VIQ - TEST PAPER 2

Question 1

@# 2.A 40-year-old man undergoes a CT scan of the abdomen for recurrent abdominal pain.
The precontrast scan showed bilateral renal calculi. A post-contrast scan showed severalpancreatic lesions, measuring between 1 and 2 cm. What is the likely unifying diagnosis?

A. MEN I

B. MEN IIA

C. Insulinoma

D. Glucagonoma

E. NF1

Answer 1

2.A. MEN 1

Multiple endocrine neoplasia Type 1 is also known as Wermer syndrome. Inheritance isautosomal dominant with high penetrance. The male to-female ratio is 1:1. Organ involvement includes parathyroid hyperplasia (97%), pancreatic islet cell tumour (30% 80%), anterior pituitary gland tumour (15%—50%) and adrenocortical hyperplasia (33%-40%).

Question 2

@# 8. A slimly built 60-year-old woman presents with anorexia, diarrhoea, and weight loss. Barium meal shows multiple filling defects in the stomach with thickened gastric rugae. Colonoscopy shows multiple colonic polyps. The top differential is

A. Peutz-Jeghers syndrome

B. Familial adenomatous polyposis

C. Cronkhite-Canada syndrome

D. Cowden syndrome

E. Turcot’s syndrome

Answer 2

8. C. Cronkhite-Canada syndrome

Cronkhite-Canada syndrome occurs in older patients with an average age of 60 with no familial predisposition.

The histologic appearance of the GI polyps resembles that of juvenile polyps, and they are characteristically distributed throughout the stomach.

They are commonly small, sessile and characterised by cystic dilatation of the glands and inflammation of the lamina propria.

Patients commonly present with abdominal pain, protein-losing diarrhoea, anorexia and weight loss. Dystrophic nail changes and alopecia usually appear after the onset of GI symptoms.

Question 3

@# 14. A 70-year-old man presents with rectal bleeding. Flexible sigmoidoscopy shows a circumferential tumour in the upper third of the anal canal. An MRI performed for staging shows locoregional lymphadenopathy. The lymph node group most likely to be involved is

A. Superficial inguinal

B. Common iliac

C. Pudendal

D. External iliac

E. Paraortic

Answer 3

14. A. Superficial inguinal

Metastatic spread to regional lymph nodes represents the most common mode of tumour spread from cancer of the anal canal and margin. Nodal metastasis is more likely in cases of larger tumour size or a poorly differentiated anal tumour. Metastasis most commonly occurs to the perirectal nodes, with inguinal nodal spread being the second most common location of nodal metastasis.

Question 4

@# 20. A 76-year old woman with 6 months’ history of progressive weight loss and altered bowel habits is referred for a CT scan of the abdomen and pelvis. The examination shows several hypoattenuating lesions on Segments II and III of the liver that are highly suspicious for malignancy. Blood biochemistry with tumour markers shows a normal AFP and CA 19-9 but raised CEA. LFTs are minimally deranged. The case is discussed at MDT.
What is the most likely differential diagnosis and further management plan out of the options given?

A. Primary hepatocellular carcinoma - liver biopsy

B. Hepatic adenoma - liver resection

C. Probable lung cancer - CT chest

D. Metastatic renal carcinoma - renal biopsy

E. Metastasis from colonic adenocarcinoma colonoscopy

Answer 4

20. E. Metastasis from colonic adenocarcinoma - colonoscopy

Question 5

@# 22. Which statement is not associated with transient patellar dislocation?

A. The medial patellar retinaculum frequently demonstrates high T2W signal changes.

B. A tibial tuberosity to trochlear groove distance of <1.5 cm.

C. Trochlear dysplasia is a predisposing condition.

D. There is an increase in the ratio of the patellar tendon to the patellar length.

E. Bone contusions of the anterolateral aspect of the lateral femoral condyle.

Answer 5

22. B. A tibial tuberosity to trochlear groove distance of <1.5 cm.

Transient patellar dislocation is the dislocation of the patella laterally and subsequent relocation.

