital agenesis or hypoplasia tend either not

to displace or to displace the mediastinum

towards the opacity. The appearance with

smooth edges and some thickening of the

horizontal fissure suggests pleural effusion.

Effusions can be transudates

(protein

<30 g/L; e.g. in cardiac failure), exudates

(>30 g/L; e.g. in infection, malignancy,

pulmonary infarction), haemorrhagic (e.g.

trauma, carcinoma) or chylous (e.g. due

to obstructed thoracic duct caused by

trauma, malignancy or parasites). Systemic

diseases often cause bilateral effusions but

can be unilateral.

(a)

To investigate this further, cross-sectional

imaging to determine the underlying cause

may be done. Computed tomography (CT)

is not typically sensitive to the type of

effusion. The effusion may also be drained,

particularly if the patient is symptomatic,

and a sample of fluid may help to decide

on the cause. This is typically done with

ultrasound guidance (Figure 27.2a), often

using a Seldinger technique with a needle

to insert a guidewire over which a drain

tube is inserted. Thoracoscopy may be per-

formed to look into the pleural space and

allows biopsy of any abnormal pleural tis-

(b)

sue. Figure 27.2b shows the result of drain-

age. The effusion in this case was stained

Figure 27.2 (a) Ultrasound of the right lung

with old blood and eventually shown to be

base; (b) anterior-posterior (AP) radiograph

caused by an endometriosis deposit.

showing a right basal chest drain and partial

drainage of the effusion.

KEY POINTS

• There are multiple causes of thoracic opacification and noting the effect on the

mediastinum and anatomy helps to narrow down the possible causes.

• Consider pleural effusions in terms of transudate, exudates, blood and chyle.

CASE 28: CHEST DISCOMFORT AND DYSPNOEA

History

A 68-year-old man on treatment for non-Hodgkin’s lymphoma presents to the accident

and emergency department with mild chest discomfort, worse on lying flat and eased by

leaning forward. It has been getting slowly worse over the last few weeks. Now he gets

dizzy on standing, rapidly breathless on exertion and has noticed some bilateral ankle

swelling over the last week. He does not have a significant past cardiac or respiratory

history.

Examination

On examination his blood pressure is 144/88, pulse 94/minute and respiratory rate

22/minute. The JVP is a little raised and fine crackles are heard at both lung bases. The

heart sounds are difficult to hear but otherwise regular. The abdomen is soft and there

is moderate left flank tenderness to deep palpation. The electrocardiogram (ECG) shows

small QRS complexes and T wave inversion.

You organize a chest radiograph as well as blood tests (Figure 28.1).

Figure 28.1 Posterior-anterior (PA) chest

radiograph.

Questions

• What abnormalities are seen?

• What others symptoms or signs might you find?

• What other tests would you do?

ANSWER 28

The heart is enlarged. The hilar vessels are not enlarged. There is some blunting of the

costophrenic angles but no lung abnormality is seen.

The heart size is usually estimated by measuring the cardiothoracic ratio (CTR, maxi-

mum cardiac width/maximum inner thoracic width) on a PA projection radiograph with

adequate inspiration (6 ribs seen anteriorly, 10 posteriorly). Beware anterior-posterior

(AP) projections and poor inspiration as this will artificially increase the size of the heart.

Typically in adults a CTR ratio >0.5 suggests cardiomegaly.

In addition to the CTR, the heart shape may indicate an underlying cause such as valve

disease or a shunt. Increase of the right atrium size shifts the right heart border laterally;

the left ventricle shifts the left heart border. The right ventricle lifts the heart, moving the

apex superolaterally. The left atrium is behind the heart and on enlarging may project a

second border over the right side of the heart. The left atrial appendage may enlarge and

may produce a bump at the upper left heart border. Often the heart just appears generally

enlarged and correlates with heart failure; occasionally this may be due to a pericardial

effusion and is termed the ‘water bottle sign’.

The differential diagnosis for cardiomegaly includes ischaemic heart disease, valve dis-

ease, pericardial effusion/cardiac tamponade, dilated cardiomyopathy and pulmonary

embolism. In this patient, the presentation is suspicious for a pericardial effusion, prob-

ably malignant in origin and is confirmed on computed tomography (CT) (Figure 28.2).

(a)

(b)

(c)

Figure 28.2 (a) The presenting radiograph, (b) the coronal CT shows a rim of lower attenuation

fluid around the heart, (c) radiograph after paracentesis.

The pericardium covers the heart and great vessels, with the exception of only partially

covering the left atrium and normally contains less than 50 mL of transudate fluid. To

be distinctive on chest X-ray more than 250 mL needs to be present. The type of excess

fluid depends on the cause:

• transudate - congestive heart failure, hypoalbuminaemia;

• exudate - infection, autoimmune disease (e.g. rheumatoid arthritis, systemic lupus

erythematosus, hypersensitivity);

• blood - trauma, surgery, rupture, myocardial infarction, neoplasm;

• lymph - neoplasm, surgery.

An echocardiogram is the next investigation of choice and may be used to guide inser-

tion of a pericardial drain.

CASE 29: SKATEBOARDER WITH A PAINFUL FOOT

History

A 13-year-old boy was skateboarding when he fell forwards onto steps and twisted his

right foot. His description of the injury sounds as if it involved inversion of the foot. He

is taking no medication and there is no significant medical history.

Examination

The boy is a fit 13 year old who appears well but in discomfort. The right mid foot is

swollen and tender, more over the lateral aspect. The ankle joint is not painful but there

is pain in the foot on moving the ankle joint. There are no other injuries.

You arrange plain radiographs of the right foot (Figure 29.1).

Figure 29.1 Anterior-posterior radiograph of

the right foot.

Figure 29.2 Magnified oblique

radiograph of the right foot.

Questions

• Given the history, where would you look for an injury?

• What do the radiographs show?

• What might be confusing about the appearance of this injury?

• What other foot fractures should you consider?

ANSWER 29

Given the history of inversion, a common injury, the lateral side of the foot, particularly

the base of the fifth metatarsal should be checked. Forced dorsiflexion suggests the shafts

of the metatarsal and phalanges could also be injured.

The radiographs show a complex lucency through the base of the right fifth metatarsal,

in keeping with a fracture (Figure 29.2). There is associated soft tissue swelling. No other

fractures are seen.

The appearance of the fracture is complex. Reviewing the whole foot, multiple epiphy-

ses are noted consistent with a 13 year old with active growth plates which may cause

some confusion in interpretation of the radiographs. An unfused apophysis (secondary

ossification centre) lies parallel to the lateral edge of the base of the fifth metatarsal. The

transverse fracture line crosses the apophysis and base of the metatarsal. Fractures at the

base of the fifth metatarsal are common and reflect an avulsion injury of the peroneus

brevis tendon, typically on inverting the foot. The fracture edge is typically at right

angles to the metatarsal lateral cortex and should not be confused with the apophysis, if

present. There may also be an ossicle close the fifth metatarsal base. Ossicles should have

a smooth outline with a regular or corticated edge.

Other common foot injuries to be considered that can be subtle in appearance are:

• Lisfranc fractures (see Case 87), in which the Lisfranc ligament at the base of the first

to fourth metatarsals is injured; there may be avulsion fragments between the first and

second metatarsal bases and the alignment of the metatarsal shafts and cuneiforms is

lost;

• avulsions, appearing as small flakes of bone around the interphalangeal joints where

the flexor, extensor tendons insert;

• stress fractures of the shafts of predominantly second and third metatarsals in long

distance runners or people with a walking injury; these may be difficult to see and

appear initially only as a periosteal reaction;

• fracture through the first metatarsal ossicles.

KEY POINTS

• The mechanism of injury and site of symptoms may help to find subtle injuries.

• It is important to look around the edge of every bone, as small avulsions and stress

fracture periosteal reactions are easy to miss.

• Review the whole foot and beware of ‘satisfaction of search’ - where you stop looking

after finding an injury. Multiple injuries are common in trauma.

CASE 30: LEFT-SIDED LOIN PAIN

History

A 24-year-old man presents with sudden onset left upper quadrant pain radiating to the

groin with mild haematuria. He has no history of previous episodes or past renal prob-

lems. There is no history of lower urinary tract symptoms. He is otherwise fit and well

with no medical problems or relevant family history. He smokes 10 cigarettes per day and

drinks around 10 units of alcohol per week.

Examination

He is well with a pulse of 94 per minute but otherwise normal observations. The chest

examination is normal with normal heart sounds. The abdomen is soft but tender on the

left side, most notably over the left renal angle and left inguinal fossa. Urinalysis shows

blood 4+ but no protein or nitrites.

You arrange an urgent intravenous urogram (IVU) (Figure 30.1).

(a)

(b)

Figure 30.1 (a) Control and (b) 20-minute images from an intravenous urogram. Pelvic views

were normal.

Questions

• What is a urogram?

• What are you looking for on the control image and do you see any abnormality?

• What does the 20-minute image show?

• What is the differential diagnosis?

ANSWER 30

An IVU consists of a control image without contrast to look for calcification. Contrast is

then given intravenously and images are taken while the contrast passes through the kid-

neys (nephrogram phase) and then as it drains through the collecting system and ureters

into the bladder. The IVU is becoming a rather old-fashioned test because it provides only

limited anatomical information and is being replaced by pre, post and delayed contrast

phase computed tomography (CT).

The control image (Figure 30.2a) is reviewed for calculi (none seen) and the renal outline,

which in this case appears enlarged and lobulated bilaterally (Figure 30.2b).

(b)

Figure 30.2 (a) Control and (b) corresponding coronal CT slice demonstrating the renal outline

and appearance.

The 20-minute IVU radiograph shows drainage of contrast through the collecting system

on the right that has a slightly distorted appearance. No drainage is seen on the left,

suggesting obstruction, confirmed on later images with a delayed nephrogram and slow

accumulation of contrast in a dilated collecting system and due to a small stone, not seen

on the plain images, at about the level of the pelviureteric junction (outflow of the left

kidney) seen on CT.

There is an underlying bilateral kidney disorder with lobulated increase in size due to

cyst formation. The differential for cystic diseases of the kidney includes acquired simple

cysts (most common with increasing age and few in number), developmental disorders

(e.g. multicystic dysplastic kidney), genetic causes (e.g. autosomal recessive (ARPKD) and

dominant (ADPKD) polycystic kidney disease), systemic diseases (e.g. Von Hippel–Lindau

syndrome and tuberous sclerosis) or malignancy in the form of cystic renal cell carci-

noma. This patient has newly diagnosed ADPKD.

Unlike ARPKD that presents in childhood with renal failure and may be diagnosed pre-

natally, ADPKD is often clinically silent until it presents in adulthood, either with com-

plications such as stones, haematuria, hypertension or renal failure (typically mean age

ANSWER 31

There is a horizontal fat-fluid line, a lipohaemarthrosis, in the suprapatella pouch seen on

the cross-table horizontal lateral view. There is also a fracture of the lateral tibial plateau,

seen on the AP projection, with minimal displacement and loss of height.

A lipohaemarthrosis results from an intra-articular fracture with escape of fat and

blood from the bone marrow into the joint. Ideally the patient has been lying supine for

5 minutes to allow the fat and blood to separate. The fat rises and is less radio-opaque.

If seen, a lipohaemarthrosis indicates a tibial plateau or distal femoral fracture even if

the fracture is not apparent. Conversely, in a significant proportion of tibial fractures a

lipohaemarthrosis is not seen, although a haemarthrosis or effusion that appears as soft

tissue without a fluid level in the suprapatella bursa is likely to be present.

A computed tomography (CT) scan is done to image the extent of injury and plan surgery

(Figure 31.2).

Fat on

fluid level

(b)

Figure 31.2 (a) Axial and (b) sagittal CT slices of the right knee demonstrating the suprapatellar

lipohaemarthrosis.

There are a number of classification systems, such as the Schatzker classification, that

recognize patterns of fragmentation and displacement for tibial fractures. It is important

to recognize that a significant proportion of fractures will have associated meniscal, col-

lateral and cruciate ligamentous injury. These are better assessed by magnetic resonance

(MR) which can also identify occult fractures.

Tibial plateau fractures may be either low or high energy. The majority of tibial plateau

fractures are in patients over 50 years. Osteoporosis in older women is a contributing

factor in low energy fractures and typically results in a depressed fracture. Tibial plateau

fractures in younger patients are commonly the result of high energy injuries. The most

common mechanism is a valgus force at the knee while weight bearing or with axial

loading, typically either road traffic accidents or sports-related injuries.

KEY POINTS

• A fat-fluid level in the suprapatella bursa indicates a lipohaemarthrosis and is likely to

indicate a tibial plateau fracture even if not seen on plain radiographs.

• Increased size of the suprapatella bursa most likely indicates an effusion or a haemarthrosis.

CASE 32: STRANGE BONE APPEARANCE AFTER FALLING

History

A 77-year-old woman presents to the accident and emergency department after slipping

on ice and falling, hurting her left hip. She is unable to weight bear on her left leg. There

is no history of significant past joint pain or swelling. Before falling she had mildly

limited mobility but was otherwise active and well. Other than bendroflumethiazide for

hypertension there is no significant medical history.

Examination

The left leg is shortened with deformity around the hip. There is bruising over the lateral

aspect but no neurological or vascular abnormality is noted in the leg. Her observations

and the rest of the examination are normal.

You organize a pelvic and left hip radiograph and review a previous image of the left

hip (Figure 32.1).

Figure 32.1 Current AP pelvic radiographs

(left) and AP hip radiograph (right) from

1 year earlier.

Questions

• What abnormality is seen on the pelvic

radiograph.

• What is the differential diagnosis for

this appearance?

• What would you do next?

ANSWER 32

The pelvic radiograph shows a fracture through the proximal femoral shaft with displace-

ment of the distal femur and angulation of the proximal fragment. The radiographs also

show a longstanding abnormal bony appearance of most of the left femur with expansion

(compared with the right), cortical thickening and trabecular coarsening, most prominent

around the femoral head and neck. There is also bowing of the femoral shaft.

The differential diagnosis includes Paget’s disease, osteomyelitis, metastatic carcinoma

and myelofibrosis. Trabecular coarsening and cortical thickening is quite characteristic

of Paget’s disease. There is no history or other findings to suggest metastatic cancer

(typically multiple sclerotic lesions in breast or prostatic cancer) or osteomyelitis, and the

asymmetry makes myelofibrosis less likely.

Paget’s disease is a disorder of bone remodelling which may occur in single or multiple

bones and typically affects spine, pelvis, femur and skull. The aetiology is not known,

however, the disease progresses through a resorption, lytic phase with excessive osteo-

clastic activity to a bone formation osteoblastic sclerotic phase with a mixed phase in

between. Paget’s disease occurs predominantly in older patients, affecting less than 3 per

cent of patients around 50, rising to as much as 10 per cent in the over 80s. There is a

slightly higher incidence in Europeans and males.

Figure 32.2 demonstrates Paget’s disease in other bones. In the spine, the vertebral bodies

typically become enlarged with a prominent cortical margin (picture frame vertebrae) or

become sclerotic, mimicking lymphoma or metastatic disease. In the pelvis, typical find-

ings include thickening of the iliopectineal line (see arrows, Figure 32.2a) in early stages,

progressing to patchy sclerosis and lucency in later stages.

(a)

(b)

Figure 32.2 Paget’s disease in (a) the right side of the pelvis and (b) an L3 vertebral body of

different patients.

100

ANSWER 33

The lateral image demonstrates anterior slip of L5 on S1 by about 25 per cent of the vertebral

width, otherwise termed spondylolisthesis or anterolisthesis. The degree of slip is graded in

steps of 25 per cent (i.e. <25 per cent grade 1, 25-50 per cent grade 2, etc.). A lucency is seen

through the pars interarticularis - the portion of the neural arch that connects the superior

and inferior articular facets, suggesting a bony defect. This is otherwise known as spondylo-

lysis. On oblique radiographs, the posterior elements form the appearance of a Scottie dog

and a break in the pars interarticularis has the appearance of a collar around the neck.

A computed tomography (CT) scan has been obtained to examine the bony structures

(Figure 33.2). Magnetic resonance (MR) would be useful if the nerve roots or spinal cord

need to be imaged, although the bony structures are less well seen.

(a)

(b)

(c)

Figure 33.2 (a) Axial, (b) sagittal and (c) oblique CT slices through the L5 vertebra showing

bilateral pars defects (see arrows), widening of the spinal canal and a ‘Scottie dog’ projection

with the pars defect representing the dog’s collar.

Spondylolysis is thought to be caused by stress fracturing of the pars from repeated

minor trauma and may occur early in life. Hereditary pars hypoplasia is also believed to

be a factor. Patients with spina bifida occulta have an increased risk for spondylolysis.

Spondylolysis can also occur secondary to neoplasm, osteomalacia, osteomyelitis and

bone disorders such as Paget’s disease and osteogenesis imperfecta.

The L5 vertebra is most frequently affected, a smaller proportion at L4 or L3, and it is

unusual for spondylolysis to occur at several levels. Seventy-five per cent are bilateral.

Lyses occur much less commonly at other lumbar or the thoracic levels.

Patients with bilateral pars defects can develop spondylolisthesis. The vertebral body slips

forward while the posterior elements remain fixed so that the spinal canal widens. Stability

is provided by the soft tissues and ligaments. Degenerative change is a more common cause

in older patients. Increased motion of the facet joints allows movement but slip of the intact

vertebra results in spinal canal stenosis and symptoms. Treatment depends on the type of slip,

age of patient and symptoms and ranges from conservative management to surgical fixation.

KEY POINTS

• Spondylolysis is a defect through the pars interarticularis, usually at L5 or L4, probably

the result of stress fracturing.

• Spondylolisthesis is slip, usually anteriorly, of one vertebral body on another and may

be the result of spondylolysis in younger patients or, more commonly, degenerative

change in older patients.

104

CASE 34: VOMITING BABY BOY

History

A 6-week-old boy is referred urgently to the paediatric department by his general prac-

titioner (GP) with a 1-week history of vomiting after feeds and weight loss. His mother

describes forceful vomiting occurring during or shortly after feeds; the vomit does not

appear bile stained. He appears to have normal appetite and no other symptoms. No other

members of the family seem affected.

Examination

The baby is apyrexial, mildly dehydrated with normal observations. The chest is clear and

abdomen soft and not distended. There is a small palpable mass in the right upper quad-

rant and after feeding some peristalsis under the skin in the epigastic region is observable.

You organize an ultrasound scan of the upper abdomen (Figure 34.1).

(a)

(b)

Figure 34.1 (a) Transverse and (b) longitudinal ultrasound images through the liver and adjacent

structures.

Questions

• Which organs lie immediately behind the liver?

• What is the differential and most likely diagnosis?

• Are there any risk factors?

• What is the treatment?

105

ANSWER 34

Figure 34.1a shows a transverse ultrasound view of the right upper quadrant with a

prominent tubular pylorus just behind the liver in keeping with pyloric stenosis. By

viewing the pylorus over a period of time (if baby allows), altered pyloric function can

be viewed with limited or absent flow of stomach contents through to the duodenum

and ineffective gastric peristalsis, which may sometimes be observable by eye. Pyloric

muscle thicker than 4 mm, length >17 mm and transverse diameter >14 mm are criteria

sometimes used, although this will depend on the age of the baby. Figure 34.2 shows

transverse ultrasound with measurements.

Pyloric stenosis is the most common cause of intestinal obstruction in infancy (2-4 per

1000). It is due to hypertrophy and hyperplasia of the muscular layers with thickening and

lengthening of the pylorus, causing func-

tional gastric outlet obstruction. Typical

features are presentation at

2-8 weeks

(although can present up to 5 months). The

pylorus may be palpable, about the size of

a large olive. Forceful, projectile vomit-

ing that is not bile stained is suggestive of

pyloric obstruction. Blood tests typically

indicate hypochloraemic alkalosis, due to

vomiting gastric acid, and dehydration.

The differential diagnosis includes:

• infections including gastroenteritis and

urinary tract;

• gastritis, gastroesophageal reflux, hia-

tus hernia;

• malrotation, pyloric atresia, web or dia-

phragm;

• congenital adrenal hyperplasia (due to

metabolic imbalance);

Figure 34.2 Transverse ultrasound with

• poor feeding practices.

measurements. The gastric mucosa is bright,

the muscle dark.

If the diagnosis is not clear on ultrasound, a contrast meal and follow through that

examines the stomach and small bowel is the next step. Pyloric stenosis typically shows

shouldering of the gastric antrum outlet with a long, narrow pyloric canal (string sign)

on a contrast meal. Malrotation and other causes of outflow obstruction also show char-

acteristic appearances.

There is a higher incidence of pyloric stenosis in first-born boys (M: F 4:1). There is also

evidence for heritability and that the condition appears to be developmental rather than

congenital. The definitive treatment is surgical pyloromyotomy, where the pylorus mus-

cle is cut longitudinally to release the pyloric tension.

KEY POINTS

• Pyloric stenosis typically presents within 2-12 weeks as non-bilious vomiting.

• Ultrasound appearances can be diagnostic with the pylorus appearing lengthened and

thickened and no significant flow of stomach contents through to the duodenum.

106

ANSWER 35

The chest radiograph shows several circular soft tissue lesions in both hemithoraces, most

prominent on the left.

The first issue is how to describe the lesions. Convention is that a ‘nodule’ is smaller and

a ‘mass’ larger than 3 cm. Nodules can be thought of as miliary (multiple, with size and

appearance of seeds), small (2-5 mm) or large (>5 mm). They may be single or multiple,

discrete or confluent, uniform or variable in size, contain calcification or cavities and be

associated with lymphadenopathy, pleural effusions or pleural or rib lesions. Noting these

features can help to narrow down the list of differentials.

In this case the list of differentials for multiple variable size soft tissue pulmonary nod-

ules includes metastases, Wegener’s granulomatosis, rheumatoid nodules, sarcoidosis,

amyloidosis (often calcified), arteriovenous malformations and abscesses. Most likely are

metastases from a possible renal primary. Metastases often have a rounded mass appear-

ance, having grown rapidly from a bloodborne deposit, whereas primary lung tumours

often have an irregular, infiltrative or spiculated appearance.

The lungs are one of the most common sites for haematogenous spread of tumours,

particularly from kidney, osteosarcoma, thyroid, melanoma and breast. When that list

is adjusted for tumour incidence, lung metastases are most commonly seen for breast,

kidney, head and neck, and colorectal tumours.

A computed tomography (CT) scan to characterize the kidney lesion and to stage the

disease is required (Figure 35.2). In particular, evidence of any growth of the tumour

into surrounding structures or lymph nodes or into the renal vein or opposite kidney will

alter the treatment. Renal tumours account for 3 per cent of adult tumours and the large

majority are renal cell carcinomas (RCCs). Thirty per cent of patients with RCC present

with metastases, which in addition to lung occur in soft tissue, bone and liver.

Figure 35.2 Axial contrast-enhanced CT

through the kidneys showing a large left renal

tumour.

KEY POINTS

• The size, number, distribution and properties of lung nodules can help decide the

differential diagnosis.

• Kidney, osteosarcoma, thyroid, melanoma and breast tumours most commonly

metastasize to the lungs.

• Renal cell carcinoma is the most common adult kidney cancer.

108

CASE 36: SUDDEN ONSET WEAKNESS IN AN 80-YEAR-OLD WOMAN

History

An 80-year-old woman was brought into the accident and emergency department from

her sheltered accommodation with sudden onset right-sided weakness and slurred speech.

She is not known to have had a previous stroke or neurological symptoms. She has a past

history of chronic obstructuve pulmonary disease (COPD) and 50 pack-years smoking.

Examination

There is right-sided leg and arm weakness (3/5), mild slurring of speech and left facial

droop. The chest is clear and abdomen soft and non-tender. Observations show a regular

heart rate of 72/minute, blood pressure of 132/82 and no pyrexia. A computed tomogra-

phy (CT) scan of the head is arranged (Figure 36.1).

(a)

(b)

Figure 36.1 Axial CT slices through brain at two levels: (a) images without contrast; (b) images

with contrast.

Questions

• What is the differential diagnosis for ‘stroke’?

• What does the CT demonstrate?

• Is contrast used regularly for head CTs?

• What is your most likely diagnosis and what other investigations would you arrange?

109

ANSWER 36

The aim of imaging is early diagnosis and to differentiate ischaemic and haemorrhagic

stroke. Stroke mimics include space-occupying lesions such as tumours, haematomas,

arterial dissections, abscess and acute infection

(often a urinary tract infection) in

patients with chronic cerebral degeneration such as dementia.

The computed tomography (CT) shows low attenuation regions within the subcortical white

matter of the superior right frontal lobe and posterior left frontal lobe in the region of the

motor cortex. A small central high attenuation area is in keeping with haemorrhage with

surrounding white matter oedema. Post contrast, both regions show avid ring enhancement.

Head CTs are almost always initially non-contrast. This is primarily to avoid obscuring

acute haemorrhage or haematoma that has mildly increased attenuation compared with

the surrounding brain. It also allows calcification to be identified. There are a number

of locations where calcification accumulates physiologically, including the choroid plexi

(posterior horns of the lateral ventricles), pineal gland and habenula (posterior end of the

third ventricle), falx, basal ganglia and vascular atheroma. Physiological calcification is

often symmetrically arranged or on the midline. Other calcifications may arise in lesions

associated with tumours (e.g. meningiomas), infection, arteriovenous malformations or

aneurysms, old haemorrhage and past surgery.

Contrast is given to improve the visibility of the vasculature (e.g. aneurysm, arterovenous

malformation) or lesions that often have abnormal vessels with defective blood-brain

barrier so that contrast is retained in the tissue.

The ring-enhancing lesions in this patient’s

case are most likely to be metastatic

tumour deposits from a remote primary. A

primary brain tumour is less likely in this

age group and the clinical picture is not

typical for brain abscesses, although the

appearance would be quite similar. A chest

radiograph would be the next investigation

(Figure 36.2), given the history of smok-

ing, although a staging CT of the chest,

abdomen and pelvis would be required for

treatment planning.

Only a few tumours account for about

95 per cent of brain metastases, most

commonly bronchial carcinoma, breast,

gastrointestinal tract, renal cell carcinoma

and melanoma.

Figure 36.2 Chest radiograph showing a right

mid zone mass and hilar lymphadenopathy.

KEY POINTS

• Although infarction is the most common cause of stroke symptoms, if the patient is

young or the history is inconsistent, consider stroke mimics such as tumours or arterial

dissections.

• Bronchial cancer is the most common metastasis to the brain.

110

CASE 37: YOUNG MAN WITH ANKLE PAIN

History

A 20-year-old man presents to the accident and emergency department with a painful

right ankle after twisting during football practice. He is barely able to put his weight on

the foot. The description sounds like an eversion injury. There is no other or previous

injury and the patient is otherwise fit and well. There is no significant medical history.

Examination

On examination the patient appears fit and well but in pain. There is swelling and ten-

derness over the right lateral malleolus. There is reduced range of movement at the ankle

joint. Observations are normal and there are no other significant findings.

You arrange radiographs of the ankle (Figure 37.1).

(a)

(b)

Figure 37.1 (a) Anterior-posterior (AP) view of the foot in 20 degrees external rotation to see

the ankle mortice with minimum overlap; (b) lateral view of the ankle.

Questions

• What do the radiographs show?

• How would you describe the abnormality?

• What are the features that help with a differential diagnosis?

• What are your most likely differentials?

111

ANSWER 37

The radiographs show a well-defined sclerotic lesion that is eccentrically positioned in

the distal femoral diaphysis. It appears to arise from the cortex and there is no associated

bony expansion, soft tissue swelling or periosteal reaction. The ankle joint is normally

positioned and regular in appearance. No fracture is seen. There is soft tissue swelling

over the lateral malleolus.

When reviewing the ankle it is important to check the joint space between the talus and

tibia/fibula which should be the same throughout. Small irregularities within the joint

space might indicate an osteochondral defect. Check for avulsion below the fibula and

posterior to the fifth metatarsal. Take care not to confuse fractures with ossicles com-

monly in this position and also posterior to the tibia.

There is quite a structured way of describing bony abnormalities that helps with deriving

a differential diagnosis. Consider:

• age;

• number of lesions (may require more imaging);

• location;

• position within the bone (i.e. diaphysis, metaphysis, epiphysis, subarticular, cortex or

medulla);

• density (sclerotic, lytic or mixed);

• borders - zone of transition well defined (narrow) or poorly defined;

• bony change - expansion, coarsened trabeculae, moth eaten (irregular holes also

termed permeative lucency), osteopenia;

• periosteal reaction - lamellar, spiculated (tends to be associated with aggressive proc-

esses and can be hair on end, e.g. Ewing sarcoma, or sunray, e.g. metastases).

This patient’s lesion is a solitary sclerotic cortical lesion with benign appearance and, in

this age group, a healing fibrous cortical defect is most likely. The differential includes

osteoid osteoma (particularly with a central lucency or nidus). Less likely is a bone

infarct (check for history of sickle cell disease, steroids), bone island or fibrous dysplasia.

Unlikely is metastasis (age, appearance), primary bone sarcoma or osteomyelitis (typically

aggressive periosteal reaction).

A fibrous cortical defect (or non-ossifying fibroma if greater than 2 cm) is the most fre-

quent benign bony lesion in children and adolescents. These lesions are developmental

abnormalities and usually an incidental finding on radiographs. The lesion develops in

the distal metaphysis of a long bone as a radiolucent and eccentrically located lesion,

with thin cortex and sclerotic or scalloped margins while the growth plate is open. There

is typically spontaneous healing with sclerosis once the growth plate has ossified. Surgery

is considered if there is risk of a fracture (occupying greater than 50 per cent of the trans-

verse diameter), symptoms or enlargement.

KEY POINTS

• A good description of the lesion helps with deriving a differential diagnosis.

• Age is one of the main discriminators in deciding differentials.

112

CASE 38: PAINFUL SHOULDER

History

A 45-year-old man slipped and fell backwards onto his outstretched right arm. He

presents complaining of severe shoulder pain and loss of movement. The shoulder is also

swollen.

Examination

The patient holds his arm in slight abduction and external rotation. The shoulder is

‘squared off’ (i.e. box-like) with loss of deltoid contour compared with opposite side. The

humeral head is just palpable anteriorly below the clavicle in the subcoracoid area. A

careful assessment is made to check his radial pulses for a vascular injury and the axillary

nerve function for regimental badge sensory loss over the deltoid and deltoid contraction

on attempted abduction. Plain images are taken of the shoulder (Figure 38.1).

Figure 38.1 Posterior-anterior (PA) view of the right shoulder.

Questions

• What differential diagnoses should you consider?

• What complications can arise?

• What further imaging would be helpful?

113

ANSWER 38

The history and examination all suggest an anterior shoulder dislocation. Often in the

case of trauma, shoulder injuries have to be assessed initially on the basis of a PA projec-

tion, which in this case confirms displacement of the humeral head inferiorly relative to

the glenoid. Axial and Y views are nearly perpendicular to the PA projection and show

the position of the humeral head. Figure 38.2 shows the humeral head anterior to the

glenoid.

(a)

(b)

Figure 38.2 (a) Y view facing the glenoid fossa with the scapula describing a Y; (b) axial view

of the right shoulder.

The imaging helps to distinguish the differential diagnosis of glenohumeral dislocation,

of which anterior dislocation (96 per cent) is much more frequent than posterior (3 per

cent) and inferior (1 per cent). Pseudo dislocation, where the humeral head is subluxed

but not consistently dislocated, is associated with chronic shoulder joint instability, bra-

chial plexus injury or haemarthrosis. Acromioclavicular dislocation and sternoclavicular

dislocation should also be considered although much less common.

Posterior dislocations characteristically occur in trauma or seizure and can be harder to

recognize, particularly if an axial or Y view has not been obtained. Suspicious features

include fixed internal rotation (lightbulb sign), widening of the glenohumeral joint space

(rim sign) with loss of overlap of the humerus over the glenoid.

Anterior dislocation can be associated with fracture of the greater tuberosity, anterior tear

of the glenoid labrum (Bankart lesion), fracture of the anterior rim of the glenoid and an

impaction fracture of the posterolateral surface of the humeral head (Hill-Sachs lesion)

where it impacts on the glenoid rim. If not identified, recurrent dislocations are likely.

The rotator cuff muscles may also be injured by traction.

Treatment requires adequate analgesia and sedation before relocating the joint. Imaging

and neurovascular examination is performed before and after reduction.

114

CASE 39: CHEST PAIN AFTER FALLING

History

A 75-year-old man is brought to his general practice by his daughter. He complains of

left-sided chest pain on inspiration. On further questioning it becomes apparent that he

has had a recent fall. He lives alone and independently with frequent visits from his

daughter who is concerned that there have been several falls. The patient is on blood

pressure medication and takes a statin for previously high cholesterol. Reviewing his

notes you see a previous attendance 2 years earlier for a fall and several episodes of

treatment for pneumonia. There is a past history of smoking but no other significant

medical history.

Examination

The observations are normal. He is thin. There is some bruising over the left side of the

thorax and a notable low thoracic kyphosis. There are bilateral fine inspiratory crackles.

The heart sounds are normal. The abdomen is unremarkable and no neurological or sig-

nificant cognitive abnormality is noted.

A chest radiograph (Figure 39.1), electrocardiogram (ECG) and blood tests are arranged.

Figure 39.1 Chest radiograph.

Questions

• What does the radiograph show?

• What is the differential diagnosis?

• What further imaging would you consider?

• What other investigations should you consider?

117

ANSWER 39

Although the history and examination make rib fractures very likely, radiology is rarely

indicated simply to look for low energy traumatic rib fractures. In this patient’s case there

are questions as to the cause of the fall. A chest radiograph is indicated for a possible

chest infection or lesion and a thoracolumbar spine radiograph for the possible cause of

the kyphosis.

The chest radiograph shows recent fractures of the left sixth to ninth ribs posterolaterally.

There are also old fractures of the right ribs posterolaterally. Features that are common

in trauma are fractures in a line and a posterolateral position, although this will depend

on the type of trauma. Old fractures have healed and the bone cortex is continuous but

the rib may be distorted. Recent and new fractures have discontinuous cortex but recent

fractures show signs of healing with callus and bone remodelling that is absent in new

fractures.

Do not stop looking once you have seen the fractures! Also look for other fractures (e.g.

spine), bone lesions and examine the lungs, pleura and heart. On this radiograph there

is consolidation in the right lower zone and a probable hiatus hernia gas bubble behind

the heart.

The spine radiograph reported wedge compression fractures of the T11 and T12 vertebral

bodies together with some small sclerotic and lytic lesions in the lumbar vertebrae. The

initial blood tests show iron deficiency anaemia and raised erythrocyte sedimentation rate

(ESR). This suggests an underlying systemic disease that affects bone and includes bowel

or chest malignancy with bone metastases, myeloma or prostate carcinoma. The patient

should be referred to the older person team for further investigation. From an imaging

point of view this probably includes a computed tomography (CT) scan of the chest,

abdomen and pelvis, although a bone scan could be helpful if sclerotic bone metastases

from prostate or bowel carcinoma are suspected.

