TEST PAPER 4 Flashcards
@# 1.A 71-year old man with a long history of alcohol-related liver cirrhosis showed a subtlebut equivocal area of abnormality on a screening ultrasound. His AFP was raised at 2,000.An MRI of the liver with contrast is performed. All of the following are expected featuresof infiltrative HCC on MRI, except
A. Hyperintense on MR images acquired during the hepatobiliary phase after injection ofhepatocyte-specific contrast agent.
B. A reticular appearance of the tumour can be seen during the venous and equilibriumphase.
C. Washout appearance of the tumour is usually reported as irregular andheterogeneous.
D. Infiltrative HCC may commonly appear as iso- or hypointense on images obtainedduring the arterial phase.
E. Infiltrative HCC may be difficult to discern from underlying heterogeneous cirrhosisbecause of its permeative appearance.
1.A. Hyperintense on MR images acquired during the hepatobiliary phase after injection of
hepatocytes specific contrast agent
At contrast-enhanced CT and MR imaging, infiltrative HCC may be difficult to discern from underlying heterogeneous cirrhosis because of its permeative appearance, its minimal and inconsistent arterial enhancement and the heterogeneous washout appearance that occurs during the venous phase.
The enhancement pattern of infiltrative HCC seen on images obtained during the hepatic arterial phase has been reported as minimal, patchy or miliary.
Although arterial hyperenhancement is a key diagnostic feature of nodular and massive HCC, infiltrative HCC may commonly appear as iso- or hypointense on images obtained during the arterial phase.
Washout appearance is a specific CT and MR imaging feature of typical nodular HCC.
Hypointensity relative to the surrounding liver parenchyma during the venous phase of enhancement remains a valid sign for the detection of infiltrative HCC.
However, washout appearance of the tumour is usually reported as irregular and heterogeneous and is less frequently seen in infiltrative HCC than in other HCC subtypes.
Moreover, a reticular appearance of the tumour has been seen on images obtained during the venous and equilibrium phases, possibly related to fibrosis.
Finally, the tumour generally appears as hypointense on MR images acquired during the hepatobiliary phase after injection of hepatocyte specific contrast agent because of the lack of contrast agent uptake.
2.Which of the following is false?
A. NSIPScleroderma
B. Sjögren’s syndromeLymphocytic interstitial pneumonitis (LIP)
C. Lofgren’s syndromeSystemic lupus erythematosus (SLE)
D. Loeffler’s syndromeAcute eosinophilia
E. Folded lungsAsbestosis
2.C. Lofgren’s syndrome Systemic lupus erythematosus (SLE)
NSIP is more common than UIP. Although NSIP is defined as idiopathic, the morphologicpattern is seen with connective-tissue diseases, hypersensitivity pneumonitis or drug exposure. LIP is exceedingly rare. It is seen as a secondary disease in association with Sjögren syndrome, HIV infection and variable immunodeficiency syndromes.
Löffler’s syndrome refers to simple pulmonary eosinophilia, with high eosinophil count in peripheral blood and fleeting air space opacities. Round atelectasis or folded lung is a recognised asbestos-related lung abnormality. Lofgren’s syndrome is an acute form of sarcoidosis characterised by erythema nodosum, bilateral hilar lymphadenopathy and polyarthralgia or polyarthritis.
3.Which one of the following statements regarding the testes is false?
A. Tubular ectasia of the testis is a benign condition.
B. Undescended testes are most commonly found in the inguinal canal.
C. Metastases are most commonly from prostate and lung primary.
D. Testicular cysts are mostly incidental and non-palpable.
E. Sertoli cell tumour is the most common malignant testicular tumour.
- E. Sertoli cell tumour is the most common malignant testicular tumour.
Cryptorchidism is defined as complete or partial failure of the intra-abdominal testes to descend
into the scrotal sac. The undescended testis may be positioned anywhere along the normal path of descent. The most common location is in the inguinal canal (72%), followed by prescrotal (20%). Simple testicular cysts are mostly found incidentally, non-palpable, in men above 40 years, located at the mediastinum testis. Testicular metastases are rare and a sign of advanced primary disease, mostly from the prostate (35%), lung (20%), melanoma, colon or kidney. They may appear discrete or diffusely infiltrate the parenchyma. Tubular ectasia of the rete testis is a benign condition resulting from partial or complete obliteration of the efferent ducts that cause ectasia of the rete testis. Germ cell tumours are the most common testicular malignancy.
4.A 21-year-old woman attends the A&E department with acute onset of pain in the right upperarm with limitation of mobility. The plain radiograph report describes a ‘fallen fragment’ sign.Which one of the following bony lesions does this finding refer to?
A. Giant cell tumour
B. Simple bone cyst
C. Eosinophilic granuloma
D. Aneurysmal bone cyst
E. Benign cortical defect
- B. Simple bone cyst
The fallen fragment sign comprises a small fragment that lies in the dependant portion of a radiolucent skeletal lesion. It is mostly recognised in radiograph, but analogous findings can be seen on CT or MRI.