Trochlear dysplasia, patella alta (increase in the ratio of the patella tendon to the patella length) and an increase in the tibial tuberosity trochlear groove (TT-TG) distance are associated factors.

TT-TG >20 mm is abnormal and 15-20 mm is considered borderline change.

TT-TG less than 15 mm is within normal limits.

Contusional marrow oedema is often seen in the medial patellar facet and the lateral femoral condyle.

The medial patellar retinaculum and/or medial patellofemoral ligament (MPFL) may be torn or show a pattern of strain injury.

Question 6

@# 27. A young woman with a palpable nodule in the breast undergoes a contrast enhanced MRI breast for further evaluation. MRI demonstrates typical multiple non-enhancing internal septations. What is the diagnosis?

A. Fibrocystic change

B. Abscess

C. Atypia

D. Fibroadenoma

E. Hydatid cyst

Answer 6

27. D. Fibroadenoma

Non-enhancing internal septations were initially described to have a high specificity in fibroadenoma diagnosis; however, this feature has recently been described in PTs and cancers and thus has little value when considered alone .Although morphological findings are important in lesion characterisation, breast cancers may have a benign appearance. In particular, 30% of familial breast cancers revealed a mass showing benign morphological features with a round or oval shape, smooth margins and homogeneous internal enhancement. It should be considered that all enhancing masses in women with genetic risks are suitable for biopsy when there is a lack of typical cyst or fat necrosis findings.

Question 7

@# 31. A 66-year-old man with central chest pain radiating to the back is brought into the A&E department. A chest X-ray is read as unremarkable and a contrast CT is organised. The contrast CT shows an acute dissection flap in the aortic arch at the origin of the left common
carotid trunk extending through the descending thoracic aorta, into the proximal
abdominal aorta at the level of the renal arteries. Which of the following best classifies this dissection type?

A. DeBakey 1 - Stanford A

B. DeBakey 2 - Stanford A

C. DeBakey 3 - Stanford A

D. DeBakey 1 - Stanford B

E. DeBakey 2 - Stanford B

Answer 7

31. A. DeBakey 1 - Stanford A

Question 8

@# 33. All of the following are accepted indications for MRI breast in breast cancer imaging, except

A. Response to chemotherapy

B. Patients with breast augmentation

C. High-risk screening

D. Differentiate residual disease from post-surgical scar

F. . Breast cancer recurrence

Answer 8

33. D. Differentiate residual disease from post-surgical scar

MRI of the breast has evolved into an important adjunctive tool with multiple indications in breast imaging, as recommended by US and European guidelines. Breast MRI is currently the most sensitive detection technique for breast cancer diagnosis. The indications are staging before treatment planning, screening of high-risk women, evaluation of response to neoadjuvant chemotherapy, patients with breast augmentation or reconstruction, occult primary breast cancer, breast cancer recurrence, identifying residual tumour in positive surgical margins and characterisation of equivocal findings. Differentiating early post-operative scarring from residual breast tumour is not possible because of similar enhancement characteristics of post-surgical scarring.

Question 9

@# 37. An 8-week old boy presents with profound cyanosis with associated congestive cardiac failure. Imaging demonstrates a localised concurrent aortic coarctation. The likeliest underlying diagnosis would be