If blood tests suggest myeloma, a skeletal survey for lytic lesions could be done. Bone

scans have lower sensitivity for lytic bone lesions which appear as photopenic regions

of reduced uptake. The tracer used in bone scans, ⁹⁹Tc-MDP (technetium-99 conjugated

with methylene diphosphonate), is taken up primarily by osteoblastic activity typical in

sclerotic bone lesions.

The National Service Framework for older person care recommends a formal falls assess-

ment in patients at risk and regular medication review.

KEY POINTS

• Radiology is rarely indicated simply to look for rib fractures.

• In older patients the ‘Occam’s razor’ approach of assuming only one underlying

pathology has to be modified to allow for several interacting pathologies.

• Avoid ‘satisfaction of search’ and keep looking after spotting the first abnormality.

118

CASE 40: SWELLING OF THE BIG TOE

History

A 57-year-old man presents to his general practitioner (GP) with pain and swelling of his

left big toe. He reported that this had been a longstanding problem over the last 7 years

but had just put it down to ‘old age’ and did not want to trouble his GP with it. The pain

and swelling would come and go in waves. He noted, however, that these episodes were

now more frequent and he would struggle to weight bear on that side at times. On this

occasion the pain had suddenly started at night and had been getting worse in flares ever

since. In his past medical history he had a hernia operation 14 years ago. He was on treat-

ment for hypertension and hyperlipidaemia with bendroflumethiazide and simvastatin,

respectively. He is an ex-smoker and drinks 14 units of alcohol per week. He is not aware

of any history of trauma.

Examination

Examination revealed a tender, erythematous right big toe with a markedly reduced

range of motion at the first metatarsophalangeal joint. He had a moderately raised white

cell count of 12 and his erythrocyte sedimentation rate (ESR) was also raised. Serum

urate levels were elevated. He was afebrile and observations were otherwise normal.

Radiographs of the foot were taken (Figure 40.1).

(a)

(b)

Figure 40.1 (a) Anterior-posterior and (b) oblique radiographs of the foot.

Questions

• What do the radiographs of the foot demonstrate?

119

ANSWER 40

Figure

40.1 demonstrates

‘punched-out’ lytic bone lesions with overhanging edges

involving the first metatarsophalangeal joint with marginal sclerosis. There is the appear-

ance of ‘rat bites’ with an overlying calcified soft-tissue swelling. These classical findings

are consistent with longstanding gout.

Gout is defined as a peripheral arthritis that results from the deposition of sodium urate

crystals in one or more joints. It has many contributing factors, but two central processes

are involved in its development: the overproduction of uric acid and the underexcretion

of uric acid. A multitude of conditions, including renal disease, have been implicated,

but the vast majority of cases are idiopathic. Podagra (another name for pain in the first

metatarsophalangeal joint) is the classic presentation of gout. In general, the symptoms

of gout appear suddenly at night and occur in men with hyperuricaemia who are aged

30-60 years.

Gout is also associated with hyperlipidaemia, hypertension, kidney failure, obesity and

insulin resistance. Other ‘social’ factors such as alcohol intake also increase the risk of

gout. An increase in uric acid levels and resulting precipitation of gout is a side effect

of thiazide diuretics.

Patients with new onset of acute gout usually have no radiographic findings and the

classic features seen in this case are usually not seen until 6-12 years after initial attack.

Early radiologic findings in gout are limited to the soft tissues and involve asymmetric

swelling in the affected joints. There is preservation of joint space initially. In the inter-

mediate stage of disease, gout causes subtle changes in the bony structures on plain film

radiographs. In the periphery of affected joints, small ‘punched-out’ lytic bone lesions

arise, often with sclerosis of margin. Obtaining two views is important to appreciate

these subtle findings. Definitive diagnosis is made by finding the negatively birefringent

crystals on polarized microscopy of synovial fluid aspirate.

The hallmark sign of late-phase gout is the appearance of large and numerous inter-

osseous tophi on plain film radiographs. Calcific deposits in gouty tophi are seen in

approximately 50 per cent of cases (only calcium urate crystals are opaque) and ‘mouse/

rat bite’ erosions develop due to longstanding soft tissue tophi. Joint space narrowing

and cartilage destruction is seen late in the course of the disease.

KEY POINTS

• Classical plain radiographic features of longstanding gout include ‘punched-out’ lytic

bone lesions with overhanging edges, marginal sclerosis and the appearance of ‘rat

bites’ with an overlying calcified soft tissue swelling (tophus).

• These features usually are not usually seen until several years after initial attack and are

present in around 50 per cent of patients.

120

CASE 41: A YOUNG MAN WITH PROGRESSIVE DYSPNOEA ON

EXERTION

History

A 38-year-old man presents to his general practitioner (GP) with progressive dyspnoea

on exertion developing steadily over the past 2 months. He says that he is now unable to

walk 100 m before becoming severely short of breath and having to stop. He also noted

the development of a non-productive cough over a similar time scale and more recently

developing a fever. He had never experienced anything like this before and was previ-

ously fit and well with no past medical history of note. In his social history he reported

having unprotected sex with both men and women.

Examination

On examination his respiratory rate was 22 per minute, fever (with a temperature of

37.9°C), a few crackles and wheezes over both lung fields. On the basis of the examination

the GP sent the patient to the accident and emergency department.

In casualty, oxygen saturation was 90 per cent breathing air. Haematology results showed

a normal white cell count. Biochemistry and liver function tests were normal. A retro-

viral screen showed he was human immunodeficiency virus (HIV) positive with a CD4

count below 200 cells/μL, consistent with acquired immune deficiency syndrome (AIDS).

He was referred for a chest radiograph (Figure 41.1), on the basis of which a computed

tomography (CT) was requested and performed (Figure 41.2).

Figure 41.1 Chest radiograph.

Figure 41.2 CT scan.

Questions

• What is the likely cause of his increasing shortness of breath?

• What do the chest radiograph (Figure 41.1) and subsequent CT scan (Figure 41.2)

show?

121

ANSWER 41

The most likely diagnosis based on the clinical history and imaging findings is pneumo-

cystis pneumonia (PCP) or pneumocystosis, which is a form of pneumonia, caused by the

yeast-like fungus Pneumocystis jirovecii. The older name Pneumocystis carinii (which now

only applies to the Pneumocystis variant that occurs in animals) is still in common usage.

Plain chest radiograph (Figure 41.1) demonstrates perihilar interstitial reticular shadow-

ing with cyst formation. There is relative sparing of the apices and both bases. The axial

enhanced CT image at the level of the pulmonary trunk (Figure 41.2) demonstrates perihilar

ground-glass change and cystic changes, indicating the development of pneumatoceles.

Pneumocystis organisms are commonly found in the lungs of healthy individuals. It is

believed most children have been exposed to the organism by the age of 4 years, and

its occurrence is worldwide. The organism is a rare cause of infection in the general

population, however it is a frequent cause of morbidity and mortality in persons who are

immunocompromised, especially patients with AIDS.

Patients who do not have AIDS but are immunocompromised and at risk for PCP include

individuals with haematologic malignancies, organ transplant recipients and those

receiving long-term steroid or cytotoxic therapy, including patients with systemic vas-

culitis or other autoimmune deficiency. Other patients with immune deficiency disorders

who are at particular risk for PCP include those with thymic dysplasia, those with severe

combined immunodeficiency, and those with hypogammaglobulinaemia. Severe malnu-

trition may also predispose individuals to PCP.

The risk of pneumonia due to PCP increases when CD4 levels are less than 200 cells/μL.

The symptoms of PCP are non-specific. PCP in patients with HIV infection tends to run a

more subacute, indolent course and tends to present much later, often after several weeks

of symptoms, compared with PCP associated with other immunocompromising conditions.

Chest radiographs should be included in the initial evaluation for PCP. Frequently, these

are the only images required. Characteristically, the distribution is central in location

with bilateral diffuse symmetric finely granular, reticular interstitial/airspace infiltrates

with perihilar and basilar distribution. Chest radiograph is normal in 10-39 per cent of

patients with PCP. Hilar lymphadenopathy and pleural effusions are uncommon (seen in

less than 5 per cent).

CT (in particular, high-resolution CT) scanning is more sensitive than chest radiography for

the detection and exclusion of PCP pneumonia, and the results may be positive when chest

radiograph findings are normal. CT findings include patchwork pattern bilateral asymmetric

patchy mosaic appearance with sparing of segments/subsegments of pulmonary lobe or a

‘ground-glass’ pattern as in this case with bilateral diffuse airspace disease (fluid + inflamma-

tory cells in alveolar space) in symmetric distribution. Cysts are visible on chest radiographs

in 10 per cent of patients, although these are appreciated far more commonly on HRCT scans

(33 per cent). Findings of cysts or pneumatoceles are not infrequent in patients with PCP.

KEY POINTS

• PCP is the most common cause of interstitial pneumonia in immunocompromised

patients, which quickly leads to airspace disease.

• Chest radiograph findings may be normal in a significant number of patients with PCP.

• The classical chest radiograph features of PCP pneumonia, when present, are bilateral,

diffuse, often perihilar, fine, reticular interstitial opacification, which appears to be granular.

122

CASE 42: PAIN ON DEEP INSPIRATION

History

A 67-year-old man presents to the accident and emergency department as a referral

from his general practitioner (GP). Over the course of the preceding 12 hours he has been

experiencing pain in the left side of his chest, worst on deep inspiration. This is the first

ever such episode and he describes the pain as sharp and stabbing. He is an ex-smoker

with a 30 pack-year history. Emphysematous changes have been noted on a previous

chest radiograph and he takes a salbutamol inhaler as required along with an inhaled

corticosteroid regularly. Aside from a history of mild to moderate chronic obstructive

pulmonary disease he was otherwise well. He denies any history of trauma.

Examination

He is tachypnoeic with a respiratory rate of 33/minute and tachycardic with a heart rate

of 104/minute which electrocardiogram (ECG) confirms as sinus rhythm with no acute

changes. On examination of the respiratory system there is reduced expansion, a slightly

hyperresonant percussion note and reduced air entry on the left. Vocal resonance is also

reduced on the left. No added sounds are identified, however. Full blood count (FBC),

biochemistry and liver function tests are all normal. Blood gas analysis demonstrates

a PaO

2 of 9 kPa with a PaCO2 of 4.5 kPa. The patient is referred for a chest radiograph

(Figure 42.1).

Figure 42.1 Posterior-anterior (PA) chest radiograph.

Questions

• What abnormality do you see on the chest radiograph?

• What concerning features would you look for?

• How would you manage this patient?

123

ANSWER 42

The PA chest radiograph (Figure 42.1) shows a large left pneumothorax, which appears

tethered to the left costal pleura. There is a background of emphysematous change but no

evidence of mediastinal shift to suggest that the pneumothorax is under tension, which

would be an alarming feature requiring immediate intervention.

Pneumothorax refers to the presence of air within the pleural space. Diagnosis is estab-

lished on the plain chest radiograph by demonstrating an outer margin of the visceral

pleura known as the pleural line (delineating collapsed lung), separated from the parietal

pleura (chest wall) by a lucent space occupied by gas and devoid of any pulmonary

markings.

The pleural line demonstrating the margin of collapsed lung can sometimes be difficult

to detect in cases of a small pneumothorax. It is important to note that a skin fold may

mimic the pleural line. When a pneumothorax is suspected but not confirmed on inspira-

tory radiograph, an expiratory image may confirm the diagnosis. This is because at the

end of expiration, the constant volume of the gas within the pneumothorax is accentu-

ated by the reduction of the hemithorax.

Chest radiography is the first investigation performed to assess pneumothorax, because it

is straightforward, rapid, cheap and non-invasive. CT may be used in more complex cases,

for example in planning pleurodesis (usually in recurrent pneumothoraces) and it is more

sensitive than plain radiographs in detecting blebs or bullae or a small pneumothorax.

Pneumothorax is classified as spontaneous (atraumatic), traumatic, or iatrogenic:

• Spontaneous pneumothorax may be either primary (occurring in persons without

clinically or radiologically apparent lung disease) or secondary (in which lung disease

is present and apparent, as in this example). Most individuals with primary spontane-

ous pneumothorax have unrecognized lung disease; it is often thought to occur due

to rupture of a subpleural bleb.

• Traumatic pneumothorax is caused by penetrating or blunt trauma to the chest. Gas

enters the pleural space directly through the chest wall through visceral pleural pene-

tration or alveolar rupture resulting from sudden compression of the chest.

• Iatrogenic pneumothorax results from a complication of a diagnostic or therapeutic

intervention. With the increasing use of invasive diagnostic procedures, iatrogenic

pneumothorax has become more common.

In this large secondary pneumothorax with significant symptoms drainage is required to

remove the air from the pleural space. Needle aspiration is not usually adequate in such

cases and insertion of an intercostal drain is required. This has been done in Figure 42.2

with some resulting but as yet incomplete re-expansion of the collapsed left lung.

124

ANSWER 43

The lateral radiograph (Figure 43.1a) demonstrates elevated anterior and posterior elbow

fat pads, suggesting a joint effusion and is suspicious for an occult fracture. The magni-

fied AP image (Figure 43.1b) confirms a fracture of the radial head.

The preferred study for the evaluation of elbow trauma is conventional radiography and

the radiographic examination requires the acquisition of two views: the lateral view, ide-

ally in 90 degree flexion, and AP view in full extension.

The classic elbow ‘fat pad’ sign seen on lateral elbow radiograph is an invaluable soft tissue

finding in cases of intra-articular injury of the elbow. Fat is normally present within the

joint capsule of the elbow, but outside the synovium. As it is usually ‘hidden’ in the concav-

ity of the olecranon and coronoid fossae, fat is usually not visible on the lateral radiograph.

Injuries causing intra-articular haemorrhage/effusion, however, cause distension of the

synovium which forces the fat out of the fossa, producing triangular radiolucent shad-

ows anterior and posterior to the distal end of the humerus - the radiographic sail sign

(Figure 43.2).

The posterior fat pad (black arrow - Figure

43.2) is not normally seen on radiographs

and its presence is always an abnormal

finding that requires further investigation

for an occult fracture.

The anterior fat pad may be normally visu-

alized on lateral radiographs as a triangu-

lar radiolucency, although in the presence

of joint effusion it is displaced anteriorly,

becoming more pronounced and the anterior

margin becomes convex. Fat pad signs may

not be evident if the fracture is extracapsular.

Fracture of the radial head is the most

common type of elbow fracture in adults,

Figure 43.2

whereas fractures of the radial neck are

more common in children. Fractures of the

radial head and neck of the radius generally result from a hard fall on an outstretched

hand with the impact of fall driving the head of radius axially onto the capitulum of the

humerus.

Treatment depends on the degree of displacement, angulation and articular involvement.

Minor degrees such as that shown are often treated by early mobilization in a brace to

minimize later elbow stiffness.

KEY POINTS

• Radiographic examination requires two views: AP view in full extension and lateral

view, ideally in 90 degrees of flexion.

• The posterior fat pad is not normally seen on radiographs, and its presence is always

an abnormal finding that should prompt further investigation for occult fractures.

• Fat pad signs may not be evident if the fracture is extracapsular.

128

ANSWER 44

The AP and oblique images of the hand demonstrate a metacarpal neck fracture, with

volar angulation and displacement of the distal fragment. Note also prominent soft tissue

swelling of the hand.

A ‘boxer’s fracture’ is the common name for a fracture involving the neck of the fifth

metacarpal, which forms the knuckle of the little finger (but the same name may also

be used for a fracture at the neck of any of the metacarpals). It is usually caused by the

impact of a clenched fist with a skull or a hard, immovable object.

Only the collateral ligaments remain attached to the proximal phalanx and therefore

the metacarpal head is freed from any proximal stabilizing influence. The metacarpal

head tilts volarly, causing the joint to lie in hyperextension and the collateral ligaments

become slack. If the joint is allowed to remain in hyperextension, collateral ligaments will

shorten, leading to limited metacarpophalangeal flexion.

The little finger carpometacarpal articulation allows a flexion-extension arc of 20-30

degrees in addition to a rotatory motion, facilitating little finger opposition to thumb.

A true lateral radiograph is necessary with these fractures in order to measure the angle

of displacement of the distal fragment. The normal metacarpal neck angle is about

15 degrees and therefore a measured angle on film of 30 degrees is actually approxi-

mately 15 degrees.

These fractures are often angulated, and if severely so, require pins to be put in place

and realignment as well as the usual splinting. However, the prognosis on these fractures

is generally good.

KEY POINTS

• A boxer’s fracture is the common name for a break in the end of the little finger

metacarpal bone, also known as a fifth metacarpal fracture.

• The injury is commonly caused by punching something harder than the hand, for

example, a wall. The end of the metacarpal bone takes the brunt of the impact, which

usually breaks through the neck (which is the narrowest area near the end) and bends

down toward the palm.

130

ANSWER 45

Triquetral fractures typically occur from a hyperextension injury with the wrist in ulnar

deviation, however, can also occur with hyperflexion. Either the dorsal or volar radio-

triquetral ligaments may avulse triquetral fragments at their attachments. Behind frac-

tures of the scaphoid, triquetral fractures are the second most common carpal bone to

fracture. They are frequently seen as dorsal chip fractures only on the lateral projection

(Figure 45.2) since the pisiform usually overlies the triquetrum on the frontal projection

of the wrist (Figure 45.1). In this case there is a small avulsion from the dorsum of the

triquetrum seen only on the lateral projection (arrow, Figure 45.3).

Figure 45.3 Lateral view of the left wrist indicating the fracture.

Patients will usually complain of localized tenderness on the dorsum of the wrist.

The triquetrum may be identified by its pyramidal shape and by an oval isolated facet for

articulation with the pisiform bone. It is situated just distal to the ulna and the triangular

fibrocartilage complex, proximal to the base of the hamate.

The superior surface presents a medial, rough, non-articular portion, and a lateral convex

articular portion, which articulates with the triangular articular disc of the wrist. The infe-

rior surface, directed laterally, is concave, sinuously curved and smooth for articulation

with the hamate. The dorsal surface is rough for the attachment of ligaments. The tri-

quetrum articulates on its radial side with the lunate to which it is attached by the luno-

triquetral ligament. On the volar (palmar) aspect there is an articulation with the pisiform.

Triquetral fractures may divided into two types:

• Chip fractures: A chip fracture, usually off the dorsal radial surface, typically occurs

with a wrist hyperextension injury. Chip fractures can also occur with the hyperflexion.

• Mid-body fracture: Fractures through the mid-body of the triquetrum are less fre-

quent than a chip fracture. This type of fracture is usually due to a direct blow, or

may occur in conjunction with a perilunate dislocation. The dislocation may have

been reduced, so a triquetral fracture from the proximal radial aspect of the bone may

indicate the presence of a former dislocation.

KEY POINTS

• Triquetral fractures are the second most common fracture of the carpal bones.

• They are frequently seen as dorsal chip fractures only on the lateral projection as the

pisiform usually overlies the triquetrum on the AP projection of the wrist.

132

CASE 46: SHORTNESS OF BREATH AND PLEURITIC CHEST PAIN

History

A 55-year-old man is admitted to the accident and emergency department complaining

of gradual onset of shortness of breath over the course of several hours along with right-

sided chest pain aggravated by deep inspiration. He is complaining of mild lightheaded-

ness and feels the symptoms are getting worse. The pain is sharp and stabbing in nature.

He was previously fit and well. One day earlier he returned on a long haul flight from a

business trip to Asia. He denies any history of leg swelling.

Examination

Upon admission to hospital his oxygen saturation on air was 94 per cent and his res-

piratory rate was 20/minute. A chest radiograph failed to demonstrate any focal lesion.

Routine bloods were normal although D-dimer performed in the emergency department

was elevated. Electrocardiogram (ECG) demonstrated a mild sinus tachycardia heart rate

of only 102/minute. The accident and emergency team suspected a possible pulmonary

embolism (PE) and so a computed tomography pulmonary angiogram (CTPA) was per-

formed (Figures 46.1 and 46.2).

Axial CTPA image.

Figure 46.2 Reformatted coronal CTPA

image.

Question

• What do the CT images demonstrate?

133

ANSWER 46

Figures 46.1 and 46.2 demonstrate axial and reformatted coronal CTPA images respec-

tively, showing a large filling defect within the distal right main pulmonary artery

extending into the upper lobe artery.

The initial chest radiograph in patients with pulmonary embolism is frequently normal.

An initially normal chest radiograph may over time begin to show atelectasis, which

can progress to cause a small pleural effusion and an elevated hemidiaphragm. After

24-72 hours, one third of patients with proven PE develop focal infiltrates that are

indistinguishable from an infectious pneumonia. Occasionally, there may be evidence of

Westermark sign, which is focal oligaemia (absence of blood vessel markings) beyond

the location of the pulmonary embolism and dilatation of those vessels proximally. A

rare late finding of pulmonary infarction is the Hampton hump, a triangular or rounded

pleural-based infiltrate with the apex pointed toward the hilum, frequently located adja-

cent to the diaphragm.

CTPA is the most common study used for detection of pulmonary embolism and has

become accepted both as the preferred primary diagnostic modality and as the standard

for making or excluding the diagnosis of PE. In the majority of patients, multi-detector

CT scans with intravenous contrast can resolve third-order pulmonary vessels.

It is important to note, however, that multi-detector CTPA carries a radiation dose and

can miss lesions in a patient with pleuritic chest pain due to multiple small emboli that

have lodged in distal vessels. In patients with a normal chest radiograph, nuclear scinti-

graphic ventilation-perfusion (V/Q) scanning of the lung is an alternative diagnostic

modality for detecting PE with a lower radiation dose. This modality is recommended

only for patients with a normal chest radiograph in order to prevent spurious perfusion

mismatch from other lung processes.

KEY POINTS

• The initial chest radiograph in patients with PE is frequently normal.

• CTPA is the most common study used for detection of PE and has become accepted

both as the preferred primary diagnostic modality and as the standard for making or

excluding the diagnosis of PE.

• It is important to note, however, that in patients with a normal chest radiograph,

ventilation-perfusion (V/Q) scanning is an alternative modality carrying a lower

radiation dose.

134

CASE 47: A NEW ARRIVAL WITH COUGH AND A FEVER

History

A 40-year-old man arrives in the United Kingdom from Bangladesh to visit relatives.

He has been complaining of feeling generally unwell with a cough and fever for around

3 weeks, which is worsening. He attends the accident and emergency department com-

plaining of a productive cough and feels increasingly systemically unwell with fevers

and sweating. He has has been well previously with no smoking history or history of

exposure to dust.

Examination

His respiratory rate is 24 per minute and pulse 92 per minute. On respiratory examination

there is limited expansion with resonance to percussion, rather quiet breath sounds but

no bronchial breathing and no added sounds. He is febrile with a temperature of 40°C.

Oxygen saturation is 92 per cent breathing air. Full blood count shows a white cell count

of 20 × 10³/mm³.

He is admitted to hospital under the care of the medical team but after a further 24 hours,

the intensive care team are asked to review the patient as his breathing and oxygenation

have deteriorated further. He is intubated and transferred to the intensive care unit where

central lines and a nasogastric tube are inserted. A chest radiograph is performed (Figure

47.1) and, based on this, a computed tomography (CT) scan of the chest was requested

(Figure 47.2).

Figure 47.1 Chest radiograph.

Figure 47.2 Axial CT image.

Questions

• Ignoring the bilateral internal jugular lines, what are the lung changes on the chest

radiograph in Figure 47.1?

• How would you describe the pattern of disease on CT (Figure 47.2)?

135

ANSWER 47

The initial chest radiograph (Figure 47.1) shows diffuse patchy consolidation on a back-

ground of widespread tiny nodules distributed throughout all lobes bilaterally. Subsequent

CT (Figure 47.2) confirms the presence of randomly distributed, diffuse tiny nodules and

bilateral large pleural effusions. Findings are suggestive of miliary tuberculosis.

Miliary tuberculosis (TB) is the widespread dissemination of Mycobacterium tuberculosis

via hematogenous spread. Classic miliary TB is defined as ‘millet like’ (approximately

2 mm) seeding of TB bacilli in the lung, as evidenced on chest radiography. This pattern

is seen in 1-3 per cent of all TB cases.

Following exposure and inhalation of TB bacilli in the lung, a primary pulmonary

complex is established, followed by development of pulmonary lymphangitis and hilar

lymphadenopathy. Mycobacteraemia and haematogenous seeding occur after the primary

infection. After initial inhalation of TB bacilli, miliary TB may occur as primary TB or

may develop years after the initial infection. The disseminated nodules consist of central

caseating necrosis and peripheral epithelioid and fibrous tissue.

Imaging findings may take weeks between the time of dissemination and the radiographic

appearance of disease. Up to 30 per cent have a normal chest radiograph. When first

visible, the nodules measure about 1 mm in size, but they can grow to 2-3 mm if left

untreated. High-resolution CT scans are more sensitive at demonstrating small nodules.

Nodules are either sharply or poorly defined and around 1-4 mm in size in a diffuse,

random distribution. There may be associated intra- and interlobular septal thickening.

Radiographically, nodules are not calcified, as opposed to the initial Ghon focus, which

is often visible on chest radiographs as a small calcified nodule. Chest CT scanning is

useful in the presence of suggestive and inconclusive chest radiography findings. When

treated, clearing is frequently rapid. Under the age of 5 years, there is an increased risk

of meningitis.

Risk factors include immunosuppression, cancer, transplantation, human immunodefi-

ciency virus (HIV) infection, malnutrition, diabetes, silicosis and endstage renal disease.

KEY POINTS

• Miliary TB is caused by the widespread haematogenous dissemination of

Mycobacterium tuberculosis. It is so named because the nodules are the size of millet

seeds (1-5 mm with a mean of 2 mm).

• Miliary TB represents only approximately 1-3 per cent of all cases of TB.

• It is considered to be a manifestation of primary TB, although clinical appearance of

miliary TB may not occur for many years after initial infection.

136

CASE 48: A SEATBELT INJURY

History

A 33-year-old man was a passenger of car involved in a head-on collision travelling at

60 mph (97 km/h). He is brought into the accident and emergency department as a trauma

call. He was sitting in the rear of the car in the central passenger seat restrained by an

old-style ‘lap belt’, unlike the other passengers who were wearing standard shoulder and

lap belts. He was thrown forward into the seat in front. He was conscious throughout but

is complaining of severe pain in the lower thoracic and lumbar spine.

Examination

Primary survey is unremarkable and his observations are stable. There is marked ten-

derness over the lower thoracic and lumbar spine. On neurological examination of the

lower limbs there are no motor or sensory abnormalities. Per rectal examination revealed

normal tone. A computed tomography (CT) examination of the thorax and abdomen was

obtained with sagittal (Figure 48.1a,b) and coronal (Figure 48.1c) reformats.

(a)

(b)

Question

• What abnormality do the CT images

show?

(c)

Figure 48.1 CT scans: (a,b) sagittal and (c)

coronal views.

137

ANSWER 48

The sagittal (Figure 48.1a,b) and coronal (Figure 48.1c) reformats of the spine show a

‘Chance’ fracture line extending through the spinous process, lamina, pedicles and verte-

bral body of T9 (a horizontal splitting of the vertebra beginning with the spinous process

or lamina and extending anteriorly through the pedicles and vertebral body).

Chance fracture is caused by a flexion injury of the spine, first described by G.Q. Chance

in 1948. It consists of a compression injury to the anterior portion of the vertebral body

and a transverse fracture through the posterior elements of the vertebra and the posterior

portion of the vertebral body. It is caused by violent forward flexion, causing distraction

injury to the posterior elements.

Chance fractures later became known as ‘seatbelt’ fractures with the advent of lap seat-

belts in cars. A head-on collision would cause the passenger wearing a lap belt to sud-

denly be flexed at the waist, hence creating significant stress on the posterior elements of

the vertebra. From the 1980s when shoulder and lap belts became more common in cars

Chance fractures have become less associated with road traffic accidents and are more

commonly seen with falls or crush-type injuries where the thorax is acutely hyperflexed.

The most common site at which Chance fractures occur is the thoracolumbar junction and

mid-lumbar region in paediatric populations.

An anterior-posterior (AP) view of the spine may reveal disruption of the pedicles and

loss of vertebral body height. Frequently a transverse process fracture will be identified

on AP projection. The lateral view will demonstrate the spinous process fracture and frac-

tures through the laminae and pedicles. The vertebral body will usually look compressed

and wedge shaped.

CT of the spine should be performed on all Chance fractures to assess the extent of the

fracture and to evaluate the spinal canal. Sagittal reconstructions of the axial images

provide a great deal of information about the fracture pattern. Posterior element fractures

are better seen on lateral projection, although the AP view helps to demonstrate pedicle

involvement.

Up to 50 per cent of Chance fractures have associated intra-abdominal injuries, includ-

ing fractures of the pancreas, contusions or lacerations of the duodenum and mesenteric

contusions or lacerations.

KEY POINTS

• The incidence of associated intra-abdominal injuries with a Chance fracture reaches

50 per cent. Therefore, when a Chance fracture is diagnosed a CT of the abdomen

should be obtained.

• Injuries associated with Chance fractures include fractures of the pancreas, duodenum

and mesentery contusions/rupture.

138

ANSWER 49

The radiograph of the abdomen demonstrates faecal loading of the large bowel but no

significantly dilated loops (Figure 49.1) There is no evidence of free gas or pneumoperito-

neum. Projected over the mid pelvis is an intrauterine contraceptive device (IUCD) (arrow,

Figure 49.2). These are frequently seen as an incidental findings in radiographs of the

abdomen and pelvis. A piercing is also present.

Figure 49.2

The IUCD is a form of birth control. It is an object, placed in the uterus, to prevent

pregnancy. The aim of these devices is to confer long-term, reversible protection against

unwanted pregnancy. They may, however, induce menstrual complications as well as an

increased risk of pelvic inflammatory disease and ectopic pregnancy. They can also be

spontaneously expelled from the uterus without being noticed by the patient.

Among modern IUCDs, the two types available are copper-containing devices and a

hormone-containing device that releases a progestogen. Currently, there are several dif-

ferent kinds of copper IUCDs available in different parts of the world, and there is one

hormonal device, called Mirena®.

An IUCD can increase the risk of spontaneous abortion unless removed in cases where

intrauterine pregnancy occurs. Complications at the time of insertion include pain, syn-

cope and uterine perforation.

In this case, however, the most likely cause of the patient’s abdominal pain is constipa-

tion due to opiate analgesia use and the IUCD is an incidental finding.

KEY POINTS

• Intrauterine contraceptive devices (IUCDs) are a commonly used form of birth control

and are frequently seen as an incidental finding on radiographs.

140

CASE 50: A CARDIAC ABNORMALITY

History

A 66-year-old woman is admitted to the accident and emergency department with sudden

onset of chest pain 1 hour earlier. She had otherwise been fit and well apart from a his-

tory of hypertension for which she had been treated with amlodipine for the last 11 years.

Examination

The electrocardiogram (ECG) shows evidence of left ventricular hypertrophy. Troponin

was not raised. D-dimer was moderately elevated. A chest radiograph was performed

(Figure 50.1). The accident and emergency team were concerned about the possibility

of a pulmonary embolism and therefore a computed tomography pulmonary angiogram

(CTPA) was performed (one axial slice is shown in Figure 50.2). No pulmonary embolism

or focal lung parenchymal abnormality was seen.

Figure 50.1 Chest radiograph.

Figure 50.2 Axial CTPA image.

Question

• What abnormalities do the chest radiograph in Figure 50.1 and axial enhanced CT

image (at the level of the heart) seen in Figure 50.2 demonstrate?

141

ANSWER 50

The chest radiograph (Figure 50.1) demonstrates that the heart is enlarged (there is car-

diomegaly), shown by the fact that the cardiothoracic ratio is greater than 50 per cent

on the posterior-anterior (PA) view. The cardiothoracic ratio is the maximum transverse

diameter of the heart divided by the greatest internal diameter of the thoracic cage (from

inside of rib to inside of rib). This is again demonstrated on the CTPA (in Figure 50.2).

Cardiomegaly is often first detected on chest radiograph.

In normal people the cardiothoracic ratio is usually less than 50 per cent, measured by

taking the maximum transverse diameter of the heart on a PA film as a proportion of the

thoracic diameter at the same level. Therefore, the cardiothoracic ratio is a convenient

way of separating most normal hearts from most abnormal hearts. The heart size should

be assessed on every chest radiograph. On an AP film the cardiac size is magnified so

a ratio over 50 per cent may not indicate cardiac enlargement. If the heart is enlarged,

check for other signs of heart failure such as pulmonary oedema, septal (Kerley B) lines

and pleural effusions.

A multitude of conditions can give rise to cardiomegaly, which is thought to result

from the direct effect of the thickening of the heart muscles when the heart is given an

increased workload. Causative factors include heart valve disorders, high blood pressure,

severe anaemia, thyroid disorders, viral illnesses, drug abuse and previous heart attacks,

which can cause the heart to overwork. An increase in workload, however, may also be

caused by exercise.

KEY POINTS

• If there is cardiomegaly, look for other signs of heart failure.

• Cardiomegaly may be the first sign of an occult systemic or cardiovascular disease.

142

CASE 51: A MIRROR IMAGE

History

A 41-year-old woman was transferred to high dependency unit (HDU) from the general

medical ward where her breathing had been steadily deteriorating. She had been admitted

with a short history of worsening dyspnoea and cough over 2 days. She had demonstrated

pyrexia and raised inflammatory markers and had been treated with high flow oxygen

and antibiotics for a presumed pneumonia but had continued to worsen. The patient was

too unwell to give a medical history but no significant previous medical history had been

noted by the admitting team.

Examination

On examination she is tachypnoic (30/minute) and there is bronchial breathing in both

mid zones with inspiratory crackles in the same areas. Air entry was reduced bilaterally.

On examination for the heart sounds it is noted that they cannot be appreciated in the

normal left praecordial position and the apex beat is also not palpable on the left. Instead

the apex beat is palpated and heart sounds are auscultated on the right of the praecor-

dium. Palpation of the abdomen suggests a liver edge under the left costophrenic angle.

Question

• What condition do you think the patient may have?

• What variations are there?

• What do the chest radiograph (Figure 51.1) and the axial enhanced computed tomo-

graphy (CT) image (Figure 51.2) show.

Figure 51.1 Chest radiograph.

Figure 51.2 Axial enhanced CT image.

143

ANSWER 51

The chest radiograph in Figure 51.1 demonstrates that the heart is positioned within the

right side of the chest (dextrocardia). There is bilateral patchy consolidation within both

lungs, explaining the patient’s respiratory deterioration, and a nasogastric tube inserted

by the HDU team can be seen extending below the right hemithorax instead of the usual

left. The CT scan (Figure 51.2) confirms that the liver and spleen are in opposite positions

to normal, suggestive of situs inversus.

Situs inversus is present in approximately 0.01 per cent of the population. Also called

situs transversus or oppositus, it is a congenital condition in which the major visceral

organs are reversed or mirrored from their normal positions. The term ‘situs inversus’ is a

short form of the Latin phrase situs inversus viscerum, meaning ‘inverted position of the

internal organs’. The normal arrangement is known as situs solitus. In other rare cases, in

a condition known as situs ambiguous or heterotaxy, situs cannot be determined.

In situs inversus, the morphologic right atrium is on the left and the morphologic left

atrium is on the right. The usual pulmonary anatomy is also reversed such that the left

lung has three lobes and the right lung has two. Furthermore, the liver and gallbladder

are located on the left, whereas the stomach and spleen are positioned on the right (as in

the CT shown in Figure 51.2). The remaining internal structures are also a mirror image

of the normal.

Isolated dextrocardia is also termed ‘situs solitus with dextrocardia’. The cardiac apex

points to the right but organs are otherwise in their usual positions. Situs inversus with

dextrocardia is also termed ‘situs inversus totalis’ because the heart position, in addition

to the atrial chambers and abdominal viscera, is a mirror image of the normal anatomy.

The classification of situs is independent of the cardiac apical position.

Approximately 20 per cent of patients with situs inversus have an underlying condition

known as primary ciliary dyskinesia. This is a dysfunction of the cilia, which manifests

during embryonic development. As normal cilia play a role in determining the position of

internal organs during development, these individuals have a higher chance of develop-

ing situs inversus and Kartagener’s syndrome, which is characterized by the triad of situs

inversus, chronic sinusitis and bronchiectasis.

KEY POINTS

• Situs inversus is a congenital condition in which the major visceral organs are reversed

or mirrored from their normal positions.

• When situs cannot be determined, the patient has situs ambiguous or heterotaxy.

In these patients, the liver may be midline, the spleen multiple or absent, the atrial

morphology aberrant and the bowel malrotated. Frequently, normally unilateral

structures are duplicated or absent.

144

CASE 52: A DISTENDED AND PAINFUL ABDOMEN

History

A 72-year-old woman presented to the accident and emergency department with increas-

ing nausea, distension and crampy lower abdominal pain over the previous 2 weeks.

Over a similar time course there has been bright red blood mixed in with her stools and

a slight feeling of incomplete emptying after going to the toilet. There was no history of

vomiting. She was normally very independent and had not wanted to bother her general

practitioner (GP). However, the pain had become increasingly unbearable such that her

husband called an ambulance.

Examination

She looked pale and dehydrated although her observations were all normal apart from

mild postural hypotension. Her abdomen was distended, with generalized tenderness and

voluntary guarding. The bowel sounds were tinkling and upon per rectal examination

there was the impression of a hard mass. Full blood count revealed a mild microcytic

anaemia, with haemoglobin 9.8 g/dL. A plain radiograph of the abdomen was performed

in accident and emergency (Figure 52.1) and on the basis of this the surgical team

requested computed tomography (CT) imaging (Figures 52.2 and 52.3).

Figure 52.2 Axial CT scan.

Figure 52.1 Plain radiograph.

Question

• What does the plain radiograph demon-

strate?

• What is the differential diagnosis?

• What do the axial CT images show?

Figure 52.3 Axial CT scan.

145

ANSWER 52

Figure 52.1 demonstrates multiple loops of dilated large bowel filling the abdomen con-

sistent with a distal mechanical large bowel obstruction or pseudo-obstruction (note the

radiograph is suboptimal as the upper abdomen has been missed). Figure 52.2 shows an

axial contrast enhanced CT image on lung windows at the level of the adrenal glands

demonstrating multiple dilated loops of large bowel distending the abdomen. Figure 52.3

with soft tissue CT windows demonstrates a large obstructing, circumferential bulky rec-

tal mass as the cause of the large bowel obstruction.

The most common causes of mechanical large bowel obstruction in this age of patient

would include colon cancer, diverticulitis or sigmoid volvulus. Less common causes

of large bowel obstruction include inflammatory bowel disease, hernias, adhesions or

endometriosis.

Approximately 25 per cent of all intestinal obstructions occur in the large bowel. Large

bowel obstruction is a common emergency condition that requires early identifica-

tion and intervention and may result from either mechanical interruption of the flow

of intestinal contents or by the dilation of the colon in the absence of an anatomic

lesion (pseudo-obstruction). Distinguishing between a true mechanical obstruction and a

pseudo-obstruction is important as the treatment differs.

Radiologically, the large bowel is characterized on plain film by its haustrations and

sacculations, which are most prominent in the ascending and transverse colon but can

also be seen in the left colon. With moderate distention of the large bowel, the haustral

folds appear to extend entirely across the lumen but this appearance may disappear with

further distension. The haustral folds of the large bowel are more widely spaced than the

valvulae conniventes of the small bowel. The large bowel will normally contain solid

material, whereas small bowel usually contains liquid and gas only. Furthermore, large

bowel tends to be peripherally located, whereas the small bowel is centrally located.

The colon is dilated when it exceeds 6 cm in diameter, and the caecum is dilated when

it exceeds 9 cm. When the caecal diameter exceeds 10 cm the risk of perforation is high.

The caecum always dilates to the largest extent no matter the location of large bowel

obstruction.

Gas and faeces tend to accumulate proximal to the point of obstruction. In a typical

configuration of mechanical obstruction, all colonic segments proximal to the point of

luminal narrowing are dilated. In most cases of large bowel obstruction, the bowel will

contain variable amounts of solid, liquid and gaseous constituents. CT imaging frequently

identifies the cause of obstruction.

KEY POINTS

• Dilatation of the colon >6 cm is abnormal (as is caecal dilatation >9 cm).

• An abdominal radiograph may demonstrate the level of large bowel obstruction but

cannot reliably differentiate mechanical obstruction from pseudo-obstruction.

146

ANSWER 53

In the chest radiograph (Figure 53.1) there is diffuse haziness over the left hemithorax

which is caused by the collapse (atelectasis) of the left upper lobe which lies as a thin

curtain over the remaining inflated left lower lobe. There is a left hilar mass, which is

the likely cause for the lobar collapse. On the axial enhanced CT image (Figure 53.2) an

obstructing left hilar mass is seen along with an adjacent parenchymal mass.

It is important to be aware that the left upper lobe does not collapse in the same manner

as the right upper lobe. This is due to anatomy as there is no middle lobe on the left. The

equivalent of the right middle lobe on the left is the lingula segment of the left upper

lobe.

Plain film signs of left upper lobe collapse include: an area of increased opacity in the

left upper lobe with a poorly defined margin on posterior-anterior (PA) radiograph, the

left hilum may be elevated and an increase in lung density which may be almost imper-

ceptible on the PA view. The aortic knob and upper left cardiac shadow may be obliter-

ated and there may be a lucent stripe between the medial edge of the collapsed segment

and the aortic arch (where the lower lobe has been pulled up by the collapsed lung - the

Luftsichel sign). Unlike right upper lobe collapse, there is no sharply defined border and

the abnormal increase in lung density merges into the normal lung inferiorly.

Lobar collapse is divided physiologically into obstructive and non-obstructive causes.

Obstructive atelectasis is the most common form and results from reabsorption of gas

from the alveoli when communication between the alveoli and the trachea is obstructed.

The obstruction can occur at the level of the larger or smaller bronchus. Common causes

of obstructive atelectasis include foreign body, tumour and mucous plugging.

Non-obstructive atelectasis can be caused by loss of contact between the parietal and

visceral pleurae, compression, loss of surfactant and replacement of parenchymal tissue

by scarring or infiltrative disease.

Collapse and consolidation can occur independently or together. Collapse can be partial

or complete. Consolidation alone is not associated with a reduction in volume of the

affected lung. It is often not clear to what extent the appearance is due to collapse or

consolidation or both. If a lobe is only partially collapsed and there is no accompanying

consolidation, there may be no increase in opacity. In cases of pure collapse, only when

the collapse is virtually complete will there be a significant increase in density of the

affected lung.

KEY POINTS

• Left upper lobe collapse may be a subtle finding on chest radiograph.

• In the context of the clinical history, given this is highly suspicious for collapse

secondary to an obstructing bronchogenic malignancy further imaging with CT should

be performed for further evaluation.

148

ANSWER 54

Figure 54.1 is an ultrasound image demonstrating an ovoid hypoechoic subcutaneous

lesion parallel to the skin with no evidence of invasion into deeper structures. There are

septations seen internally. Sonographic features are consistent with a lipoma. The same

lesion with colour Doppler settings applied (Figure 54.2) shows that the lesion is avascu-

lar, consistent with a lipoma.

Lipomas are the most common benign mesenchymal tumour. These slow-growing, benign

fatty tumours form soft, lobulated masses enclosed by a thin, fibrous capsule. Although

it has been suggested that lipomas may rarely undergo sarcomatous (malignant) change,

this has never been convincingly proven. The majority of lipomas encountered by

clinicians are subcutaneous in location. Lipomas typically develop as discrete rubbery

masses in the subcutaneous tissues of the trunk and proximal extremities. Occasionally

they may be found in other locations, for example, intramuscular, retroperitoneal and

gastrointestinal.

Patients usually give a history of a slowly growing lesion present for years and usually do

not complain of pain or discomfort. Painful lipomas are the hallmark of a rare condition

called Dercum’s disease (adiposis dolorosa).

In the subcutaneous location, the primary differential diagnosis is a sebaceous cyst or an

abscess. Sebaceous cysts are also rounded and subcutaneous. They can be differentiated

from lipomas by their characteristic central punctum and the surrounding induration.

Treatment requires removal of a small ellipse of overlying skin to avoid entering the cyst.

Abscesses typically have overlying induration and erythema. In these cases, incision and

drainage is the appropriate management.

On ultrasound, subcutaneous lipomas are usually seen as well-defined, compressible,

elliptical masses with the longest diameter parallel to the skin surface. They demon-

strate multiple echogenic lines parallel to the skin surface with no evidence of posterior

enhancement or attenuation and no flow on colour Doppler sonography (as seen in

Figure 54.2). Compared with adjacent muscle, most lipomas are hyperechoic (bright), but

some may be isoechoic or hypoechoic (dark).

CT scanning is principally indicated for distinguishing between lipomas and liposarcomas.

KEY POINTS

• Subcutaneous lipomas are common, slow-growing, benign soft tissue tumours.

• Sonographically they are usually seen as well-defined, avascular, compressible,

elliptical masses with the longest diameter parallel to the skin surface.

150

CASE 55: ABDOMINAL DISTENSION AND SHIFTING DULLNESS

History

A 61-year-old man presents to hospital with generalized abdominal distension and bloat-

ing over the previous 3 weeks. This has become increasingly uncomfortable. He also notes

feeling tired and lethargic.

Examination

Upon examination his observations are all within normal limits. His chest is clear but the

abdomen is markedly distended. Upon percussing the abdomen there is dullness which

moves depending on the position of the patient (shifting dullness). Bowel sounds are

present but reduced. Rectal examination reveals an empty rectum.

His haemoglobin is reduced at 9.6 g/dL with evidence of a microcytic anaemia. Otherwise

his blood biochemisty, liver function test and inflammatory markers are normal.

An ultrasound was performed in the first instance (Figure 55.1) and on the basis of this

a computed tomography (CT) was done (Figure 55.2).

Figure 55.1 Ultrasound.

Figure 55.2 CT scan.

Questions

• What do the ultrasound image and the CT image demonstrate?

• What are the potential causes that could give rise to this?

151

ANSWER 55

The ultrasound image in Figure 55.1 demonstrates a large, anechoic (in other words, no

echoes or solid component) fluid collection within the abdomen. The edge of the liver is

seen in the bottom left of the image and collapsed loops of bowel are seen inferiorly and

to the right. The ultrasound image has been acquired with the probe held in a longitudinal

orientation in the subphrenic region.

The axial contrast enhanced CT image in Figure 55.2 confirms a large volume of fluid

around the inferior margin of the liver, the spleen and within the upper abdomen.

Ascites describes the condition of pathological collection of fluid within the abdominal

cavity and there is a wide differential of both transudative and exudative causes.

Uncomplicated (in other words non-infected, inflammatory or malignant) ascites appears

as a homogeneous, freely mobile, anechoic collection in the peritoneal cavity demonstrat-

ing acoustic enhancement. Free ascites does not displace organs but typically distributes

itself between them, conforming to organ margins.

Features suggesting complicated ascites include fine or coarse internal echoes, septation,

loculation or atypical fluid distribution, matting/clumping of bowel loops and thickening

of interfaces between the fluid and adjacent structures.

Traces of fluid usually collect in the posterior subhepatic space (Morrison’s pouch) and

around the liver as a sonolucent (dark on ultrasound) band. Fluid also often localizes in

the pouch of Douglas (recto-uterine pouch). Where there is a large volume of ascites, the

small bowel loops have a characteristic appearance on ultrasound as they hang from a

vertically floating mesentery.

Ascites is also usually demonstrated well on CT scanning. CT may also demonstrate the

aetiology including features suggestive of neoplasia such as hepatic, splenic or adrenal

lesions, lymphadenopathy or masses arising from the bowel, ovary or pancreas.

This patient was found to have a gastrointestinal stromal tumour as the cause of his

ascites.

KEY POINTS

• Ultrasound and CT are both sensitive to small volumes of ascites and may demonstrate

the aetiology.

152

CASE 56: A PAINFUL HAND

History

A 55-year-old woman presents to her general practitioner (GP) with several weeks of

pain in the left hand. She remembers tripping in the garden and landing on her left out-

stretched hand previously but had not attended the accident and emergency department,

as she did not feel she had sustained a fracture.

She is otherwise fit and well. Her symptoms include pain (which she describes as ‘burn-

ing’ type), tenderness and swelling in the left hand.

Examination

On examination there is wasting of the intrinsic muscles of the hand associated with evi-

dence of sweating, warmth and flushed, shiny skin. There was evidence of hyperaesthesia,

hyperalgesia and allodynia. There was no evidence of synovitis or deformity, however.

The GP decided to refer the patient to her local hospital for an X-ray (Figures 56.1a,b).

(b)

Figure 56.1 (a) Posterior-anterior (PA) and (b) oblique views.

Question

• What abnormality do you notice on these hand radiographs?

153

ANSWER 56

There is diffuse reduction in radiological bone density (increased radiolucency) in a pre-

dominantly periarticular distribution around the joints of the hand. There is, however, no

associated evidence of joint erosions or destruction and no focal destructive cortical bony

lesion or periosteal reaction is seen. Features are consistent with a regional periarticular

osteopaenia.

Osteopaenia refers to reduced bone mineral density and, radiologically, to increased

radiolucency of bone. The most common cause by far of osteopaenia is osteoporosis,

however, there are multiple aetiologies so the finding of radiolucent bone does not make

this an automatic diagnosis. One should search for other more specific clues to the exact

underlying disorder and more specific radiographic clues to their diagnosis.

Osteopaenia can be difficult to diagnose accurately on plain radiographs which are fre-

quently insensitive to changes in bone mineral. Approximately 30-50 per cent of the

bone mass must be lost before it can be detected on a plain film.

Osteopaenia may be diffuse or regional and the differential diagnosis is broad and can

be vascular, drug-induced, toxic, endocrine/metabolic, congenital or idiopathic. Causes

of regional osteoporosis include immobilization with disuse and regional sympathetic

dystrophy syndrome (RSDS).

In the hand radiographs seen in Figures 56.1, the joint spaces are generally preserved

with no destructive changes. The history, examination and imaging features suggested

regional osteoporosis secondary to RSDS.

The exact mechanism of how RSDS develops is poorly understood. Theories include irri-

tation and abnormal excitation of nervous tissue, leading to abnormal impulses along

nerves that affect blood vessels and skin. A variety of events can trigger the condition,

including trauma, surgery, heart disease, degenerative arthritis of the neck, stroke or

other brain diseases, nerve irritation by entrapment (such as carpal tunnel syndrome),

shoulder problems, breast cancer, and drugs for tuberculosis and barbiturates. The inci-

dence after fractures and contusions ranges from 10 to 30 per cent. In this case the

patient had sustained trauma in the absence of a fracture. While some cases are associ-

ated with an identifiable nerve injury, many are not and there is no associated event in

a third of patients. The upper extremities are more likely to be involved than the lower.

KEY POINTS

• Osteopaenia refers to increased radiolucency of bone. The most common cause by far

of osteopaenia is osteoporosis.

• Osteopaenia can be diffuse or localized. Secondary clues should be sought to identify

the aetiology.

154

CASE 57: A RETIRED CONSTRUCTION WORKER WITH A COUGH

History

A 65-year-old retired construction worker attends his general practitioner (GP) with a

cough. The cough was non-productive and he denied feeling significantly short of breath.

He also denied fevers and weight loss. He was a non-smoker and had been otherwise

well aside from taking a thiazide diuretic for hypertension, which was well controlled.

He had only a history of hernia repair and appendicectomy many years previously. In his

occupational history, he had retired from construction work aged 50 and had worked in

an administrative role for the last 15 years.

Examination

On examination he looked well. There was good air entry and chest expansion bilaterally,

breath sounds were vesicular and there were no added sounds.

A routine chest radiograph was performed (Figure 57.1). Upon reviewing the radiograph

the GP requested a computed tomography (CT) scan of the thorax (Figure 57.2).

Figure 57.1 Chest radiograph.

Figure 57.2 CT scan of thorax.

Questions

• What do the chest radiograph and the CT scan demonstrate?

• What may cause this appearance?

155

ANSWER 57

The chest radiograph in Figure 57.1 demonstrates multiple bilateral radio-opaque pleural

plaques consistent with previous exposure to asbestos. This is confirmed on CT in Figure

57.2 where calcified pleural plaques are seen along the diaphragmatic pleura.

Pleural plaques are deposits of hyalinized collagen fibres in the parietal pleura. They are

indicative of asbestos exposure and typically become visible after a latency period of

10-20 or more years after the inhalation of asbestos fibres. Asbestos is a naturally occur-

ring fibrous silicate that was widely used in the past for a range of commercial applica-

tions including shipbuilding, construction, textile and insulation industries.

In addition to benign pleural plaques, however, there is also a spectrum of more significant

asbestos-related thoracic diseases including benign pleural effusion, diffuse pleural thicken-

ing, rounded atelectasis, asbestosis (i.e. lung fibrosis), mesothelioma and lung cancer. Plaques

may occur in isolation as in this case or in association with lung parenchymal disease.

Pleural plaques are usually multiple, bilateral and often relatively symmetrical and are

located in the mid portion of the chest wall between the seventh and tenth ribs, following

rib contours, or adjacent to the aponeurotic portion of the diaphragm (as seen on the CT).

Visceral pleura, lung apices and costophrenic angles are usually spared.

On chest radiographs, the prevalence of calcification in pleural plaques is reported to be around

15 per cent, however CT is far more sensitive with sensitivity around 50 per cent. In profile, cal-

cified plaques appear as opaque lines that lie parallel to the chest wall, mediastinum, pericar-

dium and diaphragm. Viewed en face, calcified plaques are seen as irregular and heterogeneous

densities. The presence of bilateral, superior diaphragmatic surface calcifications with spared

costophrenic angles is virtually pathognomonic for asbestos-related pleural disease. Isolated

plaques and diffuse pleural thickening may also seen in tuberculosis, trauma and haemothorax.

CT scanning is often used in the evaluation of pleural disease. Plaques appear as discrete,

well-defined areas of localized pleural thickening which are usually multiple, bilateral

and located adjacent to rigid structures, such as the ribs, mid portion of the chest, apo-

neurotic portion of the diaphragm, mediastinum and paravertebral regions. Lung apices

and costophrenic angles typically are spared. Rarely, the visceral pleura within fissures

may be involved, or plaques may be pedunculated.

CT scanning (in particular, high-resolution CT) allows demonstration of interstitial infil-

trates and fibrosis, and may be helpful in diagnosing early stages of asbestosis. It also

is useful in delineation of pleural or pleura-based abnormalities (for example, effusion,

thickening, plaque, malignant mesothelioma, rounded atelectasis) and in evaluation of a

parenchymal density that is suggestive of bronchogenic carcinoma.

In this case, the CT failed to show any further significant sequelae of asbestos exposure and the

patient recovered with a short course of antibiotics. In the absence of any other sign of asbestos-

related disease, isolated pleural plaques alone do not require further follow-up or investigation.

KEY POINTS

• Latency time for development of pleural plaques is usually around 20 years.

• Most patients who have asbestos-related pleural plaques are asymptomatic. The

chest radiograph plays an important role in detection of asbestos-related pleural and

parenchymal abnormalities and assessment of progression of disease.

• High-resolution CT is superior to the radiograph in detection of pleural plaques and is

more sensitive and specific for the diagnosis of asbestos-related pleural disease.

156

CASE 58: DISTENDED ABDOMEN AND UNABLE TO PASS GAS

History

A 38-year-old man attends the accident and emergency department with a 48-hour

history of cramping abdominal pain associated with nausea and vomiting. He felt his

abdomen was ‘blown up’ and mentioned no longer being able to pass flatus. He was also

sweating and thirsty.

Five years previously he had a prolonged admission following a perforated appendix for

which he had his appendix removed and an associated abscess drained. He had remained

well ever since, took no medications and had no allergies.

Examination

On examination his pulse was 104/minute, in sinus rhythm. His mucous membranes were

dry. His abdomen was distended. He complained of generalized tenderness but there was

no rebound or guarding. The bowel sounds were prominent and tympanic. Per rectal

exam demonstrated an empty rectum.

His blood results demonstrated normal inflammatory markers. His biochemistry revealed

a urea of 8.4 mmol/L but creatinine within the normal range.

An erect chest radiograph was performed which did not demonstrate any free subdia-

phragmatic gas, but the abdominal radiograph (Figure 58.1) was abnormal. In light of

this and following surgical review, a computed tomography (CT) scan was performed

(Figure 58.2).

Figure 58.1 Abdominal radiograph.

Figure 58.2 CT scan.

Questions

• What abnormality is seen on the plain abdominal radiograph (Figure 58.1)?

• What does the CT show (Figure 58.2)?

• What does the arrow point to?

157

ANSWER 58

The radiograph of the abdomen in Figure 58.1 demonstrates multiple abnormally distended

loops of small bowel. No surgical clips are seen. The large bowel is collapsed. It is possible

to determine that this is small bowel dilatation, by the central location, calibre and the

presence of valvulae conniventes (as opposed to the peripheral location, wider calibre and

haustral folds of the large bowel). There is no evidence of pneumoperitoneum to suggest

perforation. The axial CT in Figure 58.2 confirms dilated loops of fluid-filled small bowel.

A small bowel obstruction is caused by a variety of pathologic processes but essentially

is due to mechanical obstruction to the passage of the bowel contents somewhere in the

small bowel. The bowel proximal to the point of obstruction dilates with swallowed air

and secreted fluid. Vomiting may release some of the proximal bowel contents and reduce

the amount of proximal dilation. Bowel distal to the point of obstruction (i.e. colon and

distal small bowel) empties and collapses over time

The leading cause in developed countries is postoperative adhesions

(60 per cent).

Postoperative adhesions can be the cause of acute obstruction within weeks of surgery or

present as chronic obstruction years later as in this case.

The second most common identified cause of small bowel obstruction is an incarcerated groin

hernia. Other aetiologies include malignant tumor (20 per cent), other hernias (10 per cent),

inflammatory bowel disease (5 per cent), volvulus (3 per cent) and other causes (2 per cent).

Small bowel obstructions can be partial or complete. They may also be simple or strangu-

lated. Strangulated obstructions are surgical emergencies. If not diagnosed and properly

treated, vascular compromise can lead to bowel ischaemia, morbidity and mortality.

Plain radiographs are the primary imaging modality with the sensitivity reported as

approximately 75 per cent. Assessment should be made for surgical clips (which may

suggest adhesions as a cause), the hernial orifices (for incarcerated hernia) or aerobilia/

calcific densities (possible gallstone ileus). Small bowel dilatation greater than 2.5-3 cm

(especially if there is evidence of air-fluid levels) indicates small bowel obstruction.

CT scanning is useful in distinguishing extrinsic causes, for example adhesions and hernias,

from intrinsic causes, such as neoplasms or Crohn’s disease. A transition point may be iden-

tified localizing any focal adhesions, as seen on the axial CT image in Figure 58.2 (arrow),

which cannot be appreciated on plain films. The patient in this case probably developed

adhesions as a consequence of the surgery for his perforated appendix and abscess drainage.

CT should be considered where the patient has fever, tachycardia and localized abdomi-

nal pain with raised inflammatory markers. CT may demonstrate abscesses, inflamma-

tory processes, extraluminal pathology resulting in obstruction, tumours or mesenteric

ischaemia. It also allows discrimination between ileus and mechanical small bowel in

postoperative patients.

KEY POINTS

• In cases of small bowel obstruction, plain radiographs are the primary imaging

modality and assessment should be made for surgical clips (which may suggest

adhesions), hernial orifices (for incarcerated hernia) or aerobilia/calcific densities

(possible gallstone ileus).

• CT scanning is useful in distinguishing the aetiology and also allows discrimination

between ileus and mechanical small bowel in postoperative patients.

158

CASE 59: TORRENTIAL HAEMATEMESIS

History

A 52-year-old man with a history of alcoholism and hepatitis C is admitted to intensive

care with torrential haematemesis. He requires the transfusion of 10 units of blood, clot-

ting factor and platelets over 36 hours. Upper gastrointestinal endoscopy reveals large

clots seen within the stomach with an associated bleeding point as a result of varices.

Examination

The patient is tachycardic with a pulse rate of 108/minute and tachypnoeic at 22/minute.

His blood pressure has been maintained within normal limits with replacement of blood

and colloids. Despite best efforts, however, the endoscopist is unable to halt the gastric

bleeding and a computed tomography (CT) scan is therefore performed to assess for any

potential point of arterial embolization (Figure 59.1a,b).

(a)

(b)

Figure 59.1 Two axial contrast-enhanced CT images.

Question

• What abnormalities do the two axial contrast-enhanced CT images in Figure 59.1a,b

demonstrate?

159

ANSWER 59

The axial contrast-enhanced CT images in Figure 59.1 are taken at two levels through the

upper abdomen and demonstrate the presence of enhancing serpigenous veins adjacent to

the stomach consistent with gastric varices as a consequence of liver cirrhosis (irregular

liver contour, patchy low attenuation and enhancement) and portal venous thrombosis

(filling defect within the portal vein), which are also seen.

Gastric varices are dilated submucosal veins in the stomach, which are most frequently

found in patients with portal hypertension and resulting elevated portal venous pres-

sure, which may be a complication of cirrhosis. In this example, the portal vein itself is

thrombosed.

Gastric variceal bleeding is often profuse, has a high rate of recurrence and is associated

with decreased survival. Bleeding varices represent a potentially life-threatening cause

of haematemesis.

In the setting of cirrhosis and portal hypertension, gastric varices are usually associated

with oesophageal varices. Isolated gastric varices may also be found in patients with

splenic venous thrombosis as blood is shunted via the short gastric veins, which drain

the fundus of the stomach flow. For example, this may be a complication of acute pan-

creatitis or pancreatic malignancy.

Patients with bleeding gastric varices in addition to presenting with haematemesis, may

exhibit melaena or frank rectal bleeding. The bleeding may be brisk, and patients may

soon develop haemorrhagic shock, with this patient clinically demonstrating features of

grade 2 shock.

Gastric varices are seen on CT (Figure 59.1) as characteristically multiple lobulated, ser-

pentine masses. It is possible for varices to present as a polypoid mass in the fundus.

They may also be seen on ultrasound of the upper abdomen or on upper gastrointestinal

barium series (although they may be obscured by overlying gastric rugae).

On this occasion, no focal bleeding point was identified as suitable for embolization.

KEY POINTS

• CT or ultrasound may demonstrate evidence of liver cirrhosis, portal hypertension and

ascites in addition to the varices themselves.

160

CASE 60: AN INCIDENTAL FINDING ON CHEST RADIOGRAPH

History

A previously fit and well 16-year-old boy attends his general practitioner (GP) with a

2-week history of a cough. He noted a small amount of clear sputum but the cough had

been generally non-productive and there had been no blood expectorated. He had noted

feeling generally feverish. He had been previously fit and well.

Examination

On examination he demonstrates evidence of an upper tract respiratory infection. He was

afebrile, with a respiratory rate of 20/minute and a heart rate of 80/minute. On respiratory

examination there is equal lung expansion with good air entry bilaterally. Breath sounds

were vesicular with no added sounds. Investigations showed a normal white cell count

and a slightly elevated C-reactive protein of 20 mg/L. Blood biochemistry was normal.

The GP referred him to his local hospital for a chest radiograph (Figures 60.1 and 60.2).

Figure 60.1 Chest radiograph

Figure 60.2 Chest radiograph

Questions

• What do you observe about the chest radiograph (Figure 60.1)?

• What do the arrows identify (Figure 60.2)?

• What is the significance of this finding?

161

ANSWER 60

Figure 60.1 shows a normal heart size and mediastinal contour with no focal collapse,

consolidation or active pulmonary lesion. The pleural spaces are clear. Incidental note is

made of an azygos fissure.

The arrows in Figure 60.2 identify an azygos fissure (azygos lobe), which is a small acces-

sory lobe sometimes found on the upper part of the right lung, separated from the rest of

the upper lobe by a deep groove lodging the azygos vein, of little clinical significance.

The azygos lobe appears commencing in a ‘teardrop’ shape approximately at around the

level of T5 to the right of the midline as a pale line curving outward and upward, then

back in to meet the root of the neck. The line is the infolding of the pleura.

Abnormal fissures and lobes of the lungs are common and usually insignificant. A lobe

related to the azygos vein appears in the right lung in about 1-2 per cent of people. It

develops when the apical bronchus grows superiorly and medial to the arch of the azygos

vein (instead of lateral to it). As a consequence, the azygos vein comes to lie at the bottom

of a deep fissure in the superior lobe of the right lung.

In this patient, no focal active lung pathology was identified. Incidental note was made

of the azygos lobe. No further investigation or treatment is required.

KEY POINTS

• An azygos lobe is frequently an incidental finding on chest radiograph and usually has

no clinical significance.

162

CASE 61: A WORRIED NURSE IN INTENSIVE CARE

History

A 64-year-old man is admitted to intensive care following a coronary artery bypass graft

and aortic valve replacement. The procedure was uncomplicated, but post-operatively he

is slow to regain his appetite and a nasogastric tube is placed on intensive care for enteral

feeding. The nurse uses litmus paper to test the acidity of the aspirates and is concerned.

Simultaneously, the patient shortly afterwards begins to become dyspnoeic and is making

gagging reflexes.

Examination

His saturations drop to 82-86 per cent on 8 L of oxygen. His blood pressure and heart rate

remain within normal limits. A chest radiograph is performed urgently (Figure 61.1).

Figure 61.1 Chest radiograph.

Questions

• What abnormality do you note on the chest radiograph in Figure 61.1?

• What other findings are there on the image?

• What has changed in Figure 61.2?

• What abnormality does Figure 61.3 show (taken from a different paediatric patient)?

Figure 61.2 Later chest radiograph.

Figure 61.3 Chest radiograph from a different

(paediatric) patient.

163

ANSWER 61

The chest radiograph in Figure 61.1 shows that the nasogastric (NG) tube has been passed

down the left main bronchus. This is unusual as the (less acute) angle of the right main

bronchus is usually more favourable. There is a right internal jugular catheter which

is appropriately placed with its tip projected over the superior vena cava/right atrium.

A left intercostal chest drain is seen. Sternal wires are noted. Figure 61.2 demonstrates

the appropriately repositioned NG tube extending below the diaphragm. Figure 61.3

demonstrates an NG tube in a different (paediatric) patient, which lies within the distal

oesophagus and should be advanced into the stomach.

Chest radiographs for NG tube position are common. The NG tube is usually inserted

either for providing enteral nutrition, administration of drugs or for gastric drainage.

Nasogastric feeding is a common practice in all age groups. There is a risk that the NG

feeding tube can be misplaced into the lungs during insertion (as in Figure 61.1) or may

move out of the stomach at a later stage (Figure 61.3).

In the past, various methods have been used to determine the position of NG feeding

tubes. These included:

• auscultation of air insufflated through the feeding tube (listening for a ‘whoosh’);

• testing acidity or alkalinity of the aspirate using litmus paper;

• looking for bubbling at the end of the NG tube;

• the appearance of the feeding tube aspirate.

Current recommendations, however, suggest that these measures are not reliable and

therefore should not be used to detect the position of NG tubes.

The position of the tip of the NGT is assessed frequently in the first instance by drawing

back gastric contents and testing with pH paper. If there is any concern then radiographic

confirmation of NG tube position is performed.

Indeed current guidelines suggest:

• measuring the pH of the aspirate using pH indicator strips;

• use of radiography.

The most accurate method for confirming the correct position of an NG feeding tube is

radiography. The aim of radiography is to positively confirm that the NG tube is within

the gastrointestinal tract (within the stomach).

Sometimes longer nasojejunal (NJ) tubes are used. The objective is to place the tip of the

tube past the pylorus, through the duodenum and beyond the duodenal-jejunal flexure

into the jejunum. In doing so, this bypasses the regulatory function of the pylorus and

delivers nutrition or therapeutic agents directly into the jejunum.

The importance of establishing the position of the NG tube cannot be understated. A

patient who is fed or administered drugs via a malpositioned NG tube, such as that in

Figure 61.1, can deteriorate significantly and it may even lead to iatrogenic death.

KEY POINTS

• Current guidelines for appropriate placement of NG tubes include measuring the pH of

the aspirate using pH indicator strips and use of chest radiography to ensure the tip of

the tube is sited appropriately.

164

CASE 62: YOUNG MAN WITH ABDOMINAL PAIN

History

A 24-year-old man presents to the accident and emergency department with vomiting

and abdominal pain that has been worsening over the last 24 hours. He describes initially

feeling unwell with mild fever and central abdominal discomfort that has slowly focused

into the right iliac fossa. He has not been exposed to other people with similar symptoms

and although he has bought and eaten freshly prepared food, none of his friends have

has similar symptoms. He has no significant medical history.

Examination

His temperature is 37.8°C but his observations are otherwise normal. His chest and heart

sounds are normal. On abdominal examination there is mild distension and tenderness

over the right iliac fossa but no rebound tenderness. Bowel sounds are reduced.

You arrange an abdominal radiograph (Figure 62.1) and an ultrasound (Figure 62.2),

among other tests.