A. Tetralogy of Fallot

B. Truncus arteriosus

C. Transposition of the great arteries

D. Hypoplastic left heart syndrome

E. Tricuspid atresia

Answer 9

37. D. Hypoplastic left heart syndrome

Hypoplastic left heart syndrome presents with early onset (days) of cyanosis and heart failure, leading to collapse and death in a few weeks of life. Associated cardiac malformations include pre- and post-ductal coarctation of the aorta, PDA, VSD, patent foramen ovale and so on.
Truncus arteriosus presents with minimal cyanosis in newborn infants; signs of heart failure are usually absent. Heart failure is evident in older infants.
Tetralogy of Fallot presents in early infancy with cyanosis, usually not present in early infancy, leading to clubbing; dyspnoea, heart failure, failure to thrive and paroxysmal hypercyanotic spells. X-ray shows a boot-shaped heart with oligaemic lungs.
Transposition of the great arteries is a medical emergency. Infants usually present in the first few hours or days with worsening duct-dependent cyanosis. Hypoxia is severe, but heart failure is not a feature. X-ray shows an ‘egg on end’ or ‘egg on string’ appearance.
Tricuspid atresia presents in the first few days of life with increasing cyanosis; other clinical features are dependent on associated PDA or VSD.

Question 10

@# 38. All the following are useful features for differentiating true lumen from false lumen, except

A. In case of lumen wrapping, the inner lumen is true.

B. Beak sign indicates a false lumen.

C. A false lumen is often larger than a true lumen.

D. A cobweb sign demarcates the true lumen.

E. Intimal calcification surrounds the true lumen.

Answer 10

38. D. A cobweb sign demarcates the true lumen.

The beak sign and a larger cross-sectional area were the most useful indicators of the false lumen for both acute and chronic dissections. Features generally indicative of the true lumen included outer wall calcification and eccentric flap calcification. In cases showing one lumen wrapping around the other lumen in the aortic arch, the inner lumen was invariably the true lumen. Outer wall calcification always indicated the true lumen on scans of acute dissections. False lumen thrombus was significantly more frequent in chronic dissections than acute dissections. Cobwebs are specific for the false lumen but are only rarely observed.

Question 11

@# 41. A 74 year-old man presents with neck pain, with right upper-arm pain and radicular symptoms at the lateral aspect of the forearm and tingling in the thumb. What is the most likely finding on the MRI?

A. Central disc bulge at C3/4 with severe cord compression

B. Right foraminal disc osteophyte at C2/3

C. Right foraminal disc osteophyte at C4/5

D. Right foraminal disc osteophyte at C5/6

E. Right foraminal disc osteophyte at C3/4

Answer 11

41. D. Right foraminal disc osteophyte at C5/6

Lateral aspect of the forearm and the thumb corresponds to the C6 dermatome. Foraminal osteophyte at C5/6 will impinge upon the exiting C6 nerve root. (cf. foraminal osteophyte at a thoracic or lumbar level, e.g., T4/5 or L4/5, which will impinge upon the exiting T4 or L4 nerve roots, subject to the discrepancy between number of cervical vertebra and cervical roots. Note that the exiting root at C7/T1 is C8.)

Question 12

@# 42. A 35-year-old man involved in a major RTA undergoes a lateral view of the cervical spine m the resus on arrival. All of the following are features associated with atlanto occipital dislocation, except

A. Soft-tissue swelling anterior to C2 by >10 mm.

B. Basion dens interval >12 mm.

C. Odd’s ratio >1.

D. X-ray can often be normal.

E. Incongruity of articular surface of atlas and occipital condyles.

Answer 12

42. D. X-ray can often be normal.

Atlanto-occipital dislocation shows the following on lateral radiograph of the cervical spine: >10 mm soft-tissue swelling anterior to C2, with pathological convexity (80%), basion-dens interval of >12 mm, odd’s ratio (distance between the basion and the posterior arch of the atlas divided by opisthion and anterior arch of atlas) >1, and basion-posterior axial line interval >12 mm anterior/>4 mm posterior to axial line.
Direct signs include loss of congruity of articular surfaces of atlas and occipital condyle. Normal X-ray in the presence of atlanto-occipital dislocation is rare.

Question 13

@# 43. A child presents with an abnormally shaped cranium. There is hypertelorism and the skull vault appears short and widened. The anterior cranial fossa appears shortened. Which sutures are likely to have fused early?