Figure 62.1 Abdominal radiograph.

Figure 62.2 Ultrasound image of the right

iliac fossa.

Questions

• What do the investigations show?

• What differential diagnoses could give these appearances?

• What else would you like to know?

• Would you do more imaging?

165

ANSWER 62

The abdominal radiograph (Figure 62.1) shows dilated lucent loops of small bowel, likely

to be partially gas filled in the upper abdomen. The distal small bowel is not seen, prob-

ably fluid filled and no comment about dilatation can be made. The large bowel gas pat-

tern is not abnormal. The appearance could indicate a small bowel ileus or obstruction,

although a transition point to indicate a mechanical obstruction is not seen.

The ultrasound of the right iliac fossa (Figure 62.2) shows a tubular structure measuring

1.3 cm containing a calcification that blocks the ultrasound beam and casts a shadow

that may represent a dilated appendix (>6 mm diameter). The upper abdomen is normal.

The bladder appears normal. No significant free fluid is seen.

The differential diagnosis includes appendicitis, mesenteric adenitis (usually children),

gastroenteritis, Crohn’s disease, urinary tract infection and, in women, ovulation pain,

ovarian cyst haemorrhage, torsion, ectopic pregnancy and pelvic inflammatory disease.

Appendicitis seems the most likely diagnosis, however tests should include urinalysis. In

women, a pregnancy test should be done and it can be difficult to entirely rule out ovar-

ian causes or pelvic inflammatory disease and a transvaginal ultrasound may be helpful

although may not be acceptable in younger females. The diagnosis may end up being

primarily clinical although a computed tomography (CT) may be done (as in this case due

to the dilated small bowel) if it is considered that the additional information justifies the

X-ray dose (Figure 62.3).

Appendicitis with small bowel dilatation is associated with a higher incidence of perfora-

tion of the appendix.

(a)

(b)

Figure 62.3 (a) Oblique axial and (b) coronal CT slices of the abdomen and pelvis showing a

large appendicolith (present in 25 per cent on CT) within the dilated appendix (white arrows)

with surrounding inflammatory change of the fat and caecal pole.

KEY POINTS

• Ultrasound may occasionally diagnose appendicitis but may struggle to rule out many

of the differential diagnoses.

• Ultrasound may be useful where there is reasonably high suspicion for appendicitis in

children and young women where a CT scan may be avoided.

166

CASE 63: SKIN PLAQUES AND ACHY HANDS

History

A 41-year-old woman is referred to the outpatient rheumatology clinic complaining of

painful joints. The symptoms have been longstanding for 4 months and intermittently

cause an achy pain in the finger joints of both hands. This is sometimes associated with

joint swelling and causes stiffness, which is constant and not worse at any particular time

of the day. She denies any stigmata of infection, weight loss or rash.

Approximately 5 years ago she was diagnosed with psoriasis for which she takes topical

coal tar which controls her skin plaques well. She has no other relevant past medical

history and does not take any other regular medication. She finds her job as a nursery

school teacher very rewarding, but is finding her fine motor skill inhibited by joint

stiffness when trying to help the children in arts and crafts lessons. She is a smoker of

approximately 10 per week and drinks at weekends only. She is unmarried but lives with

her boyfriend.

Examination reveals mildly swollen proximal interphalangeal joints bilaterally, which are

tender and have slightly limited range of movement. Bloods are taken and a radiograph

of both hands is ordered (Figure 63.1).

Figure 63.1 Anterior-posterior (AP) radiograph of both hands.

Questions

• What does the radiograph demonstrate?

• What is the main differential for these appearances?

• What are the extra-articular manifestations of rheumatoid arthritis?

167

ANSWER 63

Figure 63.1 is an AP radiograph of both hands in an adult female patient. Soft tissue swelling

is seen involving the proximal interphalangeal joints (PIPJs). There is a symmetrical distal

small joint polyarthropathy. This predominantly involves the second, third and fourth PIPJs

of both hands with less marked involvement of the first interphalangeal joints and the distal

interphalangeal joints (DIPJs). The involved joints demonstrate loss of normal cartilage and

reduced joint space with marginal juxta-articular erosions. These are poorly demarcated and

partially obscured with overlying new bone formation, suggesting periostitis, and are termed

‘proliferative erosions’. The PIPJ articular surfaces are irregular, but there is no subperiosteal

osteoporosis or articular erosive changes seen to suggest a ‘pencil in cup’ appearance.

Bone density is preserved throughout and there is no bony ankylosis. The metacarpo-

phalangeal joints are preserved, but there is mild radiocarpal and carpometacarpal joint

space narrowing in keeping with degenerative change. These appearances are character-

istic of a seronegative spondyloarthropathy most likely related to psoriasis, however a

diagnosis of rheumatoid arthritis needs to be excluded.

Psoriasis is a chronic inflammatory skin condition, which can affect people at any age.

It is characterized by the presence of red skin plaques that are raised from the skin and

is often capped by silvery scales, associated with nail changes. It has a predilection for

extensor sites and is most commonly identified at the elbow and knee joints. There are

well-documented extracutaneous manifestations with arthropathy affecting 5 per cent

of psoriatic suffers and sometimes preceding the skin plaques by many years. There five

radiological subtypes of psoriatic arthropathy:^1,2

• symmetrical polyarthritis of the interphalangeal joints;

• seronegative polyarthritis mimicking rheumatoid arthritis;

• monoarthritis or asymmetrical oligoarthritis;

• spondyloarthritis mimicking ankylosing spondylitis;

• arthritis mutilans - a severe form of arthritis with marked deformity and joint destruction.

In contrast, Figure 63.2 is a characteristic plain radiograph of both hands in a patient

with longstanding rheumatoid arthritis. There is marked erosive change and fusion

Figure 63.2 Plain radiograph

of both hands in a patient

with longstanding rheumatoid

arthritis.

168

related to the carpal bones bilaterally with erosive changes also seen related to the distal

radius and ulna. Bone density is generally reduced and there is bony ankylosis of the

carpometacarpal joints. The PIPJs and DIPJs are preserved throughout.

Rheumatoid arthritis is an immunologically mediated multisystem collagen vascular dis-

ease of unknown aetiology. Treatment in the acute setting of joint involvement is similar

to that of psoriasis, but long-term treatment is complicated, often involving a delicate

balance of disease modifying drugs (DMARDs) requiring regular clinical follow-up and

blood tests. Being a multisystem disorder, rheumatoid arthritis can affect the patient in

many ways outside of joint involvement. These include:

• systemic illness - fever, malaise and weight loss;

• vasculitis - predominantly affecting small vessels, the disease can mimic polyarteritis

nodosa causing peripheral neuropathy;

• skin nodules - firm and tender skin nodules occur along tendon sheaths;

• respiratory disorders - lung nodularity with cavitation can be seen, with concomitant

pulmonary fibrosis and pleural effusion;

• cardiovascular disorders - pericarditis, pericardial effusion and myositis are recog-

nized;

• Felty’s syndrome - massive splenomegaly, often with neutropenia.

KEY POINTS

• Joint disease can precede the cutaneous manifestations of psoriasis by several years.

• Classically, psoriasis is associated with a symmetrical distal polyarthropathy of the

interphalangeal joints.

• Rheumatoid arthritis predominantly affects the distal radius and proximal joints of the

hand bilaterally.

References

1. Chapman, S. and Nakielny, R. Aids to Radiological Differential Diagnosis, 4th edn. Philadelphia:

W.B. Saunders.

2. Jacobson, J.A., Girish, G., Jiang, Y. and Resnick, D. (2008) Radiographic evaluation of arthritis:

inflammatory conditions. Radiology 248: 378-89.

169

CASE 64: TEACHING SPORT CAN BE A HEADACHE AT TIMES

History

A 38-year-old sports teacher was brought to the accident and emergency department by

ambulance. He had been found unconscious in his office by another member of staff at

the end of the afternoon. There was no sign of assault and the accompanying member

of staff remembers seeing the sports teacher at lunch where they laughed together at

something that had occurred that morning.

The sports teacher had taken his first class to the cricket nets for catching and batting

practice. During the session a batsman had driven the ball hard, accidentally hitting the

teacher on the left side of the head. Pupils near by heard a ‘crack’ but the sports teacher

did not lose consciousness and carried on with the lesson. He did report at lunchtime

feeling a little drowsy but had only administrative duties in the afternoon. On her way

home, another teacher checked on the sports teacher to find him unrousable in his office

and she raised the alarm.

Examination

Ambulance paramedics urgently brought the sports teacher to the accident and emer-

gency department. Glasgow Coma Scale score (GCS) on arrival was 7 (motor 4, eyes 2,

speech 1). He had been intubated in the resuscitation room to protect his airway, and

a cranial computed tomography (CT) scan was performed before admission to intensive

care (Figure 64.1).

Figure 64.1 Axial cranial CT scan.

Questions

• What are the CT scan findings?

• What is the diagnosis?

171

ANSWER 64

Figure 64.1 shows a single slice of a cranial CT scan taken at the level of the caudate heads.

There is asymmetry demonstrated with an area of increased density on the left side lying

underneath the left temporal bone. This abnormality is more dense than adjacent brain paren-

chyma, but less dense than the skull bones in keeping with acute blood. It has a biconvex

elliptical shape and is homogeneous in appearance. This collection of blood exerts mass effect

on adjacent brain parenchyma with total effacement of the adjacent lateral ventricle and loss

of normal left cerebral sulci. There is midline shift to the right of approximately 3 mm. The

quadrageminal cistern is effaced but the right lateral ventricle remains of expected size.

The same image rewindowed to emphasize bony pathology (Figure 64.2) demonstrates a ver-

tical fracture of the left temporal bone (arrow). There is some subcutaneous soft tissue thick-

ening at this site, which corresponds to the site of impact of the cricket ball. This represents

an acute extradural haemorrhage with mass effect compressing the brain within the skull.

Extradural haemorrhage is defined as

a collection of blood within the space

between the inner table of the skull and the

dura mater of the meninges. Blood collects

in the extradural space running along the

inside of the skull. It is strongly associ-

ated with direct head trauma and skull

fracture, with bony fragments lacerating

the meningeal vessels (commonly middle

meningeal). Depending on whether the lac-

erated vessels are arteries or veins, the rate

of haematoma expansion dictates whether

the patient presents hours or days after the

incident. Common symptoms are of gradu-

ally increasing drowsiness, which can

progress to coma as the haematoma has

focal mass effect compressing the brain

Figure 64.2 CT scan rewindowed to

within the tight skull. Some patients can

emphasize bony pathology.

demonstrate a third nerve palsy or hemi-

paresis as a sign of cerebral herniation.

An unenhanced cranial CT usually demonstrates an acute hyperdense collection of blood,

but if a few days old, can have varied attenuation appearances. It is differentiated from other

extra-axial collections by its shape. The expanding haematoma will have a biconvex ellipti-

cal shape as tracking blood is limited by the tethered cranial sutures. There may be a degree

of mass effect, and image review with bone windows has a high sensitivity for resolving

the underlying skull fracture. All patients will require urgent neurosurgical discussion and

neurologically compromised patients will require urgent decompression and evacuation.

KEY POINTS

• In an extradural haemorrhage, blood collects between the inner table of the skull and

the dura mater.

• It classically presents with reduced conscious level several hours after a traumatic incident.

• A characteristic concave elliptical haematoma is seen on CT with tracking blood

limited by cranial sutures.

172

CASE 65: A CHESTY INFANT

History

A 3-month-old boy was referred to the paediatric department by his general practitioner

(GP) with respiratory problems. He has had a cough and runny nose for 2 days and has

become progressively more chesty. He now has problems feeding, at least one episode of

vomiting that may be cough related and dry nappies. Older siblings in the family also

have coryzal symptoms. The patient was born 2 weeks prematurely with no significant

neonatal problems. The mother is on treatment for asthma and there is no other signifi-

cant medical or family history.

Examination

The initial examination showed a febrile infant with copious nasal secretions, conjunc-

tivitis and noisy breathing (grunting and wheezing). There is tachypnoea (58 breaths per

minute) with intercostal and subcostal retraction. On listening to the chest there are fine

crackles and wheeze throughout. The rest of the examination is normal.

Over the next 24 hours, the patient did not improve on standard treatment and continu-

ous positive airways pressure (CPAP) and eventually required intubation. At this point a

chest radiograph (Figure 65.1) was done to check the lungs and position of the tube (an

earlier radiograph had been unremarkable).

Six hours later, problems with ventilation developed and a further radiograph was done

(Figure 65.2).

Figure 65.1 Anterior-posterior (AP)

Figure 65.2 Later radiograph.

radiograph.

Questions

• What differentials are you considering?

• What does the first radiograph show?

• What complication has developed in the second radiograph and why?

173

ANSWER 65

Given the age and presentation, the most likely diagnosis is bronchiolitis although pneu-

monia and aspiration should also be considered. Undiagnosed congenital cardiac or lung

disease and foreign body may need to be ruled out.

The first radiograph (Figure 65.1) shows hyperinflation with flattened diaphragm. The

lung volumes are large due to air trapping rather than fortuitous timing of the radio-

graph. Coarsened lung markings that reflect patchy airspace and interstitial infiltrates are

seen. There is also some thickening of the perihilar bronchial walls (cuffing). No focal

consolidation, cardiac abnormality or foreign body is seen. The appearance is consistent

with severe bronchiolitis, although similar appearances are also seen in atypical pneu-

monia and aspiration. The tip of the endotracheal (ET) tube is well above the carina and

the tip of the nasogastric (NG) tube is below the diaphragm.

The second radiograph (Figure 65.2) shows a low ET tube in the right main bronchus result-

ing in left lung occlusion and collapse. Some compensatory hyperexpansion of the right lung

across the midline is seen. The problem is remedied by withdrawing the tube tip (ideally to

the level of the clavicles). Remember to comment on tubes and complications on every image.

The most common complication is bacte-

rial coinfection. This was suspected in this

patient’s case and shown on a subsequent

radiograph (Figure 65.3) that also showed

re-expansion of the left lung.

Bronchiolitis is usually diagnosed clini-

cally and a chest radiograph is only needed

if the course of the illness is atypical or

to rule out other causes or complications.

The small airways become infected, result-

ing in narrowing and obstruction. The

most common cause is the respiratory

syncytial virus

(RSV) and occasionally

adenovirus and parainfluenza viruses. This

may be confirmed by a nasopharyngeal

aspirate. The illness can usually be man-

Figure 65.3 Follow-up radiograph.

aged at home, but 2-3 per cent of cases

require admission to hospital of which

3-7 per cent require ventilation. Children

with underlying cardiopulmonary disease, infants with a history of gestational age less

than 34 weeks, infants younger than 6 weeks, and infants with congenital or acquired

immunodeficiency are at high risk for severe RSV infection.

KEY POINTS

• Bronchiolitis is largely diagnosed and managed without imaging.

• A chest radiograph is helpful to check for other causes and complications.

• The radiograph appearance of bronchiolitis is non-specific and may consist of

hyperexpanded lungs only, although patchy infiltrates may also be seen.

174

CASE 66: DIFFICULTY IN SWALLOWING

History

A 47-year-old mother has been referred for a barium swallow study by her general prac-

titioner (GP). She complains of increasing discomfort when eating and finds that food

sometimes gets stuck in her throat. This is more often the case when eating meat or bread,

and she finds that if she does not chew her food carefully, then each mouthful needs to

be washed down with a glass of water. She has recently taken to eating soup for most

meals, and does not find this too much of a problem. These symptoms have been getting

very gradually worse over the past 5 months, and despite her change in diet she denies

any significant weight loss.

There is no relevant past medical history, but her GP has recently prescribed iron tablets

following a blood test for feelings of increasing lethargy. She attributes this to her heavy

periods. She is a non-smoker and only drinks socially.

Examination

Her barium swallow study results are shown in Figure 66.1.

Figure 66.1 Barium swallow image.

Questions

• What does this view from the barium swallow show?

• What is the likely diagnosis?

175

ANSWER 66

For a barium swallow study, the patient is positioned between a fluoroscopy machine

containing an X-ray tube and an image intensifier. This provides a real-time image that

can be collimated to emphasize organs of the patient’s neck and chest. The patient is

asked to drink a contrast agent (e.g. barium) and hold it in the mouth. In coordination

with the radiologist, asking the patient to swallow on command allows for good opaci-

fication of the oesophagus and direct real-time observation of the passage the contrast

takes. Although many fluoroscopy studies are rarely used these days (e.g. barium ene-

mas), swallow studies using barium or iodinated contrast medium are the ‘workhorse’ of

foregut imaging. As a relatively non-invasive technique, it allows for accurate visualiza-

tion of the oesophageal diameter and mucosa, and is often used to confirm the presence

of persistent oesophageal leaks post-operatively.

This single lateral image is centred on the hypopharynx and upper oesophagus. Contrast

passes freely from the mouth to the mid-oesophagus with no evidence of hold-up or

obstruction. There is no evidence of aspiration. Within the proximal oesophagus at the

level of C5, there is an anterior ‘shelf-like’ filling defect seen. This arises at right angles

to the anterior oesophageal wall and appears to encroach into the oesophageal canal by

approximately one-third. There is no transition delay of contrast, and no evidence of

prestenotic dilatation or oesophageal diverticulosis. These features are in keeping with

an oesophageal web.

Oesophageal webs are thin membranes of normal oesophageal squamous tissue that grow

out from the anterior mucosal wall. Measuring approximately 1-2 mm in thickness, they

can cause complete or incomplete circumferential narrowing of the oesophageal lumen

and are most commonly seen in middle-aged white women. Symptoms are dependent on

the degree of obstruction, with patients complaining of dysphagia for solids rather than

liquids. Often found incidentally when patients present with feelings of globus or suffer-

ing food bolus impaction, symptoms can also include pain (odynophagia).

The aetiology of oesophageal webs is uncertain but can be both congenital, or more

commonly, acquired. They are associated with chronic inflammatory conditions of the

oesophagus including epidermolysis bullosa, pemphigus and bullous pemphigoid, and

are also seen in coeliac and graft-versus-host disease. There is a strong association with

Plummer-Vinson syndrome (PVS), in which patients experience concomitant glossitis,

angular stomatitis and iron-deficiency anaemia. Image findings should always be cor-

related with a full blood count to exclude this.

Treatment of oesophageal webs is routinely performed with balloon dilatation, and is

often a common byproduct of upper gastrointestinal endoscopy by bougienage. There is

an increased association with oesophageal cancer, and recurrence of symptoms should

be investigated early.

KEY POINTS

• A barium swallow investigation is recommended for assessment of dysphagia.

• Oesophageal webs are thin membranes of normal oesophageal squamous tissue that

grow out from the anterior mucosal wall.

• There is a strong correlation between oesophageal webs and other chronic

inflammatory conditions.

176

CASE 67: PREGNANT WOMAN WITH VOMITING

History

A 24-year-old pregnant woman with hyperemesis presents to the accident and emergency

department with chest pain and swelling around the neck after 3 days of worsening

vomiting. She is dehydrated and breathless. She is in the 10th week of a confirmed intra-

uterine twin pregnancy and has already attended the early pregnancy unit for treatment

for vomiting. There has been no per vaginal (PV) bleeding or abnormal discharge. None of

her close contacts have similar symptoms. Her medical history is otherwise unremarkable.

Examination

She appears dehydrated and mildly agitated but otherwise fit. Swelling over the lower

neck and upper chest is noted that on palpation causes crepitus. She has mild tachycardia

but no pyrexia. More crepitus is heard over the lungs. The heart sounds are normal. The

abdomen is soft and mildly diffusely tender.

You arrange a chest radiograph (Figure 67.1) and blood tests.

Figure 67.1 Posterior-anterior (PA) chest radiograph.

Questions

• What does the X-ray show?

• What imaging would you do next?

• What about the pregnancy?

177

ANSWER 67

The chest radiograph shows free gas within the upper mediastinum (i.e. a pneumome-

diastinum outlining the aorta and the trachea). There is also subcutaneous free gas (i.e.

surgical emphysema), extending from the neck down over the upper thorax. No pneu-

mothorax is seen. The lungs and heart appear normal.

Pneumomediastinum can be difficult to see on chest X-rays and is often missed if small.

The characteristic appearances are streaky lucencies in the mediastinum, gas outlin-

ing structures such as vessels, pulmonary ligament and producing lucency between the

hemidiaphragms. There may be associated pneumothoraces, pleural effusions, pneumo-

pericardium or subcutaneous emphysema.

In terms of causes, it is useful to consider where the gas has come from. If it is intra-

thoracic, it could be from:

• oesophagus perforation secondary to foreign body, tumour or persistent vomiting

(Boerhaave’s syndrome);

• trachea or major bronchi - usually the result of blunt chest trauma, pneumothorax or

tumours;

• lungs - due to alveolar rupture secondary to asthma in children, lung disease, ventila-

tion or inhaled recreational drugs;

• pleural space - pneumothorax;

• iatrogenic causes - surgery, endoscopy or positive pressure ventilation;

• spontaneous - a cause is not found, typically in older patients.

If it is extrathoracic, it could be:

• head and neck - trauma, tumour, surgery;

• subdiaphragmatic - due to perforation of a viscus with gas tracking superiorly and

through diaphragmatic openings.

Computed tomography (CT) is usually done if there is uncertainty about the radiograph

and to see the extent of free gas (Figure 67.2).

(a)

(b)

Figure 67.2 (a) Axial CT of the mediastinum showing mediastinal gas outlining the vessels and

trachea and in the subcutaneous tissues (arrows); (b) enlarged view of the mediastinum.

178

If there is suspicion of oesophageal rupture, a water-soluble contrast swallow test should

be done as there is a high risk for mediastinitis which has a poor prognosis (Figure 67.3).

(a)

(b)

Figure 67.3 (a) Lateral and (b) water-soluble contrast swallow. Adjacent outline of the tracheal

wall is seen due to interposed gas (arrow).

In Boerhaave’s syndrome, where there is oesophageal rupture secondary to vomiting,

the point of injury is typically in the left posterolateral wall a few centimetres above the

gastro-oesophageal junction, and the largest amount of gas may be in the left side of the

mediastinum. Neither of these signs is seen in Figure 67.3.

Rules governing licensing of radiology departments, which in the United Kingdom go

under the name IRMER (Ionising Radiation (Medical Exposure) Regulations 2000), require

a physician to justify the investigation, a technical member of the department to perform

the investigation and a qualified person to review and report the outcome. In addition

is the principle of the ALARP (‘as low as reasonably possible’) dose. In routine practice,

people tend to think most about this when performing X-ray investigations on children

or pregnant women. The reason is that certain types of tissue, typically rapidly growing

or metabolically active tissue, is the most radiosensitive. It is worth remembering that

some adult tissue remains more radiosensitive, in particular breast, gonads and thyroid.

The process of calculating radiation doses and including tissue sensitivities to produce

an exposure that can be used in calculating risks is complicated and is often not required

in such detail because the clinical risk associated with an uncertain diagnosis may be

much higher (e.g. in pulmonary embolism). A few numbers are helpful to get a feel for

comparative doses. Annual background is about 3 mSv, chest X-ray 0.02 mSv, abdomen

0.7 mSv, head CT 2 mSv, chest CT 8 mSv, abdominal/pelvis CT 10 mSv.

Justification for an investigation usually rests on the clinical risk of complications of a

missed diagnosis, which are typically much larger than the long-term risk of X-ray expo-

sure. In this case the surgical risk of mediastinitis and miscarriage justifies the exposure.

The ALARP principle may have been used in deciding to do the contrast swallow first as

a CT may not have been necessary if a leak had been demonstrated.

179

CASE 68: INFANT WITH A HEAD INJURY

History

A 4-month-old boy is brought into the paediatric accident and emergency department by

his parents with a head injury. The mother gives a history of the child falling from the

changing table earlier in the day and explains the delay in coming to hospital on diffi-

culties getting transport. The child otherwise has an unremarkable medical and neonatal

history.

Examination

The child is listless but with normal observations. He responds to voice by eye open-

ing but appears to move very little. He is probably a little under weight. There is a hard

irregularity in the left parietal scalp but no laceration. The fontanelles are not bulging.

There are no focal neurological signs. There appears to be some bruising over the left side

of the chest and a swollen left finger.

You are suspicious about the extent of the injuries and about the behaviour of the father

who appears to be keen to downplay the incident and leave. You discuss your concerns

with the registrar who admits the patient, arranges skull and chest radiographs (Figure

68.1 and 68.2) and contacts the on-call social services to see if the child is on the at-risk

(a)

(b)

Figure 68.1 Skull X-ray and subsequent computed tomography (CT) scan (bone window) of the

head.

181

ANSWER 68

The skull imaging shows a complex fracture of the left parietal bone extending from

the vertex inferiorly with some displacement of the fractured fragments. Not shown but

also apparent on the CT is a small subdural haemorrhage below the fracture. No signs

of raised intracranial pressure such as bulging fontanelles and compressed cerebrospinal

fluid (CSF) spaces are seen and the brain parenchyma and ventricles appear normal. The

patient and images are reviewed by the neurosurgical centre.

On the chest radiograph, three posterior left rib fractures are seen overlying the heart

shadow with associated callus formation. The chest otherwise appears normal.

The unsaid differential so far is non-accidental injury (NAI), however, it is important to

consider the alternatives, if only to dismiss them, as the diagnosis of NAI has significant

consequences. Other differentials include accidental trauma (but current injuries are not in

proportion to the history), birth trauma (too long ago), osteogenesis imperfecta (no fam-

ily history, no osteopenia seen) and rickets (requires imaging of long bone metaphyses).

Features that make NAI more likely are multiple fractures of varying ages, fractures

inconsistent with age or history or in unusual positions, posterior (rather than lateral) rib

fractures, metaphyseal corner fractures in children that have not started crawling/walking

and skull fractures that are complex, multiple, cross-sutures or not in the parietal bone.

Once a diagnosis of NAI has been considered as possible, the child is admitted for treat-

ment and retained on the ward. The findings and management are reviewed by the most

senior paediatrician and social care services are immediately involved. In terms of fur-

ther imaging, a skeletal survey is done to systematically document all and possible age

of bony injuries. If the CT is abnormal or there are neurological symptoms or ongoing

concern, brain magnetic resonance imaging (MRI) is done that may show subdural hae-

matomas of varying ages or cortical contusions or shearing injuries from shaking injury.

Delayed imaging may be helpful to show injuries acute at the time of presentation and

not easily seen (Figure 68.3).

(a)

(b)

Figure 68.3 (a) Acute and (b) delayed images of the right hand showing a fracture of the second

finger metacarpal (see arrows) with a step in image a) and sclerosis and periosteal reaction in b).

184

CASE 69: ABDOMINAL DISTENSION IN A WOMAN WITH

OVARIAN CANCER

History

A 65-year-old woman presents to the accident and emergency department with vomiting.

She is known to have metastatic ovarian carcinoma with a large primary tumour that is

invading surrounding structures. There are lung and liver metastases. She has recently

completed a course of chemotherapy. She complains of a long history of variable bowel

habit and has not opened her bowels for the last 2 days.

Examination

She looks thin and in discomfort. There is mild dehydration, no fever and observations

are normal. She has a distended abdomen that is soft but generally tender. There are

hyperactive bowel sounds on auscultation. Her chest is clear and heart sounds are normal.

You arrange an abdominal radiograph (Figure 69.1), review the staging computed tomo-

graphy (CT) scan of the pelvis from a few months previously that describes metastatic

masses and organize a water-soluble contrast enema (Figure 69.2).

Figure 69.1 Abdominal radiograph.

Figure 69.2 Water-soluble contrast enema.

Oblique projection of the sigmoid colon.

Questions

• What does the abdominal radiograph show?

• What does the enema show?

• Where does the problem lie?

187

ANSWER 69

The large bowel is investigated by introducing gas or contrast rectally, known as an

enema. Barium enemas and CT colonograms require thorough bowel preparation and

a bowel relaxant such as buscopan is given. In a barium enema, barium contrast is

introduced into the bowel through a rectal tube and then mostly removed after coating

the large bowel round to the caecum. Gas is then introduced to distend the bowel and

radiographs are taken in several planes to view the entire bowel wall. In a CT colono-

gram, gas only is introduced to distend the bowel. Supine and prone scans are made with

intravenous contrast.

A water-soluble contrast enema is typically used in acute situations where there is risk

of perforation or likelihood of surgery, and does not require bowel preparation. Leakage

of barium into the abdominal cavity runs a high risk of barium peritonitis, although in

relatively healthy patients the risk is less than 1 in 3000.

The abdominal radiograph (Figure 69.1) shows gas within dilated bowel that demon-

strates a haustral pattern (fold involving only part of the bowel wall) characteristic of

large bowel. The position is typical of the caecum and transverse colon with only a small

amount of gas in the descending and sigmoid colon. No gas is seen in the small bowel,

suggesting the terminal ileal valve is patent. The dilated bowel pattern suggests there is

an obstruction at the splenic flexure level.

In the water-soluble contrast enema (Figure 69.2), contrast was seen to flow through the

rectum, and into the sigmoid colon. Contrast passed no further than the mid-sigmoid

colon where a stricture was seen. The imaging suggests two strictures postioned in the

descending and mid-sigmoid colon.

The history and staging CT indicate that there is metastatic ovarian disease. Ovarian

carcinoma is the second most common gynaecological malignancy and fifth leading

cause of cancer deaths in women. Risk factors include nulliparity, early menarche, late

menopause and positive family history of ovarian, breast and early colorectal cancer.

It is often discovered late as abdominal symptoms of pain and distension, bowel habit

change, urinary frequency are often intermittent, non-specific and dismissed as common

abdominal twinges. The tumour spreads by direct extension, intraperitoneal implanta-

tion (often with ascites to produce omental deposits or ‘omental cake’) and lymphatic

and haematogenous spread, commonly to liver and lung. In this patient, there is bowel

obstruction remote from the tumour that invades the sigmoid colon and this may reflect

intraperitoneal implantation.

There are two aspects to this patient’s treatment. One is to relieve the immediate problem

of obstruction and the other is treating the underlying disease. With widespread metas-

tases the underlying disease is treated with chemo- and radiotherapy. The obstruction is

treated by palliative surgery to create a colostomy or stent insertion.

Increasingly stents are being used for palliative treatment of strictures using either fluor-

oscopy (movable X-ray camera) or endoscopy to pass a wire through the stricture and

then fluoroscopy to insert the stent.

188

CASE 70: WOMAN WITH A BREAST LUMP

History

A 48-year-old woman attends her general practitioner (GP) having noticed a lump in her

left breast while showering. The lump was non-tender and there had been no associated

discharge. She took no medication. She had never taken the oral contraceptive pill and

although recently post-menopausal, she had never taken hormone replacement therapy.

There was no family history of breast cancer. She was otherwise fit and well with no

previous medical or surgical history.

Examination

On examination there is a firm mass laterally and superiorly (in the upper outer quad-

rant). There are no overlying skin changes, but the mass felt firm and moves when tens-

ing the pectoral muscles and asking the patient to raise her hands above her head. There

is also evidence of palpable left axillary lymph nodes. She is referred to the local breast

service symptomatic clinic. On arrival she has a standard set of mammograms taken

(Figures 70.1 and 70.2).

Figure 70.1 Standard cranial-caudal mammograms.

190

ANSWER 70

The cranial-caudal (CC) and medio-lateral-oblique (MLO) views shown in Figures 70.1b and

70.2b, respectively, demonstrate a large irregular, spiculate tumour containing microcalcifica-

tions. The lesion is located lateral (see CC view) and slightly superior (see MLO view) to the nip-

ple in approximately the 2 o’clock position in the left breast. This is the typical appearance of

a malignant breast carcinoma. For comparison the corresponding mammograms of the normal

right breast are included in Figures 70.1a and 70.2a. The mass is causing parenchymal distor-

tion and extends posteriorly, hence explaining some fixation seen on clinical examination.

Mammography can be performed both in the context of screening (in the asymptomatic

woman) or diagnosis in the symptomatic patient. Until recently, women in the United

Kingdom were invited to attend breast screening from age 50 with a 3-year cycle and

continued to age 70. This has now been extended from 47 to 73 with self or GP referral

for older women. In younger, typically pre-menopausal women the breast tissue is denser,

making mammography less sensitive as a screening tool.

If an abnormality is found on screening it is graded, which determines the type of follow-

up. Suspicious lesions are referred to a breast clinic. The standard breast mammogram

views are bilateral CC and MLO views, which are obtained with the breast compressed, as

seen in Figures 70.1 and 70.2.

Mammography is a form of low-dose radiograph used to create detailed images of the

breast and can demonstrate microcalcifications smaller than 100 μm. It may reveal a

lesion before it is palpable by examination, hence its use in screening. Mammographic

features suggestive of malignancy include microcalcifications, soft tissue mass, asymme-

try or architectural distortion, all of which are demonstrated in Figure 70.1b.

In the breast clinic the patient undergoes a triple assessment of clinical review, mammo-

graphy and ultrasound. The ultrasound shown in Figure 70.3 confirms a 3.1 cm mass

with ill-defined margins, casting an acoustic shadow. Ultrasound is a useful adjunct to

mammography and has the benefit of not using ionizing radiation. Ultrasound can help to

determine if a breast lesion is likely to be benign (e.g. a cyst or fibroadenoma) or malignant.

Malignant lesions are characteristically poorly defined with irregular margins and posterior

acoustic shadowing, as seen in Figure 70.3. Ultrasound is also used to guide biopsy and

therapeutic procedures. In this patient’s case, the lesion was an invasive ductal carcinoma.

In certain settings magnetic resonance (MR) imaging of the breast may be indicated. This

is used for:

• further characterization of an indeterminate lesion

(despite full assessment with

examination, mammography and ultrasound);

• detection of occult breast carcinoma in a patient with carcinoma in an axillary lymph node;

• multifocal or bilateral tumours;

• invasive lobular carcinoma, which has a high incidence of multifocality;

• evaluation of suspected, extensive, high-grade intraductal carcinoma;

• detection of recurrent breast cancer.

KEY POINTS

• Breast clinic assessment typically consists of the triple assessment of clinical review,

mammography and ultrasound.

• Mammography can be used both in screening and in symptomatic presentations such

as a breast lump or discharge.

• Ultrasound can be used to characterize breast lesions and guide biopsy.

192

CASE 71: A RISING CREATININE

History

A 57-year-old man was admitted overnight complaining of haematuria and lethargy. His

symptoms have been intermittent over the last month, with occasional macroscopic blood

seen when passing urine. He complains of an increase in frequency and nocturia but no

dysuria. There is no history to suggest any stigmata of infection.

He has no relevant past medical history and lives at home with his wife and two children.

As an ex-smoker he has a tobacco history of 20 pack-years with only occasional alcohol

usage.

Examination

Examination reveals that he is afebrile and in no obvious discomfort. Cardiovascular and

respiratory examinations are normal, but on abdominal examination there is fullness at

both renal angles and mild discomfort on deep palpation.