A. Sagittal

B. Coronal

C. Metopic

D. Lambdoid

E. Unilateral coronal and lambdoid

Answer 13

43. B. Coronal

The appearance here describes brachycephaly. Craniosynostosis is the premature fusion of cranial sutures and may be isolated or may present as part of a craniofacial syndrome. It typically alters the shape of the cranial vault. Broad categories include simple craniosynostosis, involving only one suture, or compound craniosynostosis, where two or more sutures are involved.

Question 14

@# 44. A 37 year old woman with newly diagnosed hypertension undergoes an MRA, which shows alternate areas of stricture and dilatation to the right renal artery, sparing the origin. Which of the following is the least likely association?

A. String-of-beads appearance of the contralateral renal artery

B. String-of-beads appearance of the extracranial internal carotid artery

C. String of-beads appearance of the retinal artery

D. String-of-beads appearance of the vertebral artery

E. String-of-beads appearance of the SMA

Answer 14

44. C. String-of-beads appearance of the retinal artery

Fibromuscular dysplasia (FMD) is an idiopathic, segmentary, non-inflammatory and non atherosclerotic disease that can affect all layers of both small- and medium-calibre arteries. Vascular loops, fusiform vascular ectasia and a string-of-beads aspect are typical presentations. Arterial dissection, aneurysm and subarachnoid haemorrhage are less typical radiologic presentations.
The affected arteries are mainly the renal arteries, extracranial carotid and vertebral arteries, mesenteric arteries and intracranial carotid arteries. Central retinal artery occlusion is a rarely recognised feature of fibromuscular dysplasia.

Question 15

@# 51. A 30-year-old woman who is 36 weeks pregnant is being evaluated with targeted ultrasound to investigate a recently noticed breast lump. Ultrasound images are reported to show a well-circumscribed, wider than tall, hypoechoic, solid mass corresponding to the abnormality. Follow-up imaging to assess stability shows progressive regression in size of the mass post-partum. What is the likely diagnosis?

A. Fibrocystic change

B. Fat necrosis

C. Inflamed intramammary node

D. Lactating adenoma

E. Breast hamartoma

Answer 15

51. D. Lactating adenoma

Lactating adenomas are newly discovered painless lumps that appear during the third trimester or lactation. They are a freely mobile, homogenous hypoechoic or isoechoic mass with posterior acoustic enhancement (most common) and septa. The lesion regresses after breastfeeding.

Question 16

@# 61. A 72-year-old man with a 5.8 cm aortic aneurysm increasing at a rate of 1.2 cm every year is being worked up for an EVAR. Planning CT with multiformatted images and 3D volume-rendered reconstructed images have been obtained. All of the following measurements need to be provided at the MDT by the vascular radiologist, except

A. Size of aorta at the level of the renal artery

B. Size of aorta at the bifurcation

C. Largest diameter of the aneurysm

D. Size of the common iliac artery

E. Distance from aortic bifurcation to common iliac bifurcation

Answer 16

61. A. Size of aorta at the level of the renal artery

Several important characteristics of the aneurysm must be accurately described for standard stent-graft sizing.

The aneurysm is described in terms of the proximal landing zone, the aneurysm sac, the distal landing zone and the vascular access.

Reported diameters should include the aorta at the level of the most inferior renal artery, the aortic neck 15 mm distal to the lowest renal artery, aorta at the bifurcation, the largest aneurysm sac diameter and the size of the common iliac arteries.

Additional measurements include the length of the aneurysm neck, the length from the lowest renal artery to the aortic bifurcation and the length of the aneurysm sac.

The length of the distal landing zone is described as the distance from the aortic bifurcation to the common iliac artery bifurcation.

Minimal diameters should be recorded in the distal landing zone and external iliac artery access vessels.

Question 17

@# 74. A 67-year-old man with a family history of colorectal cancer and a background history of COPD has been referred for a screening barium enema, which shows multiple small filling defects throughout the descending and sigmoid colon but no colonic mass. The most likely diagnosis is

A. Hereditary non-polyposis syndrome

B. Ulcerative colitis

C. Crohn’s disease

D. Colonic serosal metastasis

E. Pneumatosis coli

Answer 17

74. E. Pneumatosis coli

Pneumatosis is the presence of gas bubbles within the wall of the involved segment of bowel. It is seen in a wide variety of conditions. It is widely divided into two groups: primary (idiopathic) and secondary. Conditions associated with secondary pneumatosis include obstruction, pulmonary disease such as COPD and asthma, vascular conditions such as ischaemia and infarction, inflammatory conditions such as Crohn’s and UC, necrotising enterocolitis, drugs such as steroids and chemotherapy, collagen vascular diseases such as scleroderma, SLE and dermatomyositis.

Question 18

@# 82. When performing an M R arthrogram, what is the correct concentration of gadolinium (Gd-DTPA, Magnovist) that should be injected into the joint prior to imaging?

A. 0.01 mmol/L

B. 0.1 mmol/L

C. 2.0 mmol/L

D. 20 mmol/L

E. 200 mmol/L

Answer 18

82. C. 2.0 mmol/L

It is important when performing MR arthrography that the correct concentration of gadolinium is used in order to achieve the best arthrographic result. Too concentrated or too dilute a solution will result in a suboptimal study. A dose of 2 mmol/L is the recognised concentration of Gd-DTPA; this can be achieved by adding 0.8 mL of neat Gd-DTPA to 100 mL of normal saline. An alternative method would be to inject 4 mL of Gd-DTPA into a 500 mL bag of normal saline to achieve the same 2 mmol/L concentration. It is also important to avoid inadvertent intra-articular injection of air, as this will result in susceptibility artefact at the subsequent MRI that may limit its diagnostic accuracy.

Question 19

@# 84. A skeletal survey was performed on a 2-year-old boy with short stature. The lateral film of the spine revealed abnormal vertebral bodies with a central anterior ‘beak’ and generalised flattening. Radiographs of the hands showed a pointed proximal fifth metacarpal base with a notch at the ulnar aspect. Which of the following is the most likely diagnosis?

A. Hunter syndrome

B. Hurler syndrome

C. Morquio syndrome

D. Achondroplasia

E. Nail patella syndrome

Answer 19

84. C. Morquio syndrome

The mucopolysaccharidoses are a group of inherited diseases characterised by abnormal storage and excretion in the urine of various mucopolysaccharides.

Patients with these diseases have short stature and characteristic plain film findings.

A characteristic finding in the hands is a pointed proximal fifth metacarpal base that has a notched appearance to the ulnar aspect.

There is generalised flattening of the vertebral bodies (platyspondyly).

Hunter and Hurler syndromes demonstrate an anterior vertebral beak that is inferiorly positioned, whereas Morquio syndrome demonstrates an anterior vertebral beak that is centrally positioned.

Although achondroplasia can cause rounded anterior beaking in vertebra of the upper lumbar spine, the findings described within the hands are more typical of the mucopolysaccharidoses.

Question 20

@# 85. A middle-aged woman underwent uterine fibroid embolisation (UFE) recently. All of the following statements regarding prognosis are correct, except