Blood results reveal a creatinine of 515 μmol/L with normal urea and potassium. A

routine blood result from 3 months previously recorded his creatinine as 72 μmol/L. His

inflammatory markers are not elevated and a blood gas does not demonstrate any acido-

sis. Ultrasound images were taken (Figures 71.1 and 71.2).

Figure 71.1 Ultrasound of left kidney.

Figure 71.2 Ultrasound of bladder.

Questions

• What does the ultrasound show?

• What options are available to resolve the situation?

193

ANSWER 71

These are two static ultrasound images of the left kidney and the bladder. The left kidney

image is acquired in a longitudinal orientation and demonstrates normal echogenicity

and shape with preserved corticomedullary differentiation and cortical thickness. There

are serpiginous areas of anechoic echogenicity associated with the renal medulla with

cortical extension in keeping with moderate pelivocalyceal dilatation

(Figure

71.3).

Although not accurately demonstrated on this image, there is the suggestion of proximal

ureteric dilatation distal to the pelvico-ureteric junction (PUJ). Imaging of the right kid-

ney revealed identical appearances.

Renal cortex

Calyceal separation

Renal medulla

Figure 71.3 Annotated ultrasound of left kidney.

The second image (Figure 71.2) is acquired in a transverse orientation within the pelvis

and demonstrates an adequately distended bladder with an area of irregular echogenicity

seen posteriorly at the expected level of the bladder trigone. This mass lesion measures

approximately 4.3 × 2.9 cm contiguous with the bladder wall. The vesico-ureteric junc-

tion (VUJ) and distal ureters are not demonstrated on this image. The features are likely

to represent a transitional cell carcinoma (TCC) of the bladder with obstruction of both

the left and right kidneys. A staging computed tomography (CT) examination of the

chest, abdomen and bladder is recommended to characterize this further, with referral to

a urologist for continued management.

The CT scan confirmed a surgically resectable TCC with bilateral renal obstruction and no

evidence of local or distant spread. The patient ultimately requires a definitive surgical

procedure to remove the cancer, but at present, the ureteric obstruction and deterioration

in renal function makes the patient biochemically unstable. Surgery carries significant

risk, and in a non-life threatening situation, the patient should be physically and bio-

chemically optimized to encourage a safe transition through the operation, reduce the

risk of intra-operative mortality and improve post-operative recovery. This patient is

currently a poor candidate for general anaesthesia, and as a bridge to surgery there are

two options available:

194

• Cystoscopy and retrograde ureteric stent insertion: Trained urologists can pass

a camera through the patient’s urethra and visualize the bladder TCC directly. Not

only does this allow for biopsy and tissue confirmation of the TCC, but if the VUJ is

adequately visualized, a guidewire can be passed into the ureter and a ‘double-J’ stent

inserted to relieve the VUJ obstruction. Cystoscopy can be performed under conscious

sedation but general anaesthesia is preferred. In this situation, it was felt that the

tumour mass would make VUJ cannulation very difficult, making this option inappro-

priate.

• Nephrostomy and antegrade ureteric stent insertion: This minimally invasive pro-

cedure is performed by a trained interventional radiologist and can be performed

under local anaesthesia only, although light sedation is sometimes required. The

patient lies on a fluoroscopy table in the prone position, and a micropuncture needle

is passed percutaneously under direct ultrasound imaging into a dilated lower pole

calyx. Ideally this should transgress Brodel’s bloodless line, an avascular area between

the anterior and posterior renal segments to reduce the risk of renal haemorrhage.

Instilling contrast into the collecting system under fluoroscopy can confirm satisfac-

tory positioning (Figure 71.4).

Adopting the Seldinger technique, a guidewire can then be manipulated into the proxi-

mal ureter over which a sheath is passed to stabilize the position. A hydrophilic wire and

catheter combination is then used to transgress the VUJ and obstructing lesion for safe

passage of a stiff guidewire from the renal pelvis into the bladder. This allows careful

manipulation of an appropriately sized renal stent to be passed over the wire so that one

end lies within the bladder, and the other lies more proximally within the renal pelvis.

This acts as a conduit through which urine can drain for renal decompression (Figure

71.5).

Figure 71.4 Contrast fluoroscopy image

Figure 71.5 Fluoroscopy study

confirming position of lower pole colyx.

positioning ureteric stent.

Stent positioning requires a high level of accuracy and it may also become obstructed

both by tumour overgrowth and stent migration. As a precautionary measure, an addi-

tional pigtail catheter is often left within the renal pelvis, running along the line of the

original percutaneous puncture to act as a urinary diversion both for initial decompres-

sion and in case of stent failure. This is termed a covering nephrostomy and remains in

position for the short term (Figure 71.6).

195

CASE 72: NECK PAIN AFTER FALLING

History

A 21-year-old woman is brought to the accident and emergency department with head

and neck trauma after falling from a horse. She is immobilized on a board with a hard

neck collar and complains of diffuse neck pain and mild intermittent tingling in the arms

and legs. There is no history of loss of consciousness, no evidence of head injury (she had

a riding helmet on) and no complaint of injury elsewhere. There is no significant past

medical history although the patient has had intermittent neck pain in the past that has

not been investigated.

Examination

Routine observations are stable and she is maintaining her airway, breathing and circula-

tion. You perform a primary survey which reveals diffuse tenderness in the mid cervical

spine. There is abnormal sensation and hyperreflexia in lower and upper limbs. The chest,

abdomen and pelvis are normal. No limb fractures or dislocations are suspected. You

arrange trauma series radiographs of the neck (Figure 72.1).

(a)

(b)

Figure 72.1 (a) Anterior-posterior (AP) and (b) lateral cervical spine views from the trauma

series (normal AP peg view not shown). There is overlying artefact as the images are obtained

with immobilization blocks.

Questions

• Which lines do you review on cervical spine radiographs?

• Is there an abnormality on the radiograph?

• Do you have a differential diagnosis?

• What would you do next?

197

ANSWER 72

A trauma series of cervical spine radiographs includes a peg view of the dens through

the open mouth and various other views to ensure the C7/T1 junction is seen. If clear

views are not obtained or an acute abnormality is noted then a computed tomography

(CT) scan is the next step.

When assessing cervical spine radiographs, there are a number of lines that should be viewed

to help pick up abnormalities. On the lateral projection, the anterior and posterior vertebral

edges describe lines. The line through the junction of the lamina and the anterior edge of

the spinous processes (spinolaminar line) and the curve through the posterior tips of the

spinous processes should be reviewed. These lines should all be smooth and continuous with

no steps, although the natural curvature of the neck may be altered due to pain or immobi-

lization. Any small fragments of bone should be considered for fractures although may be

ossification centres in younger patients or degenerative changes in older patients. On the AP

view look at the lines through and spacing between the spinous processes and the pedicles.

The radiographs show a gap in the spinolaminar line at C5 with absence of a normal

spinous process and an expanded appearance of both pedicles and lamina, best seen on

the AP projection. The anterior and posterior vertebral lines appear normal. No fracture

is identified, however, the appearance suggests a chronic expansile bone lesion involving

the pedicles and spinous process of C5 that may be narrowing the spinal canal. No sig-

nificant soft tissue swelling or periosteal reaction is seen to suggest an aggressive process.

In the absence of a fracture, the patient’s acute symptoms are likely to be due to cord

trauma secondary to spinal stenosis (narrowing) that may be due to the underlying bone

lesion or a new haematoma. Spinal stenosis can be congenital or acquired and most often

affects the cervical or lumbar spine. Degenerative change or metastatic bone lesions are

common causes in patients over 50. Congenital or acquired primary bone lesions as well

as trauma are more common in younger patients.

A CT is required to characterize the bone changes and ensure there is no traumatic injury

(Figure 72.2).

(a)

(b)

Figure 72.2 (a) Coronal and (b) sagittal images of the patient’s cervical spine showing the

expansile lesion in the posterior elements of the C5 vertebra. No fracture is seen.

198

Given the patient’s neurology, an emergency magnetic resonance (MR) scan is required

to examine the spinal cord, nerve roots and soft tissue associated with the bone lesion

(Figure 72.3).

(a)

(b)

Figure 72.3 Sagittal MR (a) T1- and (b) T2-weighted images of the patient’s cervical spine.

The MR shows an expansile lesion of the C5 spinous process with associated narrowing

of the spinal canal and increased T2 signal (altered water content) within the spinal canal

at this point. The high signal is most likely to be inflammatory due to trauma and cord

swelling rather than a tumour or haemorrhage.

Given the patient’s age, possible differential diagnoses for expansile lesions in the cervi-

cal spine include benign tumours from the bone such as an aneurysmal bone cyst, as

in this case, or from the spinal cord or nerve roots such as a neurofibroma. Malignant

bone tumours are less likely given the age and history but could include lymphoma.

Osteomyelitis should also be ruled out although unlikely in this case.

The patient requires urgent referral to a neurosurgical/spinal orthopaedic centre for pos-

sible removal of the lesion to decompress the cord. Steroids may help to reduce cord

swelling.

KEY POINTS

• Acute or symptomatic spinal stenosis is an emergency and one of the few situations

requiring an emergency MR to view the cord.

• Degenerative changes and disc prolapse are the most common causes of spinal

stenosis, but the differential includes tumours and haematomas.

199

CASE 73: A YOUNG MAN WITH BACK PAIN

History

This 25-year-old man presents to you in the accident and emergency department with

lower back pain that is so bad he is unable to walk. He gives a history of gradually wors-

ening back pain over the last few months. He also complains of night sweats and bowel

disturbance. He does not give a history of other medical problems and says that he is not

working currently. He smokes 15 cigarettes a day and drinks at least 30 units a week. He

takes cannabis regularly but denies use of intravenous drugs.

Examination

On examination he is thin and appears to neglect his appearance. His blood pressure,

pulse and temperature are a little elevated. His chest and heart sounds are normal. The

abdomen is soft. There is evidence of injection sites in the forearms and antecubital fos-

sae. He is extremely tender over the lower spine. Neurologically, he has reduced power

(4/5) on leg raising bilaterally.

You arrange investigations including a chest and lumbar spine radiograph (Figure 73.1)

and, on the basis of that, a magnetic resonance (MR) scan of the spine is arranged (Figure

73.2).

(a)

(b)

Figure 73.1 (a) Anterior-posterior (AP) and (b) lateral lumbar spine plain radiographs.

200

(a)

(b)

Figure 73.2 T1-weighted sagittal MR image of the lumbar spine, pre (a) and post (b) gadolinium

contrast.

Just to give a brief summary of MR, hydrogen is a ubiquitous atom present in water and

most biological molecules. In a magnetic field, the magnetic moment of the hydrogen

nucleus becomes polarized and can be switched between aligned parallel and antiparallel

with the magnetic field by radiofrequency pulses. Add in a magnetic field gradient to

change the frequency at which the protons resonate according to position and you have

the beginnings of spatial resolution and an MR image.

The protons relax from an ordered polarized state once the radiofrequency pulse has

stopped. The relaxation of polarization is measured with the T1 rate constant, and the

rate at which they become disorganized by T2. T1 and T2 are used as contrast parameters.

Fat and proteinaceous fluid have high T1 and T2 signals. Water has low T1and high T2

signal. Soft tissues are somewhere inbetween. Abnormalities often have high T2 signal.

T1 images tend to be used for anatomy, comparison with T2 images or used with gado-

linium contrast (high T1 signal).

Questions

• What do the figures demonstrate?

• Why was an MR scan ordered?

• What is the differential diagnosis.

• What would you do next and how?

• What is the appropriate treatment?

201

ANSWER 73

The plain radiograph (Figure 73.1) shows loss of disc and vertebral height at L4 and L5.

In many ways the MR images (Figure 73.2) complement the plain radiograph. Although

the bone cortex appears dark, the marrow is bright due to fat. Loss of normal fat signal in

L4 and 5 vertebral bodies results from inflammation and increased water signal. Contrast

enhancement also reflects the pathological processes centred on the disc and affecting the

bone. MR is also excellent for looking at soft tissues, particularly in this case the anterior

paravertebral soft tissue mass as well as soft tissue impinging into the spinal canal and

on to the nerve roots and the spinal cord itself.

With this patient’s history there is a risk of immune suppression and a high risk of infec-

tion and the most likely diagnosis is infective discitis. Despite his denial, the injection

marks without any other explanation makes it likely that he uses intravenous drugs. The

differential diagnosis of malignancy is quite unlikely as this tends to affect primarily the

vertebra. Osteomyelitis is also a differential if there is not disc involvement, however, in

this case it is coexistent with the discitis.

Infection in the spine is typically the result of either bloodborne spread or through an

invasive procedure. Infections can be either pyogenic or non-pyogenic. Pyogenic discitis

most commonly involves Staphylococcus aureus or gram-negative bacilli in intravenous

drug users or immunocompromised patients. Non-pyogenic discitis may be caused by

tuberculosis (TB).

In children, where there is still vascularization of the disc, the infection arises in the disc.

In adults, the infection arises in the vertebral endplate and then crosses the disc to the

next endplate. Typical changes seen on imaging include loss of disc height and increas-

ing loss of vertebral endplates with destruction and collapse. There may be formation of

adjacent soft tissue masses or collections that may, particularly in TB, spread beneath the

longitudinal ligaments to involve multiple levels.

Diagnosis typically requires identification of the organism. In some cases this may be

secondary to infection or a collection elsewhere and identified on blood or other sample

culture. Otherwise a biopsy is required to obtain some infected tissue. This is typically

done using image-guided needle biopsy to negotiate the nerve roots and position the

needle tip in the optimum position (Figure 73.3). This patient’s biopsy yielded TB.

202

ANSWER 74

On the first radiograph (Figure 74.1a) it is difficult to appreciate a bony injury, but the

second trauma view (Figure 74.1b) clearly demonstrates a fracture line passing through

the base of the thumb proximal phalynx metaphysis into the epiphyseal plate. The frac-

ture line does not, however, pass through into the epiphysis. This is the classical appear-

ance of a Salter-Harris type II fracture.

Salter-Harris fractures are fractures through a growth plate and, as a result, unique to

paediatric patients. They are common injuries found in children, occurring in approxi-

mately 15 per cent of long bone fractures. These fractures are classified according to the

involvement of the physis, metaphysis and epiphysis. This categorization of the injuries

is important because it not only affects patient treatment but may also alert the clinician

to potential longer term complications.

There are nine types of Salter-Harris fracture in total, although types I-V are the most

commonly referred to and were those described originally (the rarer types VI-IX have

been added subsequently). The radiographic findings vary according to the type of Salter-

Harris fracture.

The most common type of Salter-Harris fracture, is the type II fracture (see arrow Figure

74.2). This occurs through the physis and metaphysis, and the epiphysis is not involved

in the injury (no fracture is observed in the epiphysis).

Figure 74.2

Salter-Harris type II fractures tend to occur after age

10. The mechanism involves

shearing or avulsion with angular force. There is cartilage failure on the tension side.

Metapetaphyseal failure occurs on the compression side. There is a division between

epiphysis and metaphysis except for a flake of metaphyseal bone, which is carried with

the epiphysis. The metaphyseal fragment is sometimes called the Thurston-Holland frag-

206

ment. These fractures may cause minimal shortening, however healing is usually rapid

and Salter-Harris type II injuries rarely result in functional limitations.

With type I Salter-Harris fractures, initial radiographs may suggest separation of the

physis although this separation may not be apparent and soft tissue swelling typically

overlying the physis may provide the only clue. Follow-up radiographs within 2 weeks

after injury help establish the diagnosis. Adjacent sclerosis and/or periosteal reaction

along the epiphyseal plate supports the diagnosis of a Salter-Harris type I fracture. The

growing physis is not usually injured in type I fractures, however, and growth distur-

bance is uncommon.

The type III fracture passes through the physis and extends to split the epiphysis. The

fracture crosses the physis and extends into the articular surface of the bone. Type IV

injuries pass through the epiphysis, physis and metaphysis. As with type III fractures, the

type IV pattern is an intra-articular injury and therefore can result in chronic disability.

Type V fractures are compression/crush injuries of the epiphyseal plate, without associ-

ated epiphyseal or metaphyseal fracture. The initial plain radiographs in type V fracture

may not show a fracture line (similar to type I fractures). Soft-tissue swelling at the phy-

sis, however, is usually present. The clinical history is central to the diagnosis of type V

fractures and a typical history is that of an axial load injury. Type V injuries have a poor

functional prognosis.

KEY POINTS

• Salter-Harris fractures are fractures through a growth plate.

• Imaging findings vary according to the type of Salter-Harris fracture.

• The most common type of Salter-Harris fracture is the type II fracture which occurs

through the physis and metaphysis (the epiphysis is not involved in the injury).

• The diagnosis of type V may be particularly difficult, however is important as these

injuries have a poor functional prognosis.

• Two views are required in the evaluation of all cases of traumatic injury.

207

CASE 75: A RENAL TRACT ABNORMALITY

History

A 60-year-old man presents to his general practitioner (GP). Over the course of the last

month he has noted bright red blood in his urine. He had hoped that it would simply

go away but instead he has now developed loin discomfort, particularly on the right. He

has not felt feverish or lost any weight. He is an ex-smoker and takes antihypertensive

medication, but otherwise he has been well.

Examination

He was afebrile and his observations were all within normal limits. Upon palpation the

abdomen was soft and no mass was felt. There was tenderness in the right renal angle but

no direct pain on palpation. His white cell count was slightly elevated at 13 × 10⁹/L and

his C-reactive protein (CRP) is 20 mg/L. He also demonstrates a mild normocytic anaemia

with a haemoglobin of 10.4 g/dL. Urine dipstick reveals frank blood. He is referred for an

ultrasound scan which is reported as ‘bilateral hydronephrosis, although the bladder was

suboptimally distended therefore could not be completely evaluated.’ One longitudinal

image of the right kidney is seen in Figure 75.1. On the basis of the ultrasound scan,

further imaging with computed tomography (CT) was arranged with the local radiology

department. A coronal reconstructed image is seen in Figure 75.2.

Figure 75.1 Ultrasound image.

Question

• What do the ultrasound image in Figure

75.1 and the CT image in Figure 75.2

demonstrate?

Figure 75.2 CT scan.

209

ANSWER 75

Figure 75.1 demonstrates dilatation of the right renal pelvicalyceal system consistent with

hydronephrosis. Compare this appearance with that of a normal unobstructed kidney in

Figure 75.3.

Figure 75.3 Ultrasound of normal kidney.

Figure 75.2 shows a coronal contrast-enhanced CT image demonstrating dilatation of the

renal collecting system bilaterally.

This patient has bilateral hydronephrosis (seen on ultrasound and CT) in combination

with frank haematuria. A cystoscopy was then arranged which confirmed the presence of

a bladder lesion obstructing both ureteric orifices.

Hydronephrosis is distension and dilatation of the renal pelvis calyces, usually caused by

the obstruction of the free flow of urine from the kidney(s), and may lead to progressive

atrophy of the kidney(s). This case demonstrates only one cause of hydronephrosis.

A multitude of causes exist for hydronephrosis and hydroureter, ranging from benign

processes, such as the physiologic hydroureteronephrosis of pregnancy, to potential life-

threatening situations, such as infected hydronephrosis or pyonephrosis. Classification

can be made according to the level within the urinary tract (interruption can occur

anywhere along the urinary tract from the kidneys to the urethral meatus) and whether

the aetiology is intrinsic, extrinsic or functional. Causes at ureteric level can be intrinsic

(for example, ureteropelvic junction stricture, blood clot, retrocaval ureter), functional

(for example, gram-negative infection or neurogenic bladder) or extrinsic (for example,

retroperitoneal or pelvic malignancy or pregnancy). At the level of the bladder intrinsic

causes include carcinoma (as in this case), calculi, cystocele or diverticula; functional

causes include vesico-ureteric reflux; and extrinsic causes again include malignancy and

pelvic lipomatosis. Urethral causes may also be intrinsic, such as strictures or valves, or

extrinsic, such as prostatic pathology.

Although patients usually present with signs or symptoms, hydronephrosis can be

an incidental finding encountered during the evaluation of an unrelated process.

210

Hydronephrosis that occurs acutely with sudden onset (for example, due to a renal cal-

culus) can cause intense pain in the flank area, while a chronic occurrence that develops

gradually will present with no pain or attacks of a dull discomfort. Nausea and vomiting

may also occur. An obstruction that occurs at the urethra or bladder outlet can cause

pain and pressure resulting from distension of the bladder. Blocking the flow of urine

will commonly result in urinary tract infections which can lead to the development of

additional stones, fever, and blood or pus in the urine. If complete obstruction occurs,

kidney failure may follow.

If unrecognized or left untreated, hydronephrosis/hydroureter secondary to obstruction

can lead to hypertension, loss of renal function, and sepsis. Consequently, patients found

to have hydronephrosis or hydroureter should undergo a thorough evaluation. The spe-

cific treatment of a patient with hydronephrosis depends on the aetiology of the process,

with any signs of infection within the obstructed system warranting urgent intervention

(as infection of an obstructed system may progress rapidly to sepsis).

KEY POINTS

• The appearances of hydronephrosis on ultrasound or CT are of a dilated renal pelvis

and calyceal system.

• A multitude of causes exist, with classification made according to the level within the

urinary tract and whether the aetiology is intrinsic, extrinsic or functional.

• Treatment of hydronephrosis focuses upon the removal of the obstruction and/or

drainage of the urine that has accumulated behind the obstruction.

• Any sign of infection within an obstructed system should prompt urgent intervention.

211

ANSWER 76

Figure 76.1 is a sagittal T2-weighted MR image of the lumbar-sacral spine, which dem-

onstrates a disc prolapse at the level of L5/S1. Figure 76.2 is an axial T2-weighted MR

image through the level of the disc herniation, which demonstrates the disc effacing the

left L5 nerve root as it exits the spinal canal.

A spinal disc herniation is a medical condition affecting the spine, in which a tear in the

outer, fibrous ring (annulus fibrosus) of an intervertebral disc allows the soft, central portion

(nucleus pulposus) to bulge out. Tears are frequently posterolateral owing to the presence of

the posterior longitudinal ligament in the spinal canal. Nuclear material that is displaced into

the spinal canal is associated with an inflammatory response, and the tear in the disc ring

can result in the release of inflammatory chemical mediators which may directly cause pain,

even in the absence of nerve root compression. This is the rationale for using anti-inflam-

matory medication for pain associated with disc herniation, protrusion, bulge or disc tear.

A weakened annulus is a necessary condition for herniation to occur. Many cases involve

trivial trauma, sometimes in the presence of repetitive stress. Traumatic injury to lumbar

discs commonly occurs when lifting while bent at the waist, rather than lifting with the

legs while the back is straight.

Lumbar disc herniations occur most often between the fourth and fifth lumbar vertebral

bodies or between L5 and the S1 (as in this example). Symptoms can affect the lower

back, buttocks, thigh, anal or genital region (via the perineal nerve) and may radiate into

the foot. The sciatic nerve is the most commonly affected nerve, causing symptoms of

sciatica. The femoral nerve may also be affected.

Plain radiographs do not demonstrate disc herniation but are useful in the diagnosis of

other conditions, particularly fracture, bone metastases or infection, and should be the

primary imaging modality when trauma, malignancy or infection are suspected.

MR imaging is the modality of choice for delineating herniated nucleus pulposus and its

relationship with adjacent soft tissues. On MRI, disc prolapses appear as focal, asymmetric

protrusions of disc material beyond the confines of the annulus. Herniation of the nucleus

pulposus are usually hypo-intense, however, because disc herniations are often associated

with a radial annular tear, high signal intensity in the posterior annulus is often seen on

sagittal T2-weighted images.

On sagittal MR images the relationship of herniation of the nucleus pulposus and degen-

erated facets to exiting nerve roots within the neural foramina is well delineated. In

addition, free fragments of the disc are easily detected on MRI.

In cases of disc bulging, early MR findings include loss of the normal posterior disc

concavity. Moderate bulges appear as non-focal protrusions of disc material beyond the

borders of the vertebrae. Bulges are typically broad based, circumferential and symmetric.

A radial tear of the annulus fibrosus is considered a sign of early disc degeneration. It is

accompanied by other signs of disc degeneration, such as a bulging annulus, loss of disc

height, herniation of the nucleus pulposus and changes in the adjacent endplates.

KEY POINTS

• Herniation of the nucleus pulposus through an annular defect causes focal protrusion

of the disc material beyond the margins of the adjacent vertebral endplate.

• MR imaging is the modality of choice for demonstrating the relationship of the herniated

nucleus pulposus and degenerated facets to exiting nerve roots within the neural foramina.

214

CASE 77: A CHRONIC PRODUCTIVE COUGH

History

A 30-year-old woman is admitted to hospital with a fever and a cough. She has a history

of repeated chest infections for several years, two of which have required hospital admis-

sion. She has been coughing up yellow-green purulent sputum for two days. She has had

some streaky haemoptysis but is not worried as this has occurred on previous occasions.

Examination

Her observations were stable with a heart rate of 80 per minute and a blood pressure of

124/82. Her respiratory rate was 22 per minute, with reduced air entry bilaterally and

diffuse coarse crackles most pronounced over the lower zones posteriorly. Her blood

haematology showed a leucocytosis and raised C-reactive protein. Her biochemistry and

liver function tests were normal. Chest radiograph and computed tomography (CT) scans

were taken (Figures 77.1 and 77.2).

Figure 77.1 Chest radiograph.

Figure 77.2 Axial CT image taken at the level

of the lower lobes.

Question

• What do the chest radiograph and axial CT image demonstrate?

215

ANSWER 77

The chest radiograph (Figure 77.1) shows ring opacities (cystic changes) due to the dila-

tation of bronchi with crowding of the vascular markings and prominent parallel lines

(tram tracks) presenting thickened walls of the dilated bronchi.

On the axial CT scan through the lower lobes the bronchi are dilated and larger than the

accompanying vessels. This is abnormal and sometimes referred to as the ‘signet ring

sign’. The signet ring sign consists of a small circle of soft tissue attenuation that abuts a

ring of soft tissue attenuation surrounding a larger low attenuating circle of air. The ring

of soft tissue attenuation represents the wall of the dilated bronchus seen on an axial CT

scan, whereas the low attenuating circle of air represents air within the dilated bronchus.

The circle of soft tissue attenuation abutting the ring represents the pulmonary artery that

lies adjacent to the dilated bronchus seen in cross-section. In Figure 77.2 dilated, thick-

walled, slightly ectatic bronchi are demonstrated within both lower lobes.

Bronchiectasis is the irreversible dilatation of part of the bronchial tree. The bronchi

involved are dilated, inflamed and collapsible. This results in airflow obstruction and

impaired clearance of secretions. Bronchiectasis is associated with a wide range of disor-

ders, some inherited, such as cystic fibrosis or agammaglobulinaemia, and some acquired,

such as necrotizing bacterial infections caused by Staphylococcus or Klebsiella or early

childhood infections caused by measles or Bordetella pertussis.

Haemoptysis, as experienced by the patient in this case, is common and may occur in up

to 50 per cent of patients. Episodic haemoptysis with little sputum production or ‘dry’

bronchiectasis is a sequela of tuberculosis. When massive haemoptysis occurs, the bleed-

ing usually originates in dilated bronchial arteries, which contain blood at systemic as

opposed to pulmonary pressures.

The diagnosis of bronchiectasis is based on a clinical history of frequent viscid sputum

production and characteristic CT scan findings.

Chest radiography is usually the first imaging examination, but the findings are often

non-specific and the images may appear normal in patients with minor to moderate

disease. Abnormal radiographic findings may be non-specific and confirmation using

high-resolution CT (HRCT) scanning may be required.

Although subtle, thick-walled and dilated bronchi are present on the radiograph in Figure

77.1. Potential abnormal plain radiographic findings in bronchiectasis include: parallel

line ‘tram track’ opacities caused by thickened dilated bronchi; ring opacities or cystic

spaces as large as 2 cm in diameter resulting from cystic bronchiectasis, sometimes with

air-fluid levels; tubular opacities caused by dilated fluid-filled bronchi; increased size

and loss of definition of the pulmonary vessels in the affected areas as a result of peri-

bronchial fibrosis; crowding of pulmonary vascular markings from the associated loss of

volume, usually caused by mucous obstruction of the peripheral bronchi; oligaemia as a

result of reduction in pulmonary artery perfusion in severe disease; signs of compensa-

tory hyperinflation of the unaffected lung.

CT, in particular HRCT, scanning has become the imaging modality of choice for dem-

onstrating and defining the extent of bronchiectasis. HRCT allows evaluation of the sur-

rounding lung tissue and assessment for other lesions.

On HRCT scans in patients with bronchiectasis, the internal bronchial diameter may be

greater than that of the adjacent artery and there may be a lack of bronchial tapering. The

bronchi may be within 1 cm of costal pleura or abut the mediastinal pleura and bronchial

216

CASE 78: GENERAL FATIGUE AND WEAKNESS

History

A 65-year-old man presents to his general practitioner (GP) with breathing difficulty over

the past month, along with problems chewing, talking and walking up the stairs in his

house. Of particular concern, he had noticed his eyelids drooping and he had difficulty

maintaining a steady gaze. He noted that he has felt persistently fatigued and his symp-

toms worsened with activity and improved with rest.

Examination

He was afebrile. His pulse was 74/minute and blood pressure 126/78. The chest was clear,

breath sounds vesicular although there was reduced expansion and a respiratory rate of

22/minute.

Neurological examination demonstrated bilateral ptosis along with weakness of the arms,

legs and swallowing muscles. The jaw was slack and the voice had a nasal quality. Muscle

weakness was worsened by repetitive or sustained use of the muscles involved. Recovery

of strength was seen after a period of rest.

Full blood count and biochemistry were normal. Due to the difficulty in breathing, the

patient was referred for a chest radiograph (Figure 78.1) and computed tomography (CT)

scan (Figure 78.2).

Figure 78.1 Chest radiograph.

Figure 78.2 CT scan.

Questions

• What is the abnormality on the chest radiograph?

• Where is the lesion anatomically located?

• Does Figure 78.2 confirm your suspicion?

• What is the differential diagnosis?

219

ANSWER 78

Figure 78.1 shows a smooth, well-defined mass arising from the left side of the mediastinum.

By virtue of the fact that the margin of the descending thoracic aorta can be clearly seen,

this mass does not lie within the posterior mediastinum. Furthermore, the hilar structures

can also be seen making the middle mediastinum an unlikely location. Indeed the axial CT

scan seen in Figure 78.2 demonstrates that the mass lies within the anterior mediastinum.

Anatomically the mediastinum lies between the right and left pleura, in and near the

median sagittal plane of the chest. It extends from the sternum in front to the vertebral

column behind, and contains all the thoracic viscera except the lungs.

It may be divided into superior and inferior parts:

• The superior mediastinum lies above the upper level of the pericardium at the plane

drawn from the sternal angle to the disc of T4-T5 (angle of Louis).

• The inferior mediastinum lies below the superior margin of the pericardium and is fur-

ther subdivided into three parts: anterior - in front of the pericardium; middle - con-

taining the pericardium and its contents; posterior - behind the pericardium.

The mediastinum is surrounded by the chest wall anteriorly, the lungs laterally and

the spine posteriorly. It is continuous with the loose connective tissue of the neck, and

extends inferiorly onto the diaphragm.

The location of a mass within the mediastinum can be deduced radiologically on the plain

chest radiograph by assessing a number of radiological landmarks. In Figure 78.1 the margin

of the descending aorta and thoracic vertebrae/ribs, which are posterior mediastinal struc-

tures, can be seen crisply and clearly. This suggests that the lesion is not within the posterior

mediastinum (where the presence of a mass located in opposition to these structures would

cause a silhouette sign). The vascular structures of the hilum are also preserved. Therefore, the

mass most likely lies within the anterior compartment. This is confirmed on CT (Figure 78.2).

The anterior mediastinum contains the following structures: thymus, lymph nodes, pul-

monary artery, phrenic nerves and thyroid. The most common lesions encountered in the

anterior mediastinum arise from thyroid, thymic (thymoma) or lymph node (lymphoma)

origin. Germ cell tumours (teratoma) arise from pluripotent cells of the thymus.

This case was later proven to be a thymoma, in the context of myasthenia gravis. Indeed

as many as 30-40 per cent of patients who have a thymoma experience symptoms sug-

gestive of myasthenia gravis. The thymus is a lymphoid organ located in the anterior

mediastinum. In early life, the thymus is responsible for the development and maturation

of cell-mediated immunological functions.

The thymus gland is located behind the sternum in front of the great vessels. It reaches

its maximum weight at puberty and undergoes involution thereafter. Peak incidence of

thymoma occurs in the fourth to fifth decade of life. No sexual predilection exists.

Of patients with a thymoma, one-third to one-half are asymptomatic. Others often present

with local symptoms related to the tumour encroaching on surrounding structures. These

patients may present with cough, chest pain, superior vena cava syndrome, dysphagia and

hoarseness (if the recurrent laryngeal nerve is involved). One-third of thymoma cases are

found on radiographic examinations during a work-up for myasthenia gravis, as in this case.

KEY POINTS

• The anatomical location of a mediastinal mass may be deduced from the plain

radiograph by assessing for anatomical landmarks.

220

CASE 79: A CERVICAL SPINE INJURY FOLLOWING A HORSE-

RIDING ACCIDENT

History

A 14-year-old girl is thrown from her horse while making a jump. She landed on her head

with her neck in the hyperflexed position. She denies any loss of consciousness, although

she is taken into accident and emergency with her neck immobilized, complaining of

severe pain in her lower cervical spine. She had sustained no other obvious injury and

has no significant medical history.

Examination

She is maintaining her airway. Examination of the chest, abdomen and pelvis is unre-

markable. Neurological assessment fails to demonstrate a focal deficit. Sensation, power

and reflexes are normal in all four limbs. Per rectal examination reveals normal tone.

There is concern regarding her cervical spine injury, therefore a lateral radiograph is per-

formed (Figure 79.1). A computed tomography (CT) scan is subsequently performed with

a sagittal reformat image shown in Figure 79.2.

Figure 79.1 Lateral radiograph.

Figure 79.2 Sagittal reformat CT scan.

Questions

• What does the lateral cervical spine radiograph show?

• What does the CT scan demonstrate?

221

ANSWER 79

This 14-year-old girl has sustained a hyperflexion ‘teardrop’ fracture of C7 which is

also crushed. There is wedging of the vertebral body with retropulsion of the posterior

fragment into the spinal canal. This can be seen on both the initial lateral radiograph

Figure 79.1 and more clearly on the sagittal CT image of the cervical spine (Figure 79.2).

A flexion teardrop fracture occurs when flexion of the spine, along with vertical axial

compression, causes a fracture of the anterior-inferior aspect of the vertebral body. This

fragment is displaced anteriorly and resembles a teardrop.