A. The enhancement pattern correlates well with treatment response.

B. Pedunculated fibroids with narrow pedicle are unfavourable.

C. Fibroids more than 15 cm in size may continue to give bulk symptoms.

D. Progressive liquefaction of fibroid post-treatment results in a high signal on T2W images.

E. Fibroids with high T1 signal pretreatment respond better to UFE.

Answer 20

85. E. Fibroids with high Tl signal pretreatment respond better to UFE.

UFE is a minimally invasive treatment for uterine fibroids. MRI should be used to evaluate patients before and after UFE to accurately assess fibroid location within the uterus.
fibroid number and size, and the presence or absence of fibroid enhancement on contrast material-enhanced images.
Absolute contraindications include pregnancy, known or suspected gynaecologic malignancy, and current uterine or adnexal infection; relative contraindications include contrast material allergy, coagulopathy and renal failure. Pedunculated subserosal fibroids with a narrow stalk (<2-3 cm) are a relative contraindication to UFE because of the potential risk of detachment. Cervical fibroids tend to respond less favourably. The maximum size threshold for embolisation is 13-15 cm. Above this, the post-embolisation volume may still result in bulk symptoms, and the necrosis from a large fibroid may result in a protracted post embolisation syndrome.
Fibroids with increased cellular content and degenerate fibroids may demonstrate a high signal on T2-weighted MRI; however, a heterogeneous or markedly hyperintense T2 signal suggests degeneration. Completely hyalinised fibroids have low T2. T1 hyperintensity pre-MRI suggests fatty or haemorrhagic/red degeneration and is a negative predictor of success with a lower reduction in vascularity compared to fibroids with a low T1 signal.
After successful embolisation, fibroids may undergo progressive liquefaction with increasing T2 signal. Volume reduction is greater in T2 hyperintense fibroids and hypervascular fibroids compared to hypovascular ones. Persistent enhancement post embolisation is sign of incomplete fibroid infarction. An increase in signal on T1-weighted images is typically observed immediately after embolisation.

Question 21

@# 87. A 23-year-old woman with large bilateral low density renal lesions on CT is also known to have a large posterior fossa brain tumour. Review of the old notes reveals that she has
had several visits to the ophthalmology department. The condition that she is most likely to be
suffering from is

A. Tuberous sclerosis

B. Von Hippel-Lindau syndrome

C. Wunderlich syndrome

D. NF1

E. No syndrome the findings are unrelated

Answer 21

87. B. Von Hippel-Lindau syndrome

Von Hippel-Lindau (VHL) disease is a rare, inherited, multisystem disorder that is characterised by development of a variety of benign and malignant tumours. The spectrum of clinical
manifestations of the disease is broad. These include retinal and CNS haemangioblastomas (mostly affecting cerebellum/posterior fossa), endolymphatic sac tumours, renal cysts and tumours (renal cell carcinoma), pancreatic cysts and tumours (serous cystadenoma, adenocarcinoma and neuroendocrine tumours), pheochromocytomas, and epididymal cystadenomas.
Retinal haemangioblastomas are among the most frequently and earliest detected VHL disease lesions.

Question 22

@# 89. An unenhanced CT brain performed on a young man with sudden severe occipital headache shows acute subarachnoid haemorrhage with most of the blood at the foramen magnum. Considering that the source is a ruptured aneurysm, what is the most likely location for the aneurysm in this patient?

A. ACOM

B. PCOM

C. ACA

D. AICA

E. PICA

Answer 22

89. E. PICA

The location of blood in cases of subarachnoid haemorrhage from a ruptured aneurysm can pinpoint the site of aneurysm in 70% of cases.

Question 23

@# 90. A 4-year-old girl presents with progressive enlargement of her right thigh, with episodes
of unprovoked bleeding from pigmented lesions over her right thigh, which have been present since birth. A lower limb venogram of the right kg demonstrates absence of the deep venous system, with varicose veins on the lateral aspect of the right leg. Which of the following is the most likely diagnosis?

A. Klippel-Trenaunay syndrome

B. Neurofibromatosis

C. Beckwith-Wiedemann syndrome

D. Macrodystrophia lipomatosis

E. Maffuci syndrome

Answer 23

90. A. Klippel-Trenaunay syndrome

Klippel-Trenaunay syndrome is a sporadic, rare, mesodermal abnormality that usually affects a single lower limb. It is characterised by a triad of a port wine naevus (unilateral cutaneous capillary haemangioma often in a dermatomal distribution on the affected limb), overgrowth of distal digits/entire extremity (involving soft tissue and bone) and varicose veins on the lateral aspect of the affected limb. Although the other options can produce limb hypertrophy, they would not be expected to show all the features of the triad described.