For this fragment to be produced significant posterior ligamentous disruption must occur

and as the fragment displaces anteriorly, a significant degree of anterior ligamentous

disruption must take place.

This example demonstrates a flexion injury, however, cervical spine injuries are classi-

fied according to several other mechanisms of injury in addition to flexion, including

flexion-rotation, extension, extension-rotation, vertical compression, lateral flexion and

mechanisms resulting in odontoid (C2) fractures and atlanto-occipital dislocation.

The cervical spine should be seen as three distinct columns:

• Anterior column: This is composed of the anterior longitudinal ligament and the

anterior two-thirds of the vertebral bodies, the annulus fibrosus and the intervertebral

discs.

• Middle column: This is composed of

the posterior longitudinal ligament and

the posterior one-third of the vertebral

bodies, the annulus and intervertebral

discs.

• Posterior column: This contains all of

the bony elements formed by the pedi-

cles, transverse processes, articulating

facets, laminae and spinous processes.

If one column is disrupted, other columns

may provide sufficient stability to prevent

spinal cord injury. If two columns are

disrupted, the spine may move as separate

units, increasing the likelihood of spinal

cord injury.

This fracture is important to recognize

as it is an unstable type of cervical spine

fracture involving disruption of all three

spinal columns, making this an extremely

unstable fracture that frequently is associ-

ated with spinal cord injury.

The girl in this case was referred to the spi-

nal service and initially managed with the

application of traction with cervical tongs,

but later underwent a C7 corpectomy and

fusion (Figure 79.3).

Figure 79.3 Lateral radiograph post surgery

showing C7 corpectomy and fusion.

222

When interpreting lateral cervical views, first you should check the technical adequacy

of the radiograph, which must show all seven vertebral bodies and the cervicothoracic

junction. Next, look for soft tissue changes in predental and prevertebral spaces (if the

prevertebral space is widened at any level, a haematoma secondary to a fracture is likely).

At the level of C2, prevertebral space should not exceed 7 mm and at the level of C6 and

below, where the prevertebral space is widened by the presence of the oesophagus and

cricopharyngeal muscle, no more than 22 mm in adults/14 mm in children younger than

15 years.

Then check the alignment of the cervical spine by following three imaginary contour

lines:

• The first line connects the anterior margins of all the vertebrae and is referred to as

the anterior contour line. It is clearly disrupted in Figure 79.1.

• The second line should connect the posterior aspect of all vertebrae in a similar way

and is referred to as the posterior contour line. This is also disrupted in Figure 79.1.

• The third line should connect the bases of the spinous processes. This is referred to as

the spinolaminar line.

KEY POINTS

• Approximately 85-90 per cent of cervical spine injuries are evident in lateral view.

• An acceptable lateral view must show all seven vertebral bodies and the

cervicothoracic junction.

• It is important to check the alignment of cervical spine by following three imaginary

contour lines.

• Soft tissue changes in predental and prevertebral spaces should always be looked for.

223

CASE 80: ABDOMINAL PAIN AND DIARRHOEA IN A 28-YEAR-OLD

WOMAN

History

You are asked to review the abdominal radiograph of a 28-year-old woman who has

presented to the accident and emergency department with worsening abdominal pain and

diarrhoea. She is known to have a diagnosis of ulcerative colitis and, despite occasional

disease exacerbations as a teenager, she has been symptom free for 5 years.

Over the last 2 days she has been complaining of generalized aching abdominal pain. This

is associated with diarrhoea that is increasing in frequency and yesterday she opened her

bowels nine times. Overnight she was unable to control her loose motions and noticed

fresh blood with streaks of pus within the stool. She denies weight loss but gives a his-

tory of feeling very lethargic.

She attended the accident and emergency department worried about an acute attack of

ulcerative colitis and was found to be tachycardic but normotensive on examination.

Her abdomen was distended but not peritonitic, and she reported pain on deep palpa-

tion, most marked within the left upper quadrant. Her blood results suggest a degree of

renal impairment and dehydration, with a slightly elevated white cell count but normal

haemoglobin.

Examination

As part of the initial investigations an abdominal radiograph was performed (Figure 80.1).

Figure 80.1 Abdominal radiograph.

Questions

• What does the abdominal radiograph demonstrate?

• What further imaging is recommended?

• Is there a differential diagnosis for these appearances?

225

ANSWER 80

This is an anterior-posterior abdominal radiograph of an adult female. There is gross

abnormality of the large bowel with widespread dilatation most marked at the splenic

flexure, where the maximal bowel diameter measures 10.3 cm (normal large bowel

diameter <6cm). There is abnormal thickening and ‘thumbprinting’ of the colonic wall

with loss of normal haustrations due to mucosal oedema. There is no evidence of small

bowel involvement and no characteristic appearances of ‘Rigler’s sign’ (see below) to

suggest extraluminal free gas related to bowel perforation. The appearances are con-

sistent with colitis with bowel dilatation, in keeping with toxic megacolon. Urgent

surgical opinion should be sought and clinical correlation advised since perforation is

a significant risk.

A computed tomography (CT) scan of the abdomen and pelvis is recommended to char-

acterize the radiograph findings further (Figure 80.2). Ideally, this should be performed

with intravenous contrast in the portal venous phase, however, renal function derange-

ment from fluid sequestration may make this impossible. The possible need for surgery is

a relative contraindication to oral contrast enhancement.

Dilated sigmoid colon

Thickened odematous wall

Pericolic fat stranding

with hyperenhancement of

mucosal surface

Figure 80.2 Enhanced CT scan.

This single enhanced CT image acquired at a level just superior to the femoral acetabulae

demonstrates dilatation and thickening of the sigmoid colon. There is hyperenhancement

of the mucosa and muscularis propria, which outline an iso-attenuating oedematous

submucosa. There is associated pericolic fat stranding. These findings suggest acute

inflammatory change. There is no evidence of free fluid within the pelvis and no extra-

luminal free gas on this image, although the whole study should be reviewed to exclude

perforation.

Inflammation of the colon is termed ‘colitis’ and its causes are numerous:

• Infection: bacteria (E. coli, Salmonella), parasites (amoebiasis), fungi (histoplasmosis)

and viruses (HIV, CMV) can all cause pancolitis and marked wall oedema.

226

• Ischaemia: The splenic flexure/descending colon are a watershed area demarcated by

the blood supply from the superior and inferior mesenteric arteries. It is particularly

susceptible to ischaemia of any cause (e.g. atherosclerosis), and the colitic appearances

can mimic inflammatory bowel disease. The characteristic appearance of air within the

wall of the colon is termed ‘pneumatosis coli’ and is highly suggestive of ischaemic

colitis. It is usually a premorbid phenomenon (Figure 80.3).

Figure 80.3 Scan showing air within the wall

of the colon: pneumotosis coli.

• Pseudomembranous: Often caused by an overgrowth of the Clostridium difficile bac-

terium related to antibiotic usage, predisposed patients can suffer a pancolitis with

deterioration to toxic megacolon.

• Inflammatory bowel disease: Ulcerative colitis (UC) and Crohn’s disease are difficult to

differentiate by history alone and require histological characterization. Radiologically,

UC is often left sided with shallow mucosal ulcers extending down to the rectum with

small bowel sparing. Crohn’s is a discontinuous, full thickness disease, often with deep

penetrating ulcers sparing the rectum and commonly seen at the terminal ileum.

• Toxic megacolon: This can occur in any form of colitis, but is particularly prevalent

in UC. Uncontrolled fulminant colitis can lead to transmural involvement with rapid

dilatation of the large bowel. There are large fluid shifts and the patient is often toxic

and shocked. As a surgical emergency, it requires rapid identification and carries a

significant risk of mortality.

Named after Leo George Rigler, an American radiologist, the eponym ‘Rigler’s sign’ was

derived from his paper entitled ‘Spontaneous pneumoperitoneum: a roentgenologic sign

found in the supine position’.¹ Until 1941, the only documented sign of intraperitoneal

free gas was seeing crescenteric gas contrasted against the diaphragm and solid abdomi-

nal viscera on erect chest radiographs. Rigler described that is it possible to ‘observe both

the contour of the inner and outer wall of the bowel’¹ in supine positioning when there

is significant intraperitoneal free gas. This is also known as the ‘double wall sign’, and

is an abnormal finding unless the patient has undergone recent surgery or laparoscopy

(Figure 80.4).

227

CASE 81: PAIN IN THE LEFT WRIST FOLLOWING A FALL

History

A 65-year-old woman attends her local accident and emergency department following

a mechanical fall. While walking her dog this morning, she slipped on the icy pavement

and fell forward, putting out her left hand to break her fall. She heard a ‘crack’ and had

an instant sharp stabbing pain in her left wrist. Noticing an obvious deformity and expe-

riencing severe pain on all movements, she called her husband who collected her and

bought her to hospital.

She has a history of gallstone disease and a cholecystectomy. She went through the

menopause aged 55 years, and was on hormone replacement therapy for the following

6 years. She has never had a bone density scan or suffered any previous fractures. She

takes no regular medication and has never taken corticosteroids.

Examination

The triage nurse has requested a wrist X-ray (Figure 81.1).

Questions

• What does this X-ray show?

• What is the common mechanism of

injury and how is it treated?

Figure 81.1 Lateral radiograph of the left wrist.

229

ANSWER 81

Figure 81.1 is a lateral radiograph of the left wrist in an adult patient. There is abnormal-

ity seen in the distal radius with interruption of the normal smooth cortical line, and a

linear cortical breach extending horizontally through the distal radius. There is loss of

normal alignment with the distal radius fragment dorsally angulated by approximately

30 degrees. The radiocarpal joint is not involved but the carpal bones are displaced pos-

teriorly with associated overlying soft tissue swelling. It is normal practice to look at the

wrist in two views.

This anterior-posterior (AP) view of the same patient (Figure 81.2) confirms a commi-

nuted fracture of the distal radius with dorsal angulation of the distal fragment. There

is also a fracture of the ulna styloid with medial displacement of the distal fragment

associated with soft tissue swelling. No other bony injury is seen, most importantly to the

scaphoid. There is no radiographic evidence of scapholunate dislocation. These features

are in keeping with a complex Colles’ fracture to the left wrist.

Figure 81.2 AP radiograph view of the left

wrist.

This type of wrist fracture is named after Abraham Colles, an Irish surgeon from Dublin

(1773-1843). A Colles’ fracture is the commonest fracture to the forearm and is usually

sustained from a mechanical fall. The patient uses an outstretched hand to break the

fall, with the radius fracturing horizontally approximately 2 cm from the articulating

surface. The patient’s bodyweight forces the distal fracture fragment dorsally and com-

monly fractures the ulna styloid in the process. The nature of the injury predisposes the

osteoporotic elderly and active young patients (skateboarders, snowboarders) to this type

230

of fracture. Reduction of the fracture is essential to reduce the long-term risks of fused

misalignment, deformity, reduced range of movement and joint osteoarthritis. This is

most commonly done in the accident and emergency department under sedation and

local anaesthetic (Bier’s block). The wrist is reduced and temporarily placed in a cast, held

in palmar flexion with ulna deviation to maintain the reduction. Orthopaedic assessment

in the fracture clinic may leave undisplaced fractures in a cast with no further treatment,

however significant deformity usually requires surgical fixation, taking into account age,

hand dominance, occupation, radial variance, intra-articular extension and dorsal tilt

(>20 degrees).

The four commonest adult wrist fractures to recognize are shown in Figure 81.3.

Colles fracture

Smith fracture

Figure 81.3 Adult wrist fractures.

Reproduced from Reference 1

with permission.

Barton fracture

Chauffeur fracture

In addition to Colles’ fracture, these include:

• Smith fracture: Commonly called the reverse Colles’ fracture, this is commonly seen

in older osteoporotic patients who fall onto a clenched fist. A horizontal fracture to

the distal radius is sustained with volar angulation of the distal fragment.

• Barton fracture: This injury, also sustained by falling on an outstretched hand, frac-

tures the radial head vertically with dorsal angulation to the distal fragment. This has

intra-articular extension and is associated with carpal dislocation.

• Chauffeur fracture: Sudden ulnar deviation and dorsiflexion causes an avulsion frac-

ture to the radial styloid with lateral displacement of the fracture fragment. Associated

with lunate dislocation, these fractures were commonly sustained by chauffeurs when

an automobile backfired during a hand crank start.

KEY POINTS

• A Colles’ fracture is the commonest fracture of the forearm and is usually sustained by

falling on an outstretched hand.

• Fracture reduction is essential to reduce the risk of long-term osteoarthritis.

• Fracture clinic assessment is integral in the follow-up of all fractures.

Reference

1. Dahnert, W. (2011) Radiology Review Manual, 7th edn. Philadelphia: Lippincott Williams and

Wilkins.

231

CASE 82: A KNOWN CASE OF INFLAMMATORY BOWEL DISEASE

History

A barium follow-through study has been requested on a 22-year-old woman who has a

history of Crohn’s disease. She presented 2 days earlier with abdominal pain localized to

the left lower quadrant and occasional diarrhoea. She denies vomiting and is still passing

flatus freely. Despite taking her Crohn’s medication regularly, she feels this is an acute

flare-up of her disease and sought medical attention.

Examination

Examination reveals a patient who is comfortable at rest with normal observations. Her

abdomen is generally soft on palpation but there is local guarding and tenderness in the

left iliac fossa. Per rectal examination does not demonstrate rectal blood.

Investigations show an elevated white cell count (90 per cent neutrophils) with normal

renal and liver function tests. Her C-reactive protein is 160 mg/L.

An abdominal radiograph did not demonstrate bowel obstruction and a barium follow-

through study is requested to assess her bowel mucosa and look for fibrotic strictures

(Figure 82.1).

Figure 82.1 Barium follow-though.

Questions

• How is this procedure performed and what does it demonstrate?

• What other imaging modalities are used to diagnose and follow-up patients with

Crohn’s disease?

• What are the extra-intestinal manifestations of Crohn’s disease?

233

ANSWER 82

This is a single image of a barium follow-though study, acquired with the patient in a

prone position and centred on the right lower quadrant. There is good opacification of

the small bowel, and contrast appears to have passed freely into the large bowel with

opacification of the descending colon. This image demonstrates a 25 cm stricture of the

terminal ileum, with the adjacent caecal pole also appearing abnormal and oedematous.

There is small bowel loop separation in the right lower quadrant, probably related to lym-

phoedema of the bowel wall and adjacent fibrofatty proliferation, however an inflamma-

tory mass lesion (e.g. abscess) needs to be excluded. There is no prestenotic dilation and

the appearance of the remaining small bowel is normal. The findings are in keeping with

active inflammatory stricture related to Crohn’s disease, and a computed tomography (CT)

abdomen and pelvis is recommended to exclude a drainable collection.

Local hospital policy dictates the exact procedural technique of a barium follow-through

study: a patient is required to drink a set volume of radio-opaque barium, often diluted

with water and mixed with a prokinetic agent (e.g. metoclopramide) to promote rapid

transit through the bowel. The barium is screened though the small bowel under fluoros-

copy, and sequential images are obtained at different points in time. The patient is often

imaged in the prone position to splay the bowel loops and reduce composite shadowing

from overlying loops of bowel. Focal compression can improve visualization as demon-

strated in this image, with the compression paddle highlighting the area of tapered nar-

rowing at the terminal ileum.

As well as small bowel follow-through studies, there is also a role for both CT and mag-

netic resonance imaging (MRI). A CT scan is quick to perform and usually accessible

24 hours per day, but it carries a significant radiation exposure and Crohn’s patients

are often young. CT is employed in the acute setting to characterize the extent of acute

inflammation and also to exclude abscess formation (Figure 82.2).

Figure 82.2 Axial CT scan.

A CT scan of the same patient, acquired at the level of the terminal ileum following intra-

venous and oral contrast administration was performed. It confirms an acute inflamma-

tory reaction centred on the terminal ileum and caecal pole with bowel wall thickening,

mucosal hyperenhancement and perinephric fat stranding with small volume pericolic

lymph nodes seen. There is no evidence of an inflammatory mass lesion or drainable

collection.

234

MRI is preferable for the long-term follow-up of Crohn’s disease patients, and has a high

sensitivity for disease evaluation without exposing the patient to ionizing radiation. MRI

has good soft tissue contrast and provides further information to differentiate between

fibrosis and inflammation.¹ This can dictate whether a patient continues medical treat-

ment or requires surgery. However, MRI is expensive and time consuming to perform and

does not provide accurate mucosal detail obtained in a follow-through study.

Figure 82.3 is a single image from an MRI half Fourier acquisition single shot turbo spin

echo (HASTE) sequence of the same patient taken 6 months later, and demonstrates a

fibrotic stricture of the terminal ileum measuring approximately 6 cm, with no evidence

of active inflammation.

Figure 82.3 Axial MRI image from HASTE

sequence.

Crohn’s disease is an inflammatory condition that can affect the bowel anywhere from

the mouth to the anus. Gastrointestinal symptoms include diarrhoea, rectal bleeding, mal-

absorption and abdominal pain. Patients suffer from bowel strictures causing obstruction,

adhesion formation and fistulation, often resulting in surgery. As well as an increased

risk of malignancy, patients have a range of extraintestinal manifestations (Table 82.1).

Table 82.1 Extraintestinal manifestations of Crohn’s disease

Hepatobiliary

Fatty liver

Gallstone disease

Pancreatitis

Genitourinary

Urolithiasis

Renal amyloidosis

Musculoskeletal

Clubbing

Hypertropthic osteoarthropathy

Avascular necrosis

Erythema nodosum

Uveitis

Growth retardation (childhood onset)

235

CASE 83: A TOURIST FROM NEW ZEALAND

History

A 44-year-old woman attends the accident and emergency department with a painful leg.

She is a tourist on holiday, and flew in from New Zealand on a 23-hour flight arriving

2 days ago. Since landing in the UK, her left leg has developed an achy pain with asso-

ciated swelling and erythema. It has become increasingly difficult to walk, and despite

analgesia with elevation of the leg her symptoms have not resolved. She is alarmed by

the swelling and attended hospital with near complete immobility due to the pain.

She is normally a fit and healthy individual with no significant medical history. Apart

from occasional homeopathic remedies for insomnia, she is taking no regular prescribed

medication other than the oral contraceptive pill.

Examination

On examination there is swelling of the left ankle, calf and thigh with marked tenderness

in the calf muscles and some tenderness medially in the thigh. There is some redness of

the leg. There is no knee joint effusion and peripheral pulses are present.

As part of her investigations, a lower limb ultrasound is organized with the radiology

department (Figure 83.1).

Figure 83.1 Ultrasound.

Questions

• What does this ultrasound image demonstrate?

• How does ultrasound work?

• What are the strengths and limitations of ultrasound?

237

In summary, there is echogenic thrombus seen within the left SFV with reduced pat-

ency, compressibility and flow in keeping with a deep vein thrombosis (DVT). The pos-

sible complications are pulmonary embolism and post-phlebitic problems in the limb.

Anticoagulation is indicated. The risk factors in this case are the long flight and the oral

contraceptive pill. The oral contraceptive pill should be stopped, with appropriate con-

traceptive advice, and anticoagulation would normally be continued for 6 months with a

first thrombus and an identified precipitant.

Ultrasound is the use of sound waves to image the human body. The sound waves are

of such high frequency that they are inaudible to the human ear (e.g. 2-20 MHz). An

ultrasound probe is designed to convert an electrical signal into acoustic energy and does

so by utilizing the unique properties of piezoelectric crystals (most commonly microcrys-

talline lead zirconate titanate (PZT)). The ultrasound probe comprises a compressed layer

of PZT, which is coated in silver to allow electrical conduction. Passing an alternating

electrical current causes the PZT to expand and contract with the production of a sinu-

soidal sound wave of a particular frequency and wavelength. The shape of the ultrasound

probe and a rubber-coated window can focus the sound wave, allowing an operator to

control its direction.

The sound waves do not pass through the body freely, and tissues of differing density

cause the beam to be reflected back towards the probe. The degree of sound wave trans-

mission through a tissue before it is reflected is dictated by the acoustic impedance of the

tissue through which it is passing. Subtle density changes (e.g. within soft tissue) cause

the reflected ‘echoes’ to return to the probe at different times. The returning sinusoidal

sound wave compresses the PZT, which converts the acoustic echo back into electrical

energy and allows complex computer programs to form a picture on the operator’s screen.

When there is a sudden density change (e.g. muscle to bone/muscle to gas) the majority

of the sound wave is either transmitted or reflected and no images beyond this density

interface can be generated. This limits the use of ultrasound in imaging the lungs or deep

to bone.

Each probe has a fixed frequency, with a higher frequency returning more echoes over

a period of time and forming an image of superior resolution compared to probes of a

lower frequency. Unfortunately, the acoustic impedance of higher frequency and shorter

wavelength sound waves, limits the depth they can travel. Higher frequencies are there-

fore recommended for the imaging of superficial pathology (e.g. a subcutaneous lump),

while deeper imaging (e.g. abdomen) requires a probe of increased wavelength, and the

reduced frequency allows only for an image of reduced resolution. As with many other

aspects of radiology (e.g. CT dose versus noise), image resolution and depth penetration

is a trade-off.

As an imaging modality that does not involve the use of ionizing radiation, ultrasound

is preferred, if appropriate, to CT or X-ray. Some of the strengths and weaknesses of

ultrasound are listed in Table 83.1.

239

Table 83.1 Strengths and weaknesses of ultrasound

Strengths

Weaknesses

• No ionizing radiation: This is especially

• Operator dependent: Experience may dictate

important in the young people and pregnant

a more accurate report

women

• Cheap: Compared to a CT or MRI scanner,

• Body habitus: It is more difficult to generate

ultrasound machines are inexpensive

a diagnostic image in larger people

• Readily available: No patient preparation or

• Density changes: Images are limited by

other healthcare professionals required

bone, bowel gas and normal aerated lung

• Real time: Allows for functional imaging

(e.g. contrast enhancement) and needle

guidance for biopsy procedures

• Portable: Ultrasound machines can be taken

to immobile patients (e.g. ITU)

KEY POINTS

• Ultrasound has a high sensitivity for the diagnosis of a DVT and carries no risk of

ionizing radiation exposure to the patient.

• Ultrasound assesses compressibility, patency and flow of the deep venous system.

• The major limitations of ultrasound are operator dependence and patient body habitus.

240

CASE 84: SPONTANEOUS NOSE BLEEDS IN A YOUNG PERSON

History

A 14-year-old boy is referred to the interventional radiology department following an

ear, nose and throat (ENT) multidisciplinary meeting (MDM). He complains of a 6-week

history of epistaxis that has been increasing in frequency, currently with approximately

eight episodes of bleeding per day. No predisposing factors are to be found on history

and the spontaneous bleeds can occur at any time. The worst bleeds are at night and

he recently reports a single episode when he woke from sleep feeling as though he was

choking from a spontaneous episode of bleeding. At that time the bleeding lasted more

than 30 minutes and required hospital attendance for nasal packing. He has never needed

a blood transfusion.

Examination

On review by the ENT registrar on call at the accident and emergency department, initial

screening bloods were unremarkable but the patient was kept in hospital overnight for

observation. The next morning the nasal packing was removed and direct visualization

with a flexible nasendoscope revealed an area of friable soft tissue abnormality on the

right side. The patient was referred for a contrast-enhanced computed tomography (CT)

scan, which revealed an avidly arterially enhancing soft tissue mass in the post-nasal

space with extension into the retroantral region. The pterygopalatine fossa was widened

and a diagnosis of juvenile angiofibroma was made with supply from the right spheno-

palatine artery. The patient was discussed at the ENT MDM and referred for embolization

under the interventional radiologists (Figure 84.1).

Figure 84.1 Digital subtraction angiography.

Questions

• How was this procedure performed?

• How are catheters and sheaths sized?

• What embolization materials are available?

241

ANSWER 84

This case is designed to inform the reader of a few of the devices that are available to an

interventional radiologist and the application of them. It also highlights the importance

of having a good understanding of vascular anatomy and patient preparation.

The patient was admitted electively to the paediatric ward and the case performed under

general anaesthesia. The right common femoral artery was punctured under ultrasound

guidance with local anaesthetic cover by a micro-puncture needle. A 0.018″ Mandrel was

passed into the common iliac artery and a 4 French (Fr) sheath was inserted at the punc-

ture site. A 0.035″ standard wire was passed into the aortic arch over which was passed

a directional catheter. The wire was exchanged for a 0.035″ hydrophilic angled wire and

the catheter/wire combination was used to selectively cannulate first the brachiocephalic

trunk followed by the common carotid and external carotid arteries. A selective hand-

injected angiogram was performed to characterize the vascular anatomy (Figure 84.2).

Maxillary artery

Endotracheal tube

Facial artery

Lingual artery

Figure 84.2

Having achieved a stable position with the guide catheter, a 2.8 Fr microcatheter set was

used to cannulate the right maxillary artery and advance it for selective cannulation of

the sphenopalatine artery. Position was confirmed with angiography and embolization

was performed with 500-700 μm polyvinyl acetate (PVA) particles until haemostasis was

achieved. There were no unexpected complications and post procedure the patient was

cared for by ENT with a successful outcome and no further epistaxis reported.

Catheters and sheaths (Figure 84.3) are the basic tools of an interventional radiologist,

and a good understanding of how their size is measured is essential for effective use of

a catheter/sheath combination. A sheath is used to secure vascular access and provide

stability for the safe passage and manipulation of a catheter through it. They are sized

242

Figure 84.3

according to the French gauge system (Fr) where 1 Fr is 0.33 mm. The bigger the French

size the larger the diameter, and this is not to be confused with the needle gauge system

where the diameter of a needle is 1/gauge (therefore the larger the gauge the smaller the

needle). The French size of a catheter refers to its outer diameter, while when referring to

a sheath the French size corresponds to its inner diameter. Therefore a 4 Fr catheter will

pass through a 4 Fr sheath.

Embolization procedures are minimally invasive and use the vascular channels of the

body to deliver a particular agent to the site of pathology. There are many emboliza-

tion products on the market, and the most appropriate one is selected depending on the

outcome that needs to be achieved. They can be either permanent or temporary but are

grossly classified into four categories:

• Liquid agents: This is a form of liquid glue that can be injected via a catheter to flow

through complex vascular anatomy and solidify, thereby reducing arterial or venous

blood flow. They are commonly used in the treatment of arterio-venous malforma-

tions (AVMs).

• Particle agents: This type of embolization material is used in small arteries or pre-

capillary arterioles. They come in a range of sizes (approximately 50-1200 μm) and are

predominantly permanent. They have both a mechanical property and clump together

to reduce blood flow, but also deliberately induce inflammation to promote clotting.

The major disadvantage is that they carry a risk of unwanted distal embolization if

not targeted specifically within the blood vessel of choice.

• Coils: These are lengths of platinum or stainless steel that are extruded out of a cath-

eter into a high-flowing blood vessel. They are designed to deliberately coil within

the vessel and often carry Dacron wool feathers, which slow blood flow causing a

mechanical clot and haemostasis. It is a form of permanent embolization and is com-

monly used in AVMs, testicular vein embolization and in uncontrolled haemorrhage.

• Plugs: This is a form of permanent embolization. The plug is appropriately selected for

size and then delivered to a vessel through a catheter in a collapsed form. Its delivery

can be highly accurate and it is re-expanded within the vessel before detachment to

cause a mechanical embolization.

KEY POINTS

• Optimal patient preparation and procedural planning is of paramount importance in

any interventional procedure.

• An excellent understanding of expected and aberrant anatomy is essential.

• In the French gauge system, 1Fr is equivalent to 0.33 mm in diameter.

243

CASE 85: ABDOMINAL WEIGHT GAIN AND DISTENSION DESPITE

DIETING

History

A 44-year-old Afro-Caribbean woman has been referred for assessment. She complains

of gradual abdominal distension over the last few years. Until recently this was not

associated with abdominal pain outside of her normal menstrual periods, but over the

last month she has had a constant achy pain in her stomach. She denies any chance of

pregnancy and reports no change in her bowel habit. She has been gaining weight over

the last few years despite activity and dieting.

Examination

Examination reveals a distended but soft abdomen, with a fullness centrally that is ten-

der on deep palpation. This has clear examination margins unrelated to other abdominal

viscera and does not move on respiration. Haematinic studies reveal a slight microcytic

anaemia with normal renal, thyroid and liver function parameters.

An abdominal ultrasound study organized by her general practitioner (GP) had demon-

strated the presence of a large soft tissue/cystic mass extending up from her pelvis. The

patient was referred following an magnetic resonance imaging (MRI) study (Figure 85.1).

Figure 85.1 Sagittal T2-weighted MRI scan.

Questions

• What is this examination and what is the main abnormality?

• Can you classify the type of abnormality seen?

• How are these lesions normally diagnosed and treated?

245

ANSWER 85

Figure 85.1 is a T2-weighted image of the pelvis from an MRI study acquired in the

sagittal plane. There is a broad-based pedunculated lesion arising from the uterine fun-

dus. This measures approximately 14.5 × 8.4 cm in maximal dimensions and is of pre-

dominantly low signal intensity. Subsequent post-gadolinium imaging demonstrated avid

enhancement. When comparing it to neighbouring tissue types, the lesion has slightly

lower signal characteristics to the adjacent myometrium of the uterus, confirming the

diagnosis of a subserosal fibroid. A prominent leash of blood vessels around the right

side of the fibroid appears to feed the fibroid. The fibroid also contains a well-defined

unilocular central cystic component measuring 9.6 × 7.0 cm. The fluid within the cystic

component is hyperintense on T1-weighted images, in keeping with haemorrhagic degen-

eration. The cystic component does not demonstrate any vascularity.

Uterine fibroids result from benign proliferation of the smooth muscle of the myo-

metrium, and can therefore interchangeably be referred to as uterine leiomyomas. They

are the commonest gynaecological malignancy, and have an increased incidence in Afro-

Caribbean people with approximately 50 per cent of all women affected.¹

Dependent on oestrogen for growth, it is unusual for women to be diagnosed with fibroid

disease in the post-menopausal period or before the age of 30 years, with the exception

of younger pregnant women where changes in the oestrogen : progesterone ratio can see

rapid fibroid growth in the first trimester. Fibroid size and multiplicity can vary, with the

commonest symptoms being pelvic pain, abdominal distension, dysmenorrhoea and men-

orrhagia. Fibroids large enough to distort the uterine cavity can be responsible for infer-

tility or miscarriage, and can also cause urinary frequency when pressing on the bladder

anteriorly. As a highly vascular tumour, if the fibroid size is such that it outgrows its own

blood supply, myxoid or haemorrhagic degeneration can occur as seen in Figure 85.2.

Figure 85.2 Axial T2-weighted MRI scan.

Their position in relation to the wall of the uterus allows for classification:

• Submucosal: Growth centred on the inner myometrium allows fibroids to project into

the uterine cavity.

• Intramural: The commonest subtype, with most patients remaining asymptomatic.

• Subserosal: Centred on the outer myometrium, these fibroids are exophytic and can

be pedunculated with increased risk of torsion or infarction.

246

The differential diagnoses associated with the symptoms of fibroid disease are wide,

and imaging is essential. Radiologists would advocate the use of ultrasound in the first

instance, as this is quick and easily accessible, with no radiation dose to the patient.

Optimal views of the uterus would be achieved with a transvaginal scan, although good

views of the uterus can be obtained transabdominally, ideally with a full bladder. The

role of computed tomography (CT) is limited and there is a significant radiation dose to

the radiosensitve pelvic organs.

On ultrasound, fibroids are usually seen as ill-defined rounded hypoechoic heterogeneous

lesions associated with distorted uterine architecture. The fibroids have similar ultrasound

appearances to the adjacent myometrium, and echogenic bands separating bundles of

smooth muscle can be delineated. The presence of calcification is common, demonstrated

by echobright foci within the fibroid with posterior acoustic shadowing. Doppler assess-

ment can demonstrate avid vascularity.

MRI is the gold standard imaging modality for accurate fibroid characterization. It can

provide clear zonal anatomy for surgical planning and reliably exclude cystic or haem-

orrhagic degeneration. Imaging sequences of MRI are out of the remit of this case and

fibroids can have a variety of appearances, however, fibroids are classically of low signal

on T2-weighted images and iso- or hypo-intense to myometrium on T1-weighted images.

Calcium would appear low signal on all sequences, with fibroid degeneration appearing

as high signal on T2. The degree of haemorrhage, myxoid or cystic degeneration can be

variable and is best reviewed on T1 for characterization.

Until the mid 1990s, the only treatment available for symptomatic fibroid disease was

surgery in the form of myomectomy or hysterectomy. These procedures carry significant

morbidity and require an inpatient stay. As an alternative, interventional radiologists can

now offer uterine artery embolization (UAE) to appropriate patients. This is a minimally

invasive technique, with selective cannulation of both uterine arteries via a percutaneous

groin puncture of the external iliac artery. Under direct fluoroscopic vision, embolization

material is instilled to selectively thrombose the uterine artery and deliberately infarct the

fibroid. This reduces tumour volume and improves patient symptoms over time, hopefully

avoiding the need for aggressive surgery.

Figure 85.3 Uterine embolization.

247

CASE 86: LEFT MID ZONE CRACKLES

History

A 35-year-old man is sent to the accident and emergency department by his general

practitioner (GP) after complaining of shortness of breath. The symptoms started 10 days

ago with a chesty cough, which has become productive of yellow/brown sputum over

the last week. He has also noticed increasing shortness of breath and reports a reducing

exercise tolerance to less than two flights of stairs. He is a smoker of 10 cigarettes per

week, with no relevant past medical or drug history.

On visiting the GP last week, some inspiratory crackles were heard on auscultation in

the left mid zone, and a diagnosis of a respiratory tract infection was made. He was pre-

scribed a course of amoxicillin but his symptoms have not resolved. He attended the GP

today for follow-up and was referred to the accident and emergency department.

Examination

On examination he appears short of breath at rest with use of accessory muscles. His

temperature is 38.6°C and he complains of left-sided chest pain on deep breathing.

Auscultation reveals coarse crackles in the left mid zone. A sputum sample is green and

blood stained. A chest radiograph has been arranged for further assessment (Figure 86.1).

Figure 86.1 Chest radiograph.

Questions

• What does the radiograph show and in which lobe is the pathology?

• Should we worry about the risk of radiation exposure if this patient needs follow-up

X-rays?

• Which radiological examinations carry the largest radiation exposure?