Question 24

@# 101. A 7-year-old boy undergoes a plain CT brain for recent trauma, which reveals a cystic lesion in the cerebellum with a mural nodule laterally. No calcification is evident, but enhancement of the mural nodule is seen in post-contrast images. What is the most likely diagnosis in this patient?

A. Haemangioblastoma

B. Pilocytic astrocytoma

C. Giant cell astrocytoma

D. Pleomorphic xanthoastrocytoma

E. Lymphoma

Answer 24

101. A. Haemangioblastoma

Haemangioblastoma (HB) is a vascular tumour of the CNS. It occurs most often in the cerebellum, where it is the most common primary neoplasm in adults. Single tumours may be sporadic, but multiple tumours are almost always associated with VHL disease. The most common MR pattern of LIB is an enhancing solid mural nodule with an adjacent non-enhancing cyst.
The cyst is typically low on T1-weighted and high on T2-weighted images, but it can have areas of high T1 signal from fat or haemorrhage. HB can also look purely cystic, solid or a mural nodule with enhancing cystic wall. HB almost never calcifies.
Pilocytic astrocytoma are cystic, with larger mural nodule, calcification, thick walls and no contrast blush to the mural nodule on angiography.

Question 25

@# 104. Which of the following is not a limitation of CT imaging in staging of rectal cancer?

A. Poor tissue characterisation.

B. Inability to identify T4 tumour.

C. Non-visualisation of the mesorectal fascia.

D. Low sensitivity, specificity and accuracy in the detection of local nodal metastasis.

E. Sensitivity, specificity and accuracy are much lower in post radiation evaluation.

Answer 25

104. B. Inability to identify T4 tumour.

In the setting of primary rectal cancer, MRI is used to assist in staging, in identifying patients who may benefit from preoperative chemotherapy-radiation therapy, and in surgical planning.
Currently, surgical resection with stage-appropriate neoadjuvant combined-modality therapy is the mainstay in the treatment of rectal cancer. In the past decade, the increasingly widespread adoption of total mesorectal excision (TME) has resulted in a dramatic decline in the prevalence of local recurrence from 38% to less than 10%. TME is a surgical technique that entails cn bloc resection of the primary tumour and the mesorectum by means of dissection along the mesorectal fascial plane or the circumferential resection margin (CRM). The evolution of surgical techniques and the shift to neoadjuvant chemotherapy-radiation therapy, along with the prognostic heterogeneity of stage T3 tumours, necessitate accurate preoperative staging primarily in terms of tumour (T) and nodal (N) staging, depth of tumour invasion outside the muscularis propria (early versus advanced stage T3 tumours) and the relationship of the tumour to the potential CRM. Accurate assessment of these factors allows the triage of patients to up front surgical resection or short- or long course preoperative radiation therapy or chemotherapy-radiation therapy with appropriate modification of the CRM. Recent studies have shown that high-resolution MRI is a reliable and reproducible technique with high specificity’ (92%) for predicting a negative CRM, the relationship of the tumour to the CRM and the depth of tumour invasion outside the muscularis propria.

Question 26

@# 109. A 56-year-old woman post-renal transplant is being evaluated by renal ultrasound.
A small amount of fluid is noted around the graft. All of the following facts are true regarding renal and vascular complications post-transplant, except

A. Loss of corticomedullary differentiation is a feature of reduced renal function.

B. Reversal of diastolic flow is specific for renal vein thrombosis.

C. Extrarenal arteriovenous fistulas are related to surgical technique.

D. Intrarenal arteriovenous fistulas are the result of percutaneous biopsy.

E. Crescentic peritransplant fluid collections immediately post-transplantation are not usually significant

Answer 26

109. B. Reversal of diastolic flow is specific for renal vein thrombosis.

Acute tubular necrosis is the most common cause of ‘delayed graft function’, whereas chronic rejection is the most common cause of late graft loss.
US findings of diminished renal function include renal enlargement, increased cortical thickness, increased or decreased echogenicity of the renal cortex, loss of corticomedullary differentiation, prominent pyramids, collecting system thickening and effacement of the central sinus echo complex. Elevated resistive index (>0.8) is a non-specific parameter of renal transplant dysfunction; reversal of diastolic flow may also be seen. Renal artery stenosis is the most common vascular complication of transplantation. Doppler criteria include (1) velocities of greater than 2 m/sec, (2) a velocity gradient between stenotic and prestenotic segments of more than 2:1 and (3) marked distal turbulence.