249

ANSWER 86

Figure 86.1 is an anterior-posterior (AP) chest radiograph of an adult male patient taken

in the erect position. It is adequately penetrated but slightly rotated to the right. There is

a patchy area of airspace opacification within the left lower zone that lies adjacent to the

left heart border obscuring the normal cardiomediastinal contour. Air bronchograms are

demonstrated in keeping with consolidation. They are caused by opacification of the lung

tissue around air-containing airways. The presence of a ‘silhouette sign’ and obscuration

of one part of the cardiomediastinal border can accurately localize the lung pathology

to a particular lobe. In a two-dimensional radiograph a cardiomediastinal border will be

lost when up against consolidated lung, but maintained when still lying adjacent to air-

containing lung. This is termed the ‘silhouette sign’. In this case, loss of the left heart

border with preservation of the hemidiaphragm is in keeping with the silhouette sign of

lingular consolidation. An annotated chest radiograph demonstrating the normal cardio-

mediastinal borders is shown in Figure 86.2.

LSV LSA

LSV = left subclavian vein

LSA = left subclavian artery

BCV SVC

BCV = brachiocephalic vein

Aorta

SCV = superior vena cava

AV = atrioventricular node

RA = right atrium

LAA = left atrial appendage

MPA

LV = left ventricle

SVC/Aorta

MPA = main pulmonary artery

LAA

Figure 86.2 Chest radiograph with borders annotated.

For lingular consolidation amoxicillin would not be the appropriate antibiotic and fol-

lowing adequate treatment, if the radiograph changes fail to resolve, further investiga-

tions to rule out an obstructive lesion might be indicated.

Several different types of radiation are used in diagnostic imaging, but the principal

radiation source, and the one that a patient is regularly exposed to, is X-rays. There

is an understandable inherent fear of radiation exposure, but the risks associated with

radiation exposure are only realized when there is absorption of energy by living tissue.

High-energy beams that pass straight through a person with no absorption are harmless,

but absorption causes free radical formation which directly damages cell DNA/RNA, lead-

ing to cell death or transformation. Unfortunately, it is the absorption characteristics in

250

human tissues of differing densities that allow a diagnostic picture to be produced. The

use of ionizing radiation is therefore strictly controlled through government regulations,

most notably the Ionising Radiation (and Medial Exposure) Regulations (IRMER) 2000.

The effects of radiation can be seen either in the exposed individual (somatic effects)

or may be realized in the offspring of an exposed individual. These types of effects are

termed hereditary and can be either deterministic or stochastic:

• Deterministic: Effects of radiation exposure are only seen when the amount of radia-

tion a patient is exposed to exceeds a certain level. Beyond this threshold, the likeli-

hood of detrimental effects rapidly increases, but below it, no risk is inferred.

• Stochastic: These effects do not recognize a threshold dose, with the risks of cancers

and genetic abnormalities sharing a linear relationship with the degree of exposure:

the greater the exposure, the greater the risk.

The types of abnormality seen depend on the type of tissue exposed, with some organs

of the body being more radiosensitive than others, for example, the reproductive organs

or lens of the eye. It is also important to recognize that we are inherently exposed to

natural radiation every day, mainly from cosmic rays and radon decay. The average

dose to the UK population per year from these natural sources is approximately 2.2 mSv.

Some areas of the United Kingdom have higher exposure (e.g. 7mSv in Cornwall) from

local geographical factors. We can use these figures as a benchmark to help assess the

risk of radiation exposure from diagnostic imaging when ordering an X-ray or computed

tomography (CT) scan. If the option of an imaging modality that does not expose the

patient to ionizing radiation is available and appropriate (e.g. magnetic resonance or

ultrasound), then this should be considered in the first instance. Radiation exposures are

listed in Table 86.1.

Table 86.1 Radiation exposures from various imaging modalities

Examination

Dose (mSv) Equivalent number Equivalent amount of

of chest X-rays

natural radiation

Chest X-ray

0.02

3 days

Skull X-ray

0.06

9 days

Lumbar spine X-ray

5 months

Abdomen X-ray

0.7

4 months

Barium enema

7.2

360

3.2 years

CT head

100

10 months

CT chest

400

3.6 years

CT abdo/pelvis

500

4.5 years

V/Q scan

6 months

By thinking in terms of the number of equivalent chest X-rays a patient is exposed to

during a single study, a doctor can gauge the risk/benefit of different diagnostic inves-

tigations. Fluoroscopy studies carry the greatest dose, but are very operator dependent,

with variable degrees of radiation exposure. Although many barium investigations are

being replaced by CT studies (e.g. enemas), fluoroscopy activity is increasing overall with

the advancement of endovascular intervention techniques. CT is the ‘workhorse’ of a radi-

ology department and carries significant radiation exposure risk. Although collimation

and dose-reduction techniques are improving, if possible, always consider an alternative

method of answering the diagnostic question. For example, if the patient is low risk, a

251

CASE 87: TRAUMATIC INJURY TO A FARMER’S FOOT

History

A 45-year-old farm worker is bought to hospital by his wife. While changing the wheel of

his tractor earlier today, the jack collapsed and the tyre landed on his left foot before roll-

ing off. He felt an immediate sharp and stabbing pain which was exacerbated by walking.

His foot began to swell despite ice and elevation. Worried that he may have fractured a

bone they attended the minor injuries unit that evening.

He has no relevant past medical history but is a smoker of 20 pack-years.

Examination

Examination reveals a swollen left foot with bruising centred on the plantar arch. The

patient is in continued discomfort, with the medial aspect of the foot being most tender

over the first metatarsal. He is sent for a foot radiograph before further management is

planned (Figure 87.1).

Questions

• What injury does this radiograph show?

• What joint and ligament is involved?

• Why is it important to recognize this

injury?

Figure 87.1 Anterior-posterior (AP)

radiograph of foot.

253

ANSWER 87

In a normal anterior-posterior (AP) radiograph of a foot, the medial aspect of the second

metatarsal should align with the medial margin of the middle cuneiform. Figure 87.1

demonstrates an AP weight-bearing radiograph of the left foot. There is malalignment

of the Lisfranc joint, with a homolateral 3 mm slip of the second to fifth metatarsals. No

obvious fracture is seen and the remaining bones of the mid- and forefoot are intact

and correctly located. These features are in keeping with a Lisfranc dislocation, and the

patient should be referred to orthopaedics for further management.

The Lisfranc joint separates the bones of the midfoot, comprising the cuneiform and

cuboid bones, from the metatarsals of the forefoot. Each cuneiform bone articulates with

its first, second and third metatarsal, respectively, with the fourth and fifth metatarsals

articulating with the cuboid bone. Stability of the joint is maintained by complex liga-

ments found on the plantar surface, which maintain alignment when weight-bearing.

These ligaments are subject to significant shear forces on every step a person takes, and

are put under increased pressure in athletes. The largest ligament is the Lisfranc liga-

ment, which originates from the lateral aspect of the medial cuneiform bone, and inserts

into the medial aspect of the second metatarsal. It is primarily responsible for stability

of the whole joint, and maintains the plantar arch while preventing the second to fifth

metatarsals slipping laterally when walking.

Following injury, the Lisfranc ligament may either be stretched (Lisfranc sprain) or com-

pletely torn. Joint stability and alignment is lost, causing diastasis between the first and

second metatarsals and dislocation of the Lisfranc joint. Patients present acutely with soft

tissue swelling, plantar bruising and pain on weight-bearing. Special attention should be

given to those patients with sensory peripheral neuropathy (e.g. alcoholics and diabetics).

The injury is sustained either through longstanding repetitive strain placed upon the

ligament (e.g. athletes), or from a direct axial load forcing the foot downwards while in

rotation. The latter is often associated with bone fractures in combination with Lisfranc

dislocation. When suspected, a patient should be referred for orthopaedic assessment with

further imaging in the form of computed tomography (CT) to look for associated frac-

tures (Figure 87.2), and magnetic resonance imaging (MRI) to assess ligament integrity.

Without correction, normal biomechanics of the foot are lost, and the patient will develop

irreversible osteoarthritic change with eventual incapacitating disability on a background

of chronic pain.

Figure 87.2 Unenhanced coronal CT image

with bone windowing showing a bony

fragment in between the first and second

metatarsal bases indicative of a Lisfranc

ligament rupture.

254

CASE 88: AN ACCOUNTANT WITH ABDOMINAL PAIN

History

A 37-year-old accountant has been referred to your outpatient clinic by his general

practitioner (GP). He complains of vague abdominal discomfort, which is central, colicky

and intermittent. He has been having these symptoms for as long as he can remember

and was thought to have irritable bowel syndrome. They have recently been increasing

in frequency and his new GP decided to investigate them further. There are no predis-

posing factors and he has tried several dietary changes with no resolution of symptoms.

He denies any weight loss, change in bowel habit or vomiting, but suffered attacks on a

weekly basis now. The pain subsides spontaneously after a few hours with no sequelae.

There is no relevant past medical history. He does not take any regular medication and

denies allergy. He is a non-smoker, does regular exercise and lives with his wife and

child.

Examination

Nothing abnormal was found on examination. A set of blood results taken last month

are normal, and he has recently had a barium follow-through investigation (Figure 88.1).

Figure 88.1 AP image from barium follow-through study.

Questions

• Describe the barium study.

• What is the abnormality demonstrated?

• What are the complications of this condition?

257

ANSWER 88

This is a single anterior-posterior (AP) image from a barium follow-through study, cen-

tred on the abdomen and pelvis. There is good contrast opacification of the stomach

with normal distended appearances and no evidence of a filling defect. Barium is seen

to pass freely into the duodenum and jejunum on this 15-minute film, with no evidence

of stricture or obstruction. The pylorus and proximal duodenum are seen in the expected

position, but the opacified distal duodenum fails to cross the midline, instead remaining

on the right of the abdomen. The duodenal-jejunal (DJ) junction is abnormally located

within the right upper quadrant, with opacified jejunum appearing to continue on the

right side. Delayed images are required to see the position of the remaining small bowel

and caecal pole.

Figure 88.2 shows an image from the same patient taken at 80 minutes following inges-

tion of barium and demonstrated continuation of the entire small bowel to the right of

the midline. There is no evidence of stricture or obstruction. The caecal pole is located

within the pelvis, but is medial to its expected position in the right iliac fossa. The hepatic

flexure is abnormally positioned and lies within the left upper quadrant, with the entire

large bowel seen to lie on the left side of the abdomen. These features indicate a diagnosis

of malrotation.

Figure 88.2 Subsequent image from barium

follow-through.

During embryological development the primitive mid- and hindgut move out of the

abdominal cavity and normally rotate 270 degrees anticlockwise on a mesentery around

the central omphalomesenteric axis. This twisting movement allows the gut to pass under

the primitive superior mesenteric vessels as they form, before re-entering the abdomen.

The DJ flexure is then fixed to the base of the left hemidiaphragm by the ligament of

Treitz, and the caecal pole is secured in the right lower quadrant.

If the primitive gut is secured to a mesentry that is shorter than usual, the gut cannot

complete its full rotation, leaving the caceal pole and DJ junction in anatomically abnor-

mal positions. This is termed ‘malrotation’, and is best diagnosed with a barium follow-

258

through study, to identify the abnormal peritoneal fixation from the position of the bowel

loops. On a CT scan, the position of the superior mesenteric vessels is reversed, with the

superior mesenteric artery (SMA) positioned to the right of the superior mesenteric vein

(SMV). Imaging studies demonstrate a variety of appearances depending on how much

of the 270 degrees the bowel rotated before fixation, with a right-sided duodenum and

jejunum being the commonest finding. Patients are often symptomatic as neonates and

children, suffering from recurrent abdominal pain, distension and vomiting. Failure of

the primitive gut to rotate at all results in the entire small bowel on the right side of

the abdomen with the large bowel on the left, as in this case. These patients with non-

rotation often present as adults, and describe a history of mild intermittent abdominal

pain for as long as they can remember.

A short mesentry predisposes children to the complication of midgut volvulus. Most

commonly presenting in the first 3 weeks of life, children present with bilious projectile

vomiting and abdominal pain. This is a medial emergency and can lead to bowel infarc-

tion and death. Its characteristic features on a barium study demonstrate malrotation with

a spiralling ‘corkscrew’ appearance to the bowel distal to the obstruction (Figure 88.3).

Figure 88.3 Midgut volvulus.

KEY POINTS

• Oral contrast fluoroscopy studies have a high sensitivity for detecting malrotation.

• Normal embryological development involves a 270 degree anticlockwise rotation

around a central omphalomesenteric axis.

• On CT scans, check the position of the SMA in relation to the SMV in cases of

suspected malrotation.

259

CASE 89: PAIN IN A WOMAN WITH BREAST CANCER

History

A 57-year-old woman attends the hospital for a computed tomography (CT) scan. She

was diagnosed with breast cancer 3 years previously and was successfully treated with a

right mastectomy, radiotherapy and chemotherapy. Following breast reconstruction last

year, a routine CT scan demonstrated no assessable disease and the patient was offered

a clinic appointment for 6 months’ time. Recently she has noticed some increasing pain

the right upper quadrant of her abdomen and reported unexpected weight loss of over

2 kg. Informing her hospital consultant via telephone, the patient was asked to attend

hospital for a blood test and repeat CT scan of the chest and abdomen. She is due to see

the consultant in clinic tomorrow.

Examination

On the CT scan you find evidence of post-surgical change within the reconstructed right

breast with no assessable disease above the diaphragm. Abdominal review demonstrates

multiple areas of low attenuation within the liver, which are new compared to the previ-

ous CT, in keeping with hepatic metastases. Both kidneys are unobstructed and there is no

evidence of portal vein thrombosis. To complete the report, you review the bony skeleton

reconstructed in the sagittal plane for improved image interpretation (Figure 89.1).

Figure 89.1 Sagittal reconstruction from a CT

scan.

Questions

• What does the CT scan demonstrate?

• What are the common tumour types that cause this appearance?

• What further radiographic investigations should be considered?

261

ANSWER 89

This image is a sagittal reconstruction from a CT scan centred on the lower thoracic,

lumbar and sacral spine. It has been windowed to improve bony resolution. It demon-

strates multiple areas of well-defined reduced attenuation and loss of the normal bony

architecture throughout the vertebral column and sacrum with evidence of posterior ele-

ment involvement. They have a narrow zone of transition and are surrounded by areas

of ill-defined sclerosis. The vertebral column retains a normal alignment and there is no

loss of vertebral body height to suggest vertebral collapse. Within the limits of this single

image, the cord appears capacious throughout, although review of the whole image series

is recommended. The findings are in keeping with multilevel lytic bone metastases.

Secondary bone deposits are approximately 100 times more common than primary bone

tumours.¹ Spread from the tumour haematogenously, via the lymphatics or through direct

invasion, they have a predilection for parts of the skeleton with high marrow content,

affecting the axial skeleton more often than the ribs and skull. Their presence alters the

bone integrity, and patients are at increased risk of fracture despite normal physiological

loads being applied, known as ‘pathological fractures’. This is most marked in the spine,

where vertebral compression fractures can cause spinal canal stenosis from retropulsed

bone fragments, which can encroach on the spinal cord causing compression and neuro-

logical compromise. Spinal cord compression is a neurosurgical emergency.

Depending on cell type, tumour deposits upregulate either osteoclastic or osteoblastic

activity, giving characteristic radiographic appearances. Those metastases with osteo-

clastic activity cause bone lysis, with soft tissue deposits destroying the adjacent bone

and reducing the structural integrity. On X-ray, the bone can appear ‘moth-eaten’ and

destroyed, with pain being the commonest clinical symptom. Osteoblastic metastases

cause bone sclerosis, with new bone formation appearing as areas of increased density.

The involved bones retain their normal morphology, but the heterotrophic bone has

abnormal trabecular architecture, reducing the overall bone integrity. To confuse mat-

ters, some tumour types have metastases with both lytic and sclerotic components, and

lytic bone metastases become sclerotic following treatment (e.g. radiotherapy or chemo-

therapy). A few metastases can also cause characteristic bone expansion and the common

appearances are listed in Table 89.1.

Table 89.1 Common tumour appearances

Tumour type

Lytic

Sclerotic

Expansile

Lung

Breast

Prostate

Kidney

Bowel

Lymphoma

Carcinoid

Thyroid

Bladder

Bone metastases are more likely to be multiple than solitary, and a combination of

modalities such as plain X-ray, CT and MRI are used to assess bony metastatic disease.

Bone scintigraphy, where radioactive phosphate particles are administered intravenously,

is often appropriate in characterization of disease distribution and treatment response.

262

The whole body is imaged, and the normal physiological bone appearances are disturbed

by areas of intense tracer uptake from sclerosis, or areas of photopenia from bone lysis.

It is highly sensitive with relatively low radiation exposure, and is useful to localize areas

of possible disease for further assessment.

Figure 89.2 shows a bone scintigraphy study from a patient with a prostate specific

antigen (PSA) of >2000, with increased tracer uptake seen in the skull, both shoulders,

shaft of both humeri and femora. There is also diffuse uptake of tracer noted in multiple

ribs bilaterally as well as in multiple vertebrae at multiple levels. The proximal tibia, pel-

vis and right sterno-clavicular joints are also involved. Both kidneys are not visualized

suggesting a ‘superscan’ consistent with extensive bone metastases from an underlying

diagnosis of prostate cancer.

Figure 89.2 Bone scintigraphy images.

KEY POINTS

• Bone metastases can be either lytic, sclerotic or mixed

• CT has a high sensitivity for resolving bony abnormality.

•

Bone scintigraphy can be employed to assess the extent of bone involvement.

Reference

1. Dahnert, W. (2011) Radiology Review Manual, 7th edn. Philadelphia: Lippincott Williams and

Wilkins.

263

CASE 90: HEADACHE AND VISUAL FIELD DEFECTS

History

A 48-year-old man has been referred by his general practitioner (GP) for further man-

agement. He complains of weight gain, tiredness and headache over the last few months

with no resolution of symptoms despite diet and analgesia. Initially thought to be stress

related, a screening blood test revealed normal biochemical markers other than a slightly

low T4, low thyroid stimulating hormone (TSH) and low testosterone.

There is no relevant medical history. He is not taking regular medication and is a non-

smoker. Living at home with his wife and children, he has taken several sick days recently

because of his symptoms.

Examination

Examination reveals a tired looking Caucasian man in no obvious discomfort. His body

mass index (BMI) is 26 (previously recorded at 23). He is afebrile, normotensive and

with a regular pulse of 56 beats per minute. Cardiovascular, respiratory and abdominal

examination is normal. On neurological examination, visual field assessment reveals a

bitemporal hemianopia. A thyroid ultrasound scan and chest radiograph were normal,

and a cranial computed tomography (CT) scan was arranged (Figures 90.1 and 90.2).

Figure 90.1 Unenhanced axial CT scan.

Figure 90.2 Enhanced sagittal CT scan.

Questions

• What does the CT scan show?

• Is there a differential for these appearances and what would you do next?

• What is the cause of the patient’s symptoms and biochemical abnormality?

265

ANSWER 90

The two images of the same patient are taken from a cranial CT study before and after

the infusion of intravenous contrast. The axial image (Figure 90.1) is unenhanced and

acquired at the level of the cavernous sinus. The patient’s head is slightly tilted to the

right. Within the suprasellar space there is a soft tissue mass measuring approximately

20 × 17 mm which is well defined and isodense to the neighbouring brain tissue. It is of

homogenous attenuation and displays curvilinear rim calcification. It is expanding the

sellar turcica and splaying the cavernous sinus laterally. There is normal grey/white

differentiation and no evidence of acute haemorrhage. The second image (Figure 90.2)

is taken following the infusion of intravenous contrast and reformatted in the coronal

plane. The soft tissue mass demonstrates avid uniform enhancement centred on the pitui-

tary fossa with suprasellar extension towards the optic chiasm and third ventricle. The

sella is expanded as before but there is no obvious breach of the sella floor or extension

into the sphenoid sinus. Within the limits of these images, the basal cisterns are preserved

throughout and there is no evidence of hydrocephalus or tentorial herniation.

The differential for a pituitary mass with suprasellar extension includes:

• pituitary adenoma;

• carotid artery aneurysm;

• meningioma;

• pituitary metastasis;

• pituitary lymphoma;

• pituitary abscess;

• Rathke’s cleft cyst.

From this differential list, pituitary abscess and Rathke’s cleft cyst can be discounted

as the pituitary mass is of homogeneous soft tissue density and the patient is not clini-

cally septic or unwell. Pituitary metastasis and lymphoma are very rare and would be an

unlikely diagnosis considering there are no other systemic symptoms. The patient should

undergo magnetic resonance imaging (MRI) to characterize the mass further, with neurol-

ogy/neurosurgery referral for outpatient follow-up (Figure 90.3).

Compressed

optic chiasm

Figure 90.3 T1-weighted gadolinium-

enhanced coronal MRI image demonstrating

an enhancing pituitary mass lesion with

suprasellar extension. The arrow highlights the

compression of the optic chiasm. This requires

urgent surgical attention so as to preserve

vision.

266

This patient has a pituitary adenoma, which is a slow growing tumour of the anterior

pituitary gland. Despite being benign, patients are frequently symptomatic depending on

its size and functioning status. Pituitary adenomas are classified into macro- or microad-

enomas. Patients with pituitary microadenomas (<10 mm) often present with symptoms

of hormonal imbalance resulting from functionally active tumours, most commonly pro-

lactin secreting with symptoms of amenorrhoea and infertility; instability of the adreno-

cortical, somatostatin and gonadotrophin axis can also occur.

In this case, the patient has a pituitary macroadenoma (>10 mm) with symptoms result-

ing from mass effect related to tumour bulk. Compression of normal pituitary tissue by

tumour has resulted in loss of TSH secretion and a clinically hypothyroid patient. In

addition, suprasellar tumour extension is causing compression of the optic chiasm and

stretching of the prechiasmic optic nerve. This is highlighted on the MRI study and is the

cause of the bitemporal hemianopia. With no intervention, the tumour will continue to

grow and he will be at risk of visual loss, obstructive hydrocephalus and carotid artery

involvement. This patient was referred to neurosurgery with successful tumour removal

and complete symptom resolution.

KEY POINTS

• The suprasellar space should be a review area when viewing unenhanced CT images.

• The use of intravenous contrast improves diagnostic interpretation.

• Always looks for optic chiasm compression in suprasellar masses.

267

CASE 91: A CLAUDICANT WITH WORSENING LEG PAIN

History

A 71-year-old man is referred to the vascular surgical team with right leg pain. He is

known to suffer from atherosclerotic peripheral vascular disease and is currently being

treated conservatively for claudication. The pain in his right leg started suddenly 3 hours

previously, with an achy discomfort that is not relieved by simple analgesia or position-

ing. Limited by pain, his mobility has reduced to only a few steps, and he reports increas-

ing discoloration of his right foot compared to the left.

His relevant medical history includes type 2 diabetes mellitus, hypertension and angina.

He is an ex-smoker of 40 pack-years. His drug history includes aspirin, metformin, iso-

sorbide mononitrate and a calcium channel blocker. He takes sublingual glyceryl trini-

trate as required.

Examination

Having been treated by the accident and emergency department for his pain, examina-

tion reveals a mottled right foot and reduced popliteal and pedal pulses compared to

the left side. Femoral pulses are symmetrical and strong bilaterally, with no evidence of

an expansile pulsatile abdominal mass. A computed tomography (CT) angiogram is per-

formed which suggests a right common femoral stenosis, and the interventional radiolo-

gists are approached for advice (Figure 91.1).

Figure 91.1 Lower limb angiogram.

Questions

• What type of study is this and what does it show?

• What treatment options are available in this case?

• What factors need to be considered when using radiographic contrast agents?

269

ANSWER 91

Figure 91.1 is a single view acquired during an angiogram of the lower limbs. It is a

procedure performed by the interventional radiologists on a fluoroscopy table, with the

patient in the supine position. With a sterile technique, a needle is passed into the com-

mon femoral artery (CFA) under ultrasound guidance and subcutaneous local anaesthetic

cover. In this case, a retrograde puncture of the left side was made to image the arteries

of both legs, however an antegrade puncture technique is sometimes preferable in cer-

tain situations. Adopting the Seldinger technique, a guidewire is passed via the puncture

needle into the aorta, and this is used to railroad a sheath and ‘pigtail’ multihole catheter.

Positioning the catheter at the aortic bifurcation, 15 mL of contrast is pumped at 8 mL/s

with digital subtraction images acquired of the opacified lower limb arteries.

A short tight stenosis of the mid superficial femoral artery on the right side is demon-

strated, with the artery narrowed by approximately 80 per cent by a flow-limiting athero-

sclerotic plaque. There is a paucity of collateral vessels suggesting an acute obstruction.

There is good run-off of the distal vessels. Both superficial femoral arteries demonstrate

a background of mild atherosclerotic calcification.

Although surgery in the form of endarterectomy or bypass could relieve this stenosis, an

open operation would carry significant risk and leave the patient with a visible scar. An

endovascular repair through the left CFA puncture is preferable, leaving the patient with

only a small pinhole scar in the groin and conserving the tissues of the right leg.

Crossing the aortic bifurcation, the stenosis can be transgressed with an atraumatic

hydrophilic guidewire. This can then guide the passage of a balloon-mounted bare

metal stent to the level of the stenosis. Balloon inflation (Figure 91.2) compresses the

atherosclerotic plaque and delivers the stent to exert radial force and maintain continued

patency long term (Figure 91.3).

The post-procedure angiogram (Figure 91.4) reveals a good response to treatment with

improved blood flow to aid symptomatic relief. The sheath and catheter are removed and

haemostasis of the groin achieved by manual compression. The patient will require dual

antiplatelet therapy to aid stent patency.

Radiographic contrast media is used in all aspects of radiology to enhance tissue contrast

and improve diagnostic interpretation. Barium, water and air can all be used in certain

examinations (e.g. barium enema) but this is not suitable for intravenous usage in CT

and angiographic studies. Iodine, with its high atomic number, has strong photoelectric

X-ray absorption characteristics that make it ideal for use in intravenous contrast media.

Injecting a predefined volume and imaging at a specific time allows for tissue enhance-

ment characteristics to be determined and improves the contrast between soft tissues

(Figure 91.4).

Before referring a patient for a study that involves the use of iodinated contrast, certain

parameters need to be checked. There are documented allergies to contrast media, and

also potential crossover in sensitive atopic individuals with shellfish and certain fruits

(e.g. strawberries). Contrast media is predominantly renally excreted and patients require

a degree of endogenous renal function to clear the injected contrast load. Intravenous

contrast is also nephrotoxic and can precipitate renal failure in predisposed patients. It

is important, therefore, to check a patient’s renal function prior to imaging to alleviate

this potential risk. Adequate hydration before and after the use of intravenous contrast

media is also recommended.

270

CASE 92: NORMAL VARIANT ON A CHEST RADIOGRAPH

History

Following her second year of foundation training, a 26-year-old junior doctor has

decided to spend a year in Australia gaining further experience. Having successfully

gained sponsorship by the Northern Sydney Central Coast Health Authority, she has to

be certified medically fit by a recognized senior physician to comply with immigration

policy. This involves completing a medical questionnaire, satisfying a medical examina-

tion, completing a series of screening blood tests and having a normal chest radiograph

with no evidence of communicable disease.

She feels well and has no relevant past medical history. Other than being an occasional

smoker there is no significant findings at history or physical examination.

Examination

Her blood results are as follows: white cell count (WCC) 9.4 × 10⁹/L, Na 137 mmol/L,

bilirubin 9 μmol/L, haemoglobin 11.6 g/dL, K 4.2 mmol/L, alanine aminotransferase (ALT)

27 IU/L, mean corpuscular volume (MCV) 78 fL, urea 4.1 mmol/L, alkaline phosphatase

146 IU/L, HIV negative, creatinine 87 μmol/L, albumin 41 g/L. Chest radiograph is shown

in Figure 92.1.

Figure 92.1 Chest radiograph.

Questions

• What normal variant is found on this chest radiograph?

273

ANSWER 92

Figure 92.1 is a chest radiograph of an adult female patient. It is not rotated and there

is adequate penetration with optimal inspiratory effort made. The heart is of normal

orientation and size (cardiothoracic ratio 30/12 cm), with both hilar correctly positioned

with normal appearances. Cardiomediastinal assessment demonstrates a right-sided aor-

tic arch. The lungs are clear and free from active disease. There is no evidence of old

Mycobacterium tuberculosis exposure. Bone review is normal. There is no pneumothorax

or evidence of free air under the diaphragm.

Normal aortic anatomy: The aorta is divided into the ascending thoracic aorta, arch of

the aorta, descending thoracic aorta and abdominal aorta. The ascending aorta begins at

the aortic root running superiorly and anteriorly, adjacent to the right side of the ster-

num. It is enclosed with the pulmonary trunk in a sheath of serous pericardium and is in

continuation with the arch of the aorta. Lying behind the manubrium of the sternum, the

aortic arch runs superiorly, posteriorly and from left to right anterior to the trachea. The

arch gives rise to the brachiocephalic artery, left carotid artery and left subclavian artery

as it runs across the mediastinum to become the descending thoracic aorta. This descends

inferiorly as a posterior mediastinal structure, piercing the diaphragm at the level of the

twelfth thoracic vertebra and is in continuity with the abdominal aorta.

A right aortic arch is an embryological variant with persistence of the right arch and right

descending aorta while undergoing regression of the left side. Seen in approximately 2 per

cent of the western population, its course within the chest is to the right of the trachea

and oesophagus, crossing the midline in the lower thorax to pierce the diaphragm in the

anatomically correct position. Its incidence increases in congenital heart disease (e.g. tetral-

ogy of Fallot), and is commonly associated with one of three aberrant vascular anomalies:

• Right aortic arch with aberrant left subclavian artery: This is the commonest right

aortic arch anomaly and is associated with cardiac septal defects and coarctation. The

patient is usually asymptomatic but its positioning predisposes to aortic torsion in

adulthood. The left carotid artery is the first branch of the aortic arch with an aberrant

left subclavian artery arising from the proximal descending aorta.

• Right aortic arch with mirror image branching: As the second commonest right aortic

arch anomaly, this is caused by embryological interruption of the arch between the left

subclavian artery and the descending aorta, most commonly just distal to the ductus arter-

iosus. The great vessels branch opposite to the anatomicial norm, and patients are often

symptomatic, being strongly associated with cyanotic heart disease (e.g. truncus arteriosus).

• Right aortic arch with isolated left subclavian artery: In this third most common scen-

ario, the aortic arch is interrupted between the left common carotid artery and the left

subclavian artery. The result is a left subclavian artery arising from the left pulmonary

artery, and the patient is symptomatic with congenital subclavian steal syndrome.

A right aortic arch is a normal anatomical variant. Having survived into adulthood with

no symptoms, it is highly unlikely that this incidental finding is of any clinical conse-

quence. The student was passed fit to travel, and had a successful year in Australia.

KEY POINTS

• The normal aortic arch runs superiorly, posteriorly and from left to right anterior to the

trachea.

• A right-sided aortic arch is seen in 2 per cent of the population.

• There are often concomitant aberrant vascular anomalies with a right-sided aortic arch.

274

CASE 93: FLANK PAIN AND HAEMATURIA

History

An intravenous urogram (IVU) study is requested on a 41-year-old man who has pre-

sented with right flank pain. His symptoms started 3 days ago with a dull pain on his

right side just below his ribs, which has remained constant and is not relieved by simple

analgesia. He attended his local accident and emergency department last night as the pain

woke him from sleep, and a presumptive diagnosis of a right-sided renal stone was made.

He was placed on appropriate analgesia.

He had no relevant medical history until last year when he experienced an acute but

short-lived pain on his left side while on holiday in Africa. Returning to the United

Kingdom, his general practitioner (GP) retrospectively diagnosed a renal stone and inves-

tigations showed a slightly elevated serum calcium and parathyroid hormone level. He is

currently being investigated for hypercalcaemia and further nuclear medicine studies are

scheduled next month.

Examination

His results today demonstrate a deterioration in renal function (creatinine 320 μmol/L)

compared to a normal baseline last month. His urine dipstick is positive for microscopic

blood but free from white cells and protein. On examination he is more comfortable fol-

lowing analgesia, but there is a pain on deep palpation and a fullness to the right side of

his abdomen compared to the left. The intravenous urograms are shown in Figure 93.1.

(a)

(b)

Figure 93.1 Intravenous urograms: (a) control; (b) 20 minutes post contrast.

Questions

• What does this IVU study demonstrate?

• What imaging modalities are available to characterize this type of problem?

• How should this patient be treated?

275

ANSWER 93

These are two images from an IVU study. The control film (Figure 93.1a) demonstrates a

solitary well-defined calcified focus measuring 12 mm overlying the right pelvico-ureteric

junction (PUJ)/upper ureter. There is no other radio-opacity overlying the renal tracts and

both kidneys appear of equal size and shape. Post intravenous contrast administration

(Figure 93.1b) there is asymmetrical excretion of contrast, with normal appearances to the

left kidney and ureter, but delayed excretion and a persistent nephrogram on the right.

No contrast is seen within the right collecting system on the post-micturition 20-minute

film, suggesting a partially obstructed right renal system.

On delayed imaging at 4 hours (Figure 93.2), there is excretion of contrast into a dilated

pelvicocalyceal system, with the distal pelvis measuring approximately 11 mm. There is a

faint trace of contrast seen within the right mid ureter, with additional contrast collect-

ing in the bladder compared to the 20-minute post-micturition film. These findings are

in keeping with a partially obstructed right renal system, most likely caused by a renal

stone at the PUJ/proximal ureter.

Figure 93.2 Delayed imaging at 4 hours.

Nephrolithiasis is the most common cause of renal calcification with over 10 per cent of

the western population developing a stone by the age of 70 years.¹ The majority of renal

stones (80 per cent) are made of calcium oxalate/calcium phosphate and are commonly

associated with primary and secondary hypercalcaemia. The remaining renal stones have

a mineral composition of either cystine or magnesium ammonium phosphate (struvite).

Rarely, renal stones can be formed from either uric acid, xanthine or a mucopolysaccaride

matrix, and it is important to remember this, as these stones are radiolucent and therefore

radiologically invisible.

276

Other than an IVU, other imaging modalities include:

• Ultrasound: The renal stone is highly echogenic against the grey renal parenchyma,

with an acoustic shadow often projected deep to the stone. Ultrasound also carries a

high sensitivity of detecting pelvicocalyceal dilatation and does not expose the patient

to ionizing radiation. Its limiting factor is operator dependence. Small, non-obstruct-

ing stones may be poorly visualized due to renal pelvis fat, which is also echogenic.

• Computed tomography (CT): Non-contrast CT-KUB (kidneys, ureter, bladder) is the

gold standard and is highly sensitive for renal stone detection and characterization.

The radiation dose is low and exam time is short (less than 5 minutes), with no risk of

nephropathy as intravenous contrast is not required. Stone size, position and density

can be assessed to guide treatment (e.g. lithotripsy or percutaneous nephrolithotomy

(PCNL)). CT-KUB is replacing IVU as the preferred imaging modality for renal stone

disease.