Although reversal of diastolic flow is non-specific, the combination with absent venous flow is virtually diagnostic of renal vein thrombosis. Renal artery thrombosis is diagnosed by lack of intrarenal venous and arterial flow. Renal vein stenosis results in three- to fourfold increase in flow velocity. Intrarenal arteriovenous fistulas and pseudoaneurysms are the result of vascular trauma during percutaneous biopsy. Extrarenal arteriovenous fistulas and pseudoaneurysms are extremely uncommon. They typically occur as a result of surgical technique rather than percutaneous biopsy.

Small crescentic peritransplant fluid collections seen immediately after transplantation are most likely haematomas or seromas and are not significant More complex collections identified later in the post operative period with clinical evidence of infection may represent abscesses. Although the appearance of urinomas is non-specific, internal septations are seen less often than in haematomas. Lymphocele results in a rounded collection along the mid-ureter, associated with hydronephrosis.

Question 27

@# 112. A wrist arthrogram is performed for instability and 5 mL of contrast is injected into the radiocarpal joint. The contrast is seen to extend lateral to the lunate into the mid carpal joint Which of the following is this diagnostic of?

A. Contrast extravasation secondary to the large volume of contrast injected

B. Scapholunate ligament tear

C. Lunatotriquetral ligament tear

D. Distal radioulnar joint (DRUJ) disruption

E. Triangular fibrocartilage (TFC) tear

Answer 27

112. B. Scapholunate ligament tear

Single-compartment and three-compartment injection techniques have been described for wrist magnetic resonance arthrography.

In the three compartment technique, the mid-carpal and distal radio ulnar joints are initially injected with approximately 1-1.5 ml. of iodinated contrast under fluoroscopic guidance. About 3 ml. of dilute gadolinium is then injected into the radiocarpal compartment after confirmation of the needle-tip position with the injection of a small volume of iodinated contrast.

Contrast should normally be confined to the radiocarpal joint with no leak of contrast into the DRUJ proximally or the mid carpal joint distally.

If contrast extends lateral to the lunate, between it and the scaphoid this is diagnostic of a full thickness scapholunate ligament tear.

Question 28

@# 114. A child is admitted to the A&E department following head injury. A CT scan of the head is performed and, incidentally, a well-defined lobulated heterogeneous mass containing calcification is seen to arise from the floor of the fourth ventricle. Which of the following is the most likely diagnosis?

A. Glioma

B. Pilocytic astrocytoma

C. Medulloblastoma

D. Ependymoma

E. Brainstem glioma

Answer 28

114. D. Ependymoma

Medulloblastoma is the most common neoplasm of the posterior fossa in childhood and is the most malignant infratentorial tumour; however, it arises from the roof of the fourth ventricle. Calcification is an atypical feature of medulloblastoma. Brainstem gliomas displace the fourth ventricle. Pilocytic astrocytoma commonly occurs in the cerebellar hemispheres, not in the fourth ventricle.
Ependymoma is the third most common posterior fossa tumour in children. The point of origin is the floor of the fourth ventricle in ependymoma, versus the roof in medulloblastoma. Calcification is a common feature seen in 50% of ependymoma cases, and contrast enhancement is heterogeneous. Although not pathognomonic, the plastic nature of ependymoma results in the classic presentation of a fourth ventricle mass extending through the foramen of Luschka (15%) or foramen of Magendie (60%).