• Nuclear medicine: There is a limited role for both MAG3 and DTPA (diethylene tri-

amine pentaacetic acid) studies in cases of nephrolithiasis, with the stone appearing

as an area of photopenia on a background of homogeneous uptake. In an obstructed

system the studies are more useful and can demonstrate renal perfusion abnormalities

and can be used to compare the split function of both kidneys.

• Magnetic resonance imaging (MRI): This modality has no significant role in the diag-

nosis of renal stone disease but may do in the future.

In this patient, an obstructed right renal system and deteriorating renal function needs

to have definitive treatment to decompress the renal pelvis and preserve right kidney

function. Options include a percutaneous nephrostomy inserted under fluoroscopy guid-

ance by the interventional radiologists (see Case 71). However, the nephrostomy drainage

catheter can only remain in place for a limited time and this procedure carries risks of

infection and bleeding. The preferred alternative is a ureteric stent which can be placed

in a retrograde fashion during cystoscopy over a guidewire. The ‘double-J’ stents have

multiple perforations and can bypass the stone, allowing pelvicocalyceal decompression.

The ureteric stent can remain in place for up to 3 months while a definitive decision on

stone removal is made, and is then easily removed during a repeat cystoscopy procedure

when necessary (Figure 93.3).

Figure 93.3 Ureteric stent in place.

277

CASE 94: PATIENT WITH AN INTRACTABLE HEADACHE

History

A 42-year-old woman is bought to the accident and emergency department by her

husband complaining of headache. Her symptoms started a few hours earlier with the

sudden onset of sharp stabbing pain at the back of her head. This rapidly progressed and

soon became the worst headache she had ever had. Despite simple analgesia and rest, the

headache did not subside and the pain caused her to vomit several times. There has been

no altered consciousness but her husband was concerned by her restlessness and agita-

tion, and brought her to hospital.

The patient has a past medical history of asthma, which is well controlled on inhalers

provided by her general practitioner (GP). She also has annual review with the hospital

nephrologists for a history of polycystic kidney disease.

Examination

She is irritable and looks unwell. She is hypertensive (170/110) and has a regular pulse of

105 beats per minute. There is neck stiffness, and worsening of her headache on straight

leg raising but no focal neurology. Ophthalmoscopy is not tolerated and the patient asks

you to turn the lights off as they are hurting her eyes. A computed tomography (CT) scan

was performed (Figure 94.1).

Figure 94.1 Unenhanced axial CT scan.

Questions

• What does the CT scan demonstrate?

• Why was this patient at increased risk?

• What would you do if the CT scan had been normal?

279

ANSWER 94

This image is a single slice from an unenhanced CT scan taken at the level of the basal

ganglia. There is widespread abnormal high attenuation with a gyriform distribution

within both cerebral hemispheres. This high attenuation material is denser than adjacent

brain parenchyma but less dense than bone and represents acute blood. In the image,

arrows demonstrate acute blood replacing CSF within the Sylvian fissure (white arrow)

and quadrigeminal cistern (black arrow). There is mass effect with sulcal effacement

and the lateral/third ventricles are prominent in keeping with hydrocephalus. Some

acute blood is seen within the third ventricle at the expected origin of the aqueduct of

Sylvius. This patient has therefore suffered an acute subarachnoid haemorrhage (SAH)

with hydrocephalus.

Subarachnoid haemorrhage is defined as blood collected between the pia and arachnoid

mater. Clinically, patients with an SAH commonly present with an acute severe occipital

headache (‘thunderclap’) with associated vomiting, altered conscious state and agitation.

Unenhanced cranial CT demonstrates acute blood (white - HU 60-70) within the cerebro-

spinal fluid (CSF) spaces. Large haemorrhages can be easily seen, but smaller bleeds can

be more difficult.

Causes of SAH include:

• ruptured aneurysm,

• AV malformation,

• hypertensive haemorrhage,

• haemorrhage from tumour,

• intracranial infection,

• blood dyscrasias, and

• anticoagulation.

Adult polycystic kidney disease (APKD) is an autosomal dominant genetic condition,

which is slow to progress but has 100 per cent penetration in the affected individual.

Multiple thin-walled cysts form within native kidneys. Commonly causing pain, haema-

turia and proteinuria, unrestricted cyst growth replaces normal renal parenchyma, even-

tually causing renal failure. The patient is also at increased risk of developing renal cell

carcinoma. APKD has associations with cysts in other organs (e.g. liver and pancreas),

mitral valve prolapse and saccular ‘berry’ aneurysms of the cerebral arteries (3-13 per

cent).¹ These aneurysms tend to be multifocal and rupture of any aneurysm causes blood

to leak into the subarachnoid space and SAH.

If the CT scan in a patient with this suspicious history had been normal, a lumbar punc-

ture would need to be considered as a normal cranial CT does not exclude small SAH

(sensitivity 90 per cent).¹ Lumbar puncture is essential to confirm the presence of normal

or altered blood (xanthochromia) within the circulating CSF that bathes the brain. Any

blood in the CSF space can cause obstruction and put the patient at risk of communi-

cating/non-communicating hydrocephalus and death. Clinicians often feel reassured by

requesting a cranial CT to exclude the absolute contraindication of raised intracranial

pressure (ICP) before lumbar puncture to reduce the risk of ‘coning.’ However, cranial CT

is not a sensitive exclusion modality,² and full clinical assessment looking for the stig-

mata of raised ICP would be advised.

280

CASE 95: AN UNWELL PATIENT WITH A RASH

History

You are asked to see a 32-year-old Afro-Caribbean man who complains of feeling gener-

ally unwell for the last week. He has had a low-grade fever that has not resolved despite

bed rest and anti-pyrexial medication. He denies having a cough or any urinary symp-

toms and is usually a fit and active person. Over the last 2 days he has noticed a red rash

on his legs that is becoming increasingly hot and tender, and also complains of facial

swelling with an achy discomfort in his jaw. He has also had to stop wearing his contact

lenses as his eyes have become red and irritable.

Examination

On examination he looks tired with red conjunctiva and a temperature of 38.1°C. There

is smooth swelling of the parotids bilaterally with tenderness on palpation. His cardio-

vascular, respiratory and abdominal examination is normal but there is an ill-defined

rash on the anterior aspect of both his shins that is raised, nodular and tender.

A full septic screen is performed and while the blood results are awaited, a chest radio-

graph is performed (Figure 95.1).

Figure 95.1 Chest radiograph.

Questions

• What does the chest radiograph demonstrate?

• How could a diagnosis be confirmed?

• What are the extrathoracic manifestations of this disease?

283

ANSWER 95

This is a posterior-anterior (PA) chest radiograph of an adult male patient, which has

adequate inspiration, penetration and is not rotated. There is bilateral hilar enlarge-

ment with widening of the paratracheal stripe and loss of the normal convexity to the

aortopulmonary window. These features are in keeping with lymph node enlargement

and suggest the ‘1-2-3 sign’ of Garland’s triad. The lung parenchyma also demonstrates

pathology, with reticular nodular shadowing bilaterally in a mid and upper zone distri-

bution with basal sparing. The nodules are small (<2 mm) and there is no evidence of

cavitation, pneumothorax or pleural effusion. The heart is of normal size and bone review

is unremarkable.

Taking account of the ethnicity, history and examination of this patient, the top differen-

tial for these appearances would be acute sarcoidosis (Lofgren’s syndrome). In the absence

of an infective cause, biochemical and radiological findings are helpful, although defini-

tive diagnosis relies on obtaining tissue by procedures such as transbronchial biopsy at

bronchoscopy. The following should be noted:

• serum levels of angiotensin-converting enzyme (ACE) can be elevated in normal indi-

viduals;

• on chest radiograph, as well as the typical features described above, a more chronic

picture can demonstrate parenchmyal volume loss and fibrosis, pleural effusions and

mediastinal/hilar ‘egg-shell’ calcification;

• high-resolution computed tomography (HRCT) may be useful (Figure 95.2).

Figure 95.2 HRCT scan.

Although bilateral hilar adenopathy is the hallmark of this disease, the lung parenchyma

is involved in approximately two-thirds of cases. High-resolution (thin, 1 mm) slices

confirm reticular shadowing related to thickening of the interlobular septae from the

interstitial lung disease. However, the presence and distribution of additional nodules is

key to the diagnosis. The nodules can vary in size (2-4 cm) and are caused by lymphoid

hyperplasia related to the granulomatous response. Histologically, therefore, the nodules

have a peri-lymphatic distribution and follow the course of the arterioles and bronchi-

oles and are termed ‘bronchovascular’ in distribution. The nodules are most conspicuous

284

along the thickened lung fissures, and give a ‘beaded’ appearance, which is demonstrated

in Figure 95.2 particularly along the oblique fissure of the left lung. HRCT features in

chronic disease can demonstrate fibrosis and loss of lung volume causing dilatation of

the distal airways. This is termed ‘traction bronchiectasis’.

Sarcoidosis is a multisystem granulomatous disease of unknown aetiology, and although

thoracic manifestation is the commonest presentation, other organs are affected as

follows:

• Skin: Cutaneous plaques, nodules and scarring can occur and are collectively termed

‘lupus pernio’. More acutely, the patient can suffer from erythema nodosum where the

skin is red and hot with tender nodularity.

• Gastrointestinal: Plaques and nodular granulomas can cause mucosal fold thickening

anywhere along the gastrointestinal tract. This is most commonly seen in the stomach,

followed by the colon, oesophagus and small bowel. Chronic involvement results in

stricture formation with luminal narrowing.

• Hepatobiliary: Upper abdominal viscera involvement primarily causes organomegally.

Late in the disease, granuloma formation can cause hepatic nodularity, however the

patients often remain asymptomatic.

• Bone: Osseous involvement is a radiologist’s favourite, most commonly affecting the

hands and feet. Granuloma formation within the bone medulla causes loss of normal

trabeculation resulting in a characteristic reticular ‘lace-like’ appearance. The overly-

ing cortex demonstrates periosteal reaction and subperiosteal resorption mimicking

hyperparathyroid disease.

• Neurological: Although a rare entity of the disease, cranial nerve palsies are the com-

monest manifestation (e.g. bilateral VIIth) with cerebral granuloma formation infre-

quently presenting as a space-occupying lesion.

KEY POINTS

• The presence of Garland’s triad on a chest radiograph is highly suggestive of thoracic

sarcoidosis.

• Lung nodules demonstrate a bronchovascular distribution on HRCT.

• As a multisystem granulomatous disease, sarcoidosis can affect any organ in the body.

285

CASE 96: CHEST WALL SWELLING AND A PLEURAL EFFUSION

History

A 58-year-old woman with a history of lung cancer has had a chest drain inserted for

resolution of a unilateral right-sided pleural effusion. Since its insertion, the patient has

noticed that the skin at the insertion site is continuing to slowly swell. This is exacer-

bated on coughing. She denies any shortness of breath or pain, and there is no evidence

of active haemorrhage.

Examination

Examination reveals an ill-defined fullness to the right lateral chest wall, which has

increased in size over the last few days. It is soft and compressible with nodularity felt

on light palpation. The clinicians are concerned about basal crepitations over the area

on auscultation with no evidence of a vascular bruit. The patient’s blood results are

unchanged from admission and a chest radiograph has been taken to assess positioning

of the chest drain (Figure 96.1).

Figure 96.1 Chest radiograph.

Questions

• What does this chest radiograph demonstrate?

• What are the common causes of this finding?

• How should the patient be treated for this condition?

287

ANSWER 96

Figure 96.1 is an anterior-posterior (AP) semi-erect chest radiograph of an adult female

patient. It is adequately penetrated with slight rotation. There is an intercostal chest drain

within the right hemithorax with its tip positioned at the right apex. There is a small

right-sided pleural effusion but no evidence of pneumothorax. The lungs are clear of any

consolidation or collapse and the cardiomediastinal boarders are within normal limits.

The soft tissues of the right lateral chest wall are expanded at the site of the chest drain

insertion with locules of low-density gas projected within a subcutaneous distribution.

These are confined to the right side with no cranial extension. These features are consist-

ent with surgical emphysema of the right chest wall.

Surgical emphysema (also referred to as subcutaneous emphysema) occurs when gas col-

lects within the subcutaneous tissues. It is able to track freely along the fascial planes,

separating the tissue layers and causing distension. This is an enormous potential space

and gas follows the path of least resistance limited only by the integrity of the overlying

skin. Without correction of the underlying insult, the patient can become very swollen in

appearance (Figure 96.2), with clinical examination revealing a unique ‘crackling’ sound

akin to having crumpled tissue paper under the skin. Separation of the tissue planes

is painless, with mild discomfort caused by increased skin tension and their bloated

appearance.

Figure 96.2 Chest radiograph showing

swollen appearance.

Causes include:

• Infection: In susceptible patients (e.g. people with diabetes) the presence of a gas-

forming organism under the skin will produce subcutaneous emphysema. When asso-

ciated with tissue death, this gas gangrene requires surgical debridement to clear the

organism, most commonly Clostridium perfringens.

• Trauma: Any form of blunt or penetrating trauma that disrupts the parietal covering

of an air-containing organ (e.g. lung or intestinal tract) will form a conduit for air

to move into the subcutaneous tissues along a favourable pressure gradient. This is

most commonly seen in pneumothoraces associated with rib fractures or stabbings

where a shard of bone or the knife pierces the parietal pleura. During expiration, air is

forced into the subcutaneous space. Similarly, Boerhaave’s syndrome with a ruptured

288

oesophagus will cause a pneumomediastinum and air can track into the subcutaneous

tissues of the neck.

• Spontaneous: Patients with chronic lung disease (e.g. asthma, chronic obstructive

pulmonary disease (COPD), cystic fibrosis) can suffer a spontaneous pneumothorax. If

associated with disruption of the visceral pleura, air will track via the mediastinum to

the subcutaneous space. This is also seen in intubated patients with barotraumas from

ventilation pressures.

• Iatrogenic: The commonest cause of subcutaneous emphysema is following medical

intervention or surgery. In the case described, the chest drain inserted for drainage

of a pleural effusion has formed a conduit with the subcutaneous space. Air from a

subclinical pneumothorax is leaking around the drain at the intercostal space and

accumulating in the adjacent tissue. This drain is appropriately sited, however a fenes-

trated chest drain that is incorrectly placed with some of the drain holes outside the

chest cavity will also cause subcutaneous emphysema. This is an important review

area when reporting chest radiographs following drain insertion.

Having removed the original insult, the treatment for surgical emphysema is conserva-

tive. Air within the subcutaneous tissues will be slowly reabsorbed over a few weeks with

no repercussions, but correction of the causative agent (e.g. pneumothorax) is essential

to prevent reaccumulation.

KEY POINTS

• Surgical emphysema occurs when gas accumulates within the subcutaneous tissues.

• Tracking along fascial planes, patients can become enormously distended and

uncomfortable.

• When placing a fenestrated chest drain, ensure all drain holes lie within the chest

cavity to avoid surgical emphysema.

289

CASE 97: CHEST WALL DEFORMITY IN A PACEMAKER PATIENT

History

You are asked by a junior doctor to review the chest radiograph of an 80-year-old man

electively admitted for a pacemaker box change. Previously treated at another institution,

there are no radiographs available for comparison. The patient is medically well and does

not give a history of recent trauma. His past medical history includes previous syncope

related to heart block, and he recalls a series of operations in his 20s for the treatment

of tuberculosis.

Examination

On examination the patient is comfortable at rest with normal observations. Inspection

reveals a right chest wall deformity and signs consistent with previous surgery. There is

reduced lung expansion on the right, with reduced air entry at the apex and an area that

is dull to percussion compared to the contralateral side. A chest radiograph is performed

as part of the admission process (Figure 97.1).

Figure 97.1 Chest radiograph.

Questions

• What does the chest radiograph demonstrate?

• What is this procedure and why was it performed?

• What other methods of treating this disease were employed before drug therapy?

291

ANSWER 97

Figure 97.1 is a frontal chest radiograph of an adult male patient, which is of adequate

penetration but is rotated to the left. There is thoracic asymmetry, with a right-sided chest

wall deformity centred on the upper zone. There has been surgical removal of the first

five ribs on the right and corresponding transverse processes of the spine, with normal

appearances of the ipsilateral clavicle and scapula. The right lung apex demonstrates

volume loss from medialization and compression of the adjacent chest wall. There is no

pleural effusion or pneumothorax and the changes appear chronic. Of note, there is a

dual wire cardiac pacing device and the left hemithorax has normal appearances. These

findings are characteristic of previous thoracoplasty for the treatment of pulmonary

tuberculosis.

Mycobacterium tuberculosis was first described by Robert Koch in 1882. As an aerobic

bacteria, it has an affinity for the lung apices where there is a higher ventilation perfusion

ratio. The treatment for tuberculosis has radically changed over the last 100 years to the

current 6-month regime starting with four drugs. Before the introduction of drug therapy,

several methods of ‘collapse therapy’ existed, all with the common aim of reducing venti-

lation in the affected area. Thoracoplasty was practised until the 1960s, and an estimated

30000 procedures were performed in the UK between 1951 and 1960.¹ Clinicians should

be aware of the characteristic chest appearances, as it is still practised today in developing

countries where the cost of chemotherapy is deemed excessive, and has been proposed in

extensively resistant disease. In India, 139 thoracoplasties were performed between 1992

and 1997.² Cor pulmonale may result from the restrictive lung defect, particularly if the

residual lung is affected by chronic obstructive pulmonary disease (COPD).

Thoracoplasty is commonly a three-stage procedure, with the ‘modern’ technique, as

described in 1949, involving the eventual removal of the first to seventh ribs with their

transverse processes and the angle of the scapula.³ The superior lateral chest wall is then

compressed towards the mediastinum, collapsing the affected upper lobe. Dewan et al.

document a 66 per cent success rate in modern-day practice.²

Although thoracoplasty was widely used, other causes of ‘collapse therapy’ include the

following:

• Pneumothorax: Forcibly introducing air into the pleural cavity, causing iatrogenic

collapse of the lung, was deemed in 1820 a ‘ray of sunshine in the dark history of

tuberculosis’.⁴ As the air was reabsorbed, frequent repeat procedures were necessary.

Pneumoperitoneum was used for disease at the lung bases.

• Internal pneumolysis: Visceral/parietal adhesions were internally cauterized under

direct vision with a thoracoscope before forcible pneumothorax collapse.

• Oleothorax: It was thought that the use of antiseptic mineral or vegetable oil instead

of air for forcible lung compression reduced the risk of tuberculous empyema and the

need for repeat procedure.

• Phrenic nerve crush: Paralysing the ipsilateral hemidiaphragm to the tuberculous

foci reduced oxygenation. Success was seen in lower lobe granulomas when used in

combination with pneumothorax techniques.

• Plombage: For patients unsuitable for external thoracoplasty compression or with

bilateral disease, a combination of inert paraffin and bismuth was injected into

the pleural cavity, forcibly compressing the adjacent lung. The use of inert Lucite

(poly(methyl methacrylate)) balls was a later development but had characteristic

appearances (Figure 97.2).

292

Figure 97.2 Appearance of Lucite balls on chest

radiograph. Reproduced from Life in the Fast Lane medical

blog, www.lifeinthefastlane.com, with permission.

KEY POINTS

• Thoracoplasty for the treatment of Mycobacterium tuberculosis infection is still

practised in developing countries.

• First to seventh ribs are often surgically removed with compression of the superior

lateral chest wall.

• Before chemotherapy, ‘collapse therapy’ was deemed a ‘ray of sunshine in the history

of tuberculosis’.

References

1. Phillips, M.S., Kinnear, W.J.M. and Shneerson, J.M.

(1987) Late sequelae of pulmonary

tuberculosis treated by thoracoplasty. Thorax 42: 445-51.

2. Dewan, R.K., Singh, S., Kumar, A. and Meena, B.K. (1999) Thoracoplasty: an obsolete procedure?

Indian Journal of Chest Diseases and Allied Sciences 41(2): 83-88.

3. Broenrigg, G.M. (1949) Thoracoplasty for pulmonary tuberculosis. Canadian Medical Association

Journal 61: 601-602.

4. Singer, J.J. (1936) Collapse therapy in tuberculosis. California and Western Medicine 45(2):

120-25.

293

CASE 98: SUDDEN ONSET BACK PAIN IN A 72-YEAR-OLD WOMAN

History

A 72-year-old woman is referred by her general practitioner (GP). She complains of sud-

den onset of back pain while playing with her grandchild 6 weeks ago and although her

pain is now much better with analgesia, her symptoms have not resolved completely. She

denies any history of direct trauma. Her pain is aching in character centred on her tho-

racic spine with stabbing exacerbations on certain movements, limiting her mobility. She

does not complain of any numbness, tingling or pins and needles. She is able to walk and

move all four limbs independently with no complaints of bowel or bladder disturbance.

She has had no weight loss, change in bowel habit or any stigmata of infection.

Her past medical history includes bowel cancer 3 years ago treated with a right hemi-

colectomy. She has had no problems since.

Examination

She had a computed tomography (CT) scan performed 1 week ago as part of her contin-

ued surveillance. This did not report any evidence of local recurrence but did reveal an

abnormality on bone review (Figure 98.1).

Figure 98.1 CT scan.

Questions

• What does this image demonstrate and what type of image is it?

• What is a bone scan?

• What is the likely cause of this patient’s problems?

295

ANSWER 98

The image displayed in Figure 98.1 is a maximal intensity projection (MIP) of the lower

thoracic, lumbar and sacral spine, reconstructed in the sagittal plane. MIPs are a type

of post-processing technique regularly used in CT, and although MIP physics are out of

the remit of this answer, they allow for both 2- and 3-dimensional reconstruction for

improved diagnostic interpretation.

The image has been windowed to improve bony resolution. There has been collapse and

loss of height of T12 in its anterior aspect with relative preservation of the vertebral body

posteriorly in keeping with a wedge compression fracture. There is resultant kyphosis.

Coronal imaging (Figure 98.2) confirms uniform loss of vertebral body height anteriorly,

which is accentuated more on the right than the left.

Figure 98.2 Coronal image.

There are many causes of vertebral body collapse, with the most common being trauma,

malignancy and osteoporosis. Patients often complain of associated back pain and can

have neurological symptoms if there is bony encroachment of the adjacent spinal canal

with either cord or nerve compromise. The shape of the vertebral collapse can also be

seen to change the normal curvature of the thoracic spine, and in elderly people suffering

multilevel osteoporotic fractures, this can cause an overall loss of vertical height and a

severe kyphoscoliosis.

It is important to establish a cause for the vertebral collapse, so that steps can be taken to

prevent deterioration, multilevel involvement and a potential neurological deficit. Having

excluded a history of trauma, the main differential lies between loss of vertebral bone

integrity related to either malignancy or osteoporosis. Although it is impossible to say

with certainty that a vertebral collapse on CT is due to osteoporosis rather than malig-

nancy, other radiological studies can be employed to help distinguish between them. A

bone scan can be very helpful and is discussed below, with a magnetic resonance imaging

(MRI) scan often performed not only to diagnose any evidence of neurological compro-

mise, but to define characteristic features of acute vertebral collapse that can infer one

cause rather than the other. The infiltrative process of malignancy often causes diffuse

loss of normal bone marrow signalling on T1 imaging and post-gadolinium; abnormal

enhancement may be demonstrated with or without an associated epidural soft tissue

296

mass. As some fatty marrow is maintained in osteoporosis, associated vertebral collapse

often retains its concave posterior wall and is more likely solitary, as multilevel involve-

ment is more in keeping with malignancy.

A bone scan (also referred to as ‘bone scintigraphy’) is a common type of nuclear medi-

cine study that utilizes the normal physiological response to any bony insult, whether

it be malignant, infective or osteoporotic. The radiotracer technetium-99m is chemically

attached to methylene-diphosphate (MDP), and is preferentially taken up by osteoblasts

when intravenously injected into the body and incorporated into the matrix of healing

bone via hydroxyapatite deposition. Decay of this radioactive isotope is recorded on

a gamma camera and generates a skeletal image of normal physiological uptake with

‘hot-spots’ of radioisotope accumulation at sites of bony injury. Interpretation of the

distribution of tracer uptake can both imply an aetiology and also reveal other sites of

abnormality that were previously clinically invisible.

In the bone scan of the same patient, there is a focal region of increased tracer uptake to

the right of T12 and to the left of the lower lumbar vertebrae (Figure 98.3). Mild tracer

uptake is also noted at the shoulders, knees, ankles and feet. The appearances are sug-

gestive of vertebral degenerative collapse related to osteoporosis in keeping with the

given CT images, however a solitary metastasis cannot be excluded. Tracer uptake in the

joints is suggestive of further degenerative disease. Multiple ‘hot-spots’ suggest skeletal

metastases have not been demonstrated.

Figure 98.3 Bone scan.

KEY POINTS

• CT scans have a high sensitivity at resolving bony pathology.

• If there is clinical suspicion of spinal cord involvement then an MRI study needs to be

performed. MRI can help differentiate between osteoporosis and metastatic collapse.

• Bone scintigraphy can reveal sites of bony involvement that are clinically invisible.

297

CASE 99: CONSTIPATION AND COLICKY ABDOMINAL PAIN

History

A 78-year-old woman was transferred from the local nursing home complaining of

abdominal pain and vomiting. She has been suffering from intermittent colicky abdomi-

nal pain for several years with no clear exacerbating or relieving factors. The pain comes

on gradually, centred on the lower abdomen, and usually lasts a few hours before resolv-

ing spontaneously. It is often associated with nausea but never vomiting. She has been

extensively investigated with computed tomography (CT) and a colonoscopy, but these

were performed when the patient was asymptomatic and found no abnormality.

A typical episode started last night but the pain has failed to resolve by itself. She has not

passed any faeces or flatus for 12 hours and complains of abdominal distension. She has

a past medical history of hip replacements, diet-controlled diabetes and coronary artery

disease. She has a long history of constipation and has been on laxative treatment for the

last 20 years. She denies weight loss or recent change in bowel habit.

Examination

A plain abdominal radiograph was performed as part of the initial investigations (Figure

99.1).

Figure 99.1 Abdominal radiograph.

Questions

• What does this radiograph demonstrate?

• What is the diagnosis and is there a differential for these appearances?

• Can this affect other parts of the body?

299

ANSWER 99

Figure 99.1 is a plain abdominal radiograph of an elderly patient with a background of

degenerative bony change and bilateral hip replacements. There are dilated loops of large

bowel extending from the caecum round to the sigmoid colon with maximal bowel diam-

eter of 7 cm. The small bowel is decompressed and there is a paucity of gas within the

rectum. Centrally, there is an isolated loop of grossly dilated large bowel that assumes an

oval configuration centred on a linear density in the left lower quadrant. This is the char-

acteristic ‘coffee-bean’ sign of sigmoid volvulus. There is no evidence of intra-abdominal

free gas to suggest bowel perforation (Figure 99.2).

Black line around sigmoid volvulus

Indicates mesenteric axis

Figure 99.2 Abdominal radiograph indicating mesenteric axis and

volvulus.

Volvulus is defined as twisting of the intestinal tract around a mesenteric axis. It is

relatively rare but most commonly seen within the colon where it accounts for one in

ten causes of large bowel obstruction. The mid- and hindgut is associated with a fold of

fibro-fatty tissue called the mesentery, which provides mechanical support and carries

nerves, blood vessels and lymphatics to the bowel. Anchored to the back of the abdominal

wall, those loops of bowel that lie furthest from the mesenteric root are more mobile and

can be susceptible to rotation. In the large bowel, the caecum and sigmoid colon are the

300

commonest sites of involvement, with predisposing factors including an unusually long

mesentery or chronic constipation.

Rotating around a mesenteric axis, the bowel twists and closes the lumen, causing bowel

obstruction. This can resolve spontaneously in response to peristalsis, with patients com-

plaining of intermittent resolving abdominal pain. Failure to untwist the bowel will cause

bowel dilatation proximal to the obstruction with symptoms of pain, abdominal disten-

sion and vomiting. Patients may also have abdominal compartment syndrome because

of the mass effect from the dilated bowel loop. Blood vessels supplying the involved

segment of bowel are subject to strangulation, and this can lead to bowel ischaemia and

infarction. Without definitive treatment, this carries a high mortality.

Differentiating between caecal and sigmoid volvulus can be difficult on plain radiograph:

• Sigmoid is commonly seen in the elderly with plain film findings of an isolated

enlarged loop of large bowel centred on the left side with cranial extension towards

the diaphragm. A midline fold that represents the twisted mesenteric axis can be seen,

causing the characteristic ‘coffee-bean’ appearance (arrow). There is often associated

transverse and ascending colon dilatation, with normal small bowel calibre if the ileo-

caecal valve is competent.

• Caecal is a disease of the young (averaging 30 years) with the dilated caecum rotating

anteriorly and lying in the left upper quadrant. This is associated with small bowel

dilatation and puts the patient at increased risk of bowel perforation.

Other types of volvulus include the following:

• Gastric: Rotation of the stomach around the supportive gastrohepatic (lesser curve) or

gastrocolic (greater curve) mesenteries can cause sudden onset severe abdominal pain

and vomiting. It is considered a surgical emergency carrying up to 80 per cent mor-

tality if treatment is not initiated quickly. There are two types: organoaxial (rotating

in a vertical axis, imaging reveals the characteristic appearances of a ‘mirror-image’

stomach with the greater curve within the right upper quadrant) and mesenteroaxial

(rotating along a horizontal axis, the stomach appears to be upside down with the

pylorus seen at the expected gastro-oesophageal junction).

• Midgut volvulus (described in Case 88): This is associated with congenital malrota-

tion. Seen primarily in infants, the midgut rotates around the superior mesenteric

artery (SMA) axis, causing bowel obstruction and the characteristic ‘double-bubble’

sign on plain radiograph.

KEY POINTS

• Volvulus occurs when a loop of bowel twists around a mesenteric axis.

• Look for the characteristic ‘coffee-bean’ sign to help differentiate between a sigmoid

and caecal volvulus.

• Midgut volvulus is associated with congenital malrotation of the bowel.

301

CASE 100: AN ANKLE INJURY

History

A 27-year-old woman attends the accident and emergency department one morning

unable to weight-bear on her right ankle. She had been out two nights before and con-

sumed a large quantity of alcohol. She remembers falling, twisting her right ankle and

subsequently being unable to walk well. This had been painful over the course of the next

day and had kept her awake the previous night. She attended to check it was just a ‘sprain’.

Examination

She is unable to weight-bear on the right. Upon examination, the right ankle was swollen,

with reduced range of motion and there was bony tenderness upon bony palpation of the

lateral malleolus (distal fibula). She was neurovascularly intact distally, with foot pulses

and normal power/sensation in the foot. Radiographs were requested in the accident and

emergency department (Figure 100.1).

(a)

(b)

Figure 100.1 (a) Anterior-posterior (AP) and (b) lateral ankle radiographs.

Question

• What do the ankle radiographs demonstrate?

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ANSWER 100

The radiographs (Figure 100.1a,b) demonstrate an undisplaced spiral fracture of the distal

fibula (lateral malleolus) demonstrated with arrows on Figure 100.2.

Figure 100.2

Ankle fractures are usually the result of low-energy twisting/torsion forces and present

with swelling, deformity and inability to bear weight. Non-displaced ankle fractures may

occasionally exhibit minimal swelling and no deformity.

Ankle fractures are one of the most common fractures treated by accident and emer-

gency departments and comprise a range of different injury patterns, varying in severity.

Isolated malleolar fractures make up approximately two-thirds of ankle fractures, with

bimalleolar fractures occurring in a quarter, and trimalleolar fractures occurring in the

remaining 7 per cent of cases. Open fractures occur in approximately 2 per cent of cases.

The ankle is often thought of as a simple hinge joint, although biomechanically the axis

of rotation is constantly changing as the ankle allows variable degrees of rotation and

translation in the coronal and axial planes as well as the sagittal plane.

The ankle joint is formed by contributions from the tibia, fibula and talus. When the foot

is dorsiflexed, the widened anterior portion of the talus fits securely within the medial

and lateral malleoli and the talocrural joint acts as a true mortise with the bony structures

providing the majority of the stability. When the ankle moves into plantar flexion, the

304

narrower portion of the talar dome articulates between the medial and lateral malleoli,

where the talus does not fit as tightly (and the majority of the joint stability is conferred

by surrounding ligaments).

A number of methods of classification exist for ankle fractures, however it is most impor-

tant to simply describe the fracture, in particular whether the fracture is open or closed,

the condition of the soft tissue (including swelling or blisters) and the bony structures

involved (in particular, is it unimalleolar, bimalleolar or trimalleolar?). Further points may

include the fracture pattern, amount of comminution and the status of the syndesmosis.

More systematized methods include the commonly used Lauge-Hansen Classification and

Weber Classification:

• Lauge-Hansen Classification: This is based on the fracture pattern. Each configura-

tion is defined by two factors: the position of the foot (pronation or supination) and

the force applied to the ankle (adduction, external rotation or abduction). In addition

each configuration has a number of stages describing sequential injuries as the force

was applied, the most common mechanism being the supination-external rotation

pattern.

• Weber Classification: This is a simple system for classification of lateral malleolar

fractures relating to the level of the ankle joint and determining treatment. Fractures

are divided into three categories based on the level of the fibula fracture in relation

to the joint line (syndesmosis). Weber A fractures occur distal to the joint line, while

Weber B fractures involve the syndesmosis and Weber C fractures are confined above

the joint line. The fracture in this example would be an undisplaced Weber B fracture.

KEY POINTS

• Isolated malleolar fractures make up approximately two-thirds of ankle fractures.

• These injuries may only be seen clearly on one view of the ankle, therefore two views

are required in all cases of ankle trauma.

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INDEX

Note: Reference are the form of case number with page numbers in brackets. There are main entries for all imaging

modalities excluding ‘radiograph’ which occurs too frequently for indexing. There are though entries for the less-commonly

used terms involving X-rays such as ‘chest radiograph’, ‘contrast studies’, ‘fluoroscopy’ and ‘X-ray physics’.

abdomen

barium studies see contrast studies

distended

52(145-6)

Barton fracture

81(229-31)

abdominal weight gain and, despite dieting

85(245-8)

bicyclist in car accident, knee injury

31(97-8)

inability to pass flatus and

58(157-8)

biliary system abnormalities

6(15-16)

in ovarian cancer

69(187-9)

in Crohn’s disease

82(235-7)

premature neonate with

23(71-3)

obstruction

14(41-4)

shifting dullness and

55(151-2)

in sarcoidosis

95(283-5)

pain, acute

52(145-6)

biopsy, image-guided

14(41-4)

constipation and

99(299-301)

discitis

73(200-2)

diarrhoea and

80(225-8)

bladder, transitional cell carcinoma

71(193-6)

IUCD-related

49(139-40)

bleeding see haemorrhage

right upper

6(15-16)

bone

vomiting and see vomiting

fracture see fracture