A dependant bone fragment can result from a pathologic fracture through thin cortical wall of a simple bone cyst. After minor trauma periosteum and surrounding muscle prevents centrifugal displacement of fracture fragment. However, a fractured fragment can become dislodged and fall centrally. The fluid content of the lesion allows the fragment to drop to the dependant portion of the cyst.
- A 43-year-old patient with known diagnosis of AIDS presented with ataxia and progressive neurological deficits. MRI brain revealed patchy high signal on T2W images in the parieto occipital white matter. No mass effect or contrast enhancement was evident What is the diagnosis?
A. Primary CNS lymphoma
B. AIDS dementia complex
C. Progressive multifocal leukoencephalopathy
D. Periventricular leukomalacia
E. Encephalitis
- C. Progressive multifocal leukoencephalopathy
The most common imaging manifestation of HIV infection is global atrophy that is out of proportion to age. The finding of diffuse cerebral atrophy can be accompanied by diffuse, confluent, ill-defined areas of abnormally increased signal intensity on T2-weighted MRI of the periventricular white matter. No enhancement is noted. The findings may be accompanied by encephalopathy (AIDS dementia complex). These global abnormalities were previously attributed to a subacute encephalitis caused by HIV. It now seems likely that both HIV and CMV can cause subacute encephalitis and encephalopathy; these conditions have an identical non-specific imaging appearance. CMV encephalopathy appears to manifest itself late in the illness, whereas HIV dementia (although usually presenting late) can occasionally be the AIDS-defining illness.
Progressive multifocal leukoencephalopathy is the most serious focal lesion without significant mass effect. It is caused by the JC virus. On CT, the lesions have low attenuation. On MRI, they are of low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. They exhibit little or no mass effect. Although ring enhancement has been reported, these lesions generally do not enhance on CT or MRI. They often occur at the interface between the grey matter and the white matter and have a scalloped contour secondary to involvement of peripheral U-fibres. The parietal lobe is predominantly affected, but these lesions also occur in the periventricular white matter, posterior fossa, brainstem, spinal cord and even the basal ganglia.
- A 6-year-old with spina bifida has a chest X-ray performed for possible lower respiratory tract infection. The lungs are clear but there is a well-defined, round paraspinal mass with an air-fluid level. What is the most likely diagnosis?
A. Bronchogenic cyst
B. Morgagni hernia
C. Oesophageal duplication cyst
D. Cystic teratoma
E. Oesophageal tumour
- C. Oesophageal duplication cyst
Oesophageal duplication cysts are rare congenital anomalies. They are associated with vertebral anomalies (spina bifida, hemivertebrae, fusion defects). There is also an association with oesophageal atresia and small bowel duplication. Most cysts develop in the right posteroinferior mediastinum.
CT demonstrates a well-marginated round, oval or tubular shaped fluid-filled cystic structure that has a well-defined, thin wall. The cyst is of water attenuation with no enhancement of contents and no infiltration of surrounding structures. Malignant degeneration is rare.
Bronchogenic cyst is the most common cystic mediastinal mass that typically lies in the middle mediastinum, not in a paraspinal location; in addition, you would not expect an air-fluid level. Cystic teratoma is an anterior mediastinal mass. Morgagni hernia would be unlikely to cause a solitary round lesion; multiple structures would be expected.
@# 7. A 77-year-old man with weight loss and deranged LFTs had an ultrasound scan that showed multiple liver lesions suspicious for metastases. Contrast-enhanced CT of the chest and abdomen was done in search of the primary’. Which one of the following is the most common primary tumour that has hypovascular liver metastases?
A. Pancreas
B. Stomach
C. Colon
D. Kidney
E. Melanoma
- C. Colon
Liver metastases may be hypovascular or hypervascular.
Colon, lung, breast and gastric carcinomas are the most common tumours causing hypovascular liver metastases, and they typically show perilesional enhancement.
Neuroendocrine tumours (including carcinoid and islet cell tumours) renal cell carcinoma, breast, melanoma and thyroid carcinoma are the tumours most commonly causing hypervascular hepatic metastases, which may develop early enhancement with variable degrees of washout and peripheral rim enhancement.
Statistically, colonic metastases are more common than gastric carcinoma metastasis to the liver.
@# 8. A 65-year-old woman is recovering from a double lung transplant On the fourth day post-transplant, she starts complaining of shortness of breath. Clinical findings include some basal crackles; air entry seems satisfactory in the upper zones. An urgent chest X-ray is organised. Portable up-to-date chest X-ray shows evidence of pulmonary’ oedema. What is the most likely cause for this appearance?
A. Barotrauma
B. Acute graft failure
C. Volume overload
D. Response to antirejection treatment
E. Reimplantation response
- E. Reimplantation response
Ischaemia reperfusion injury or reimplantation response is a non-cardiogenic pulmonary oedema that typically occurs more than 24 hours after transplantation, peaks in severity on post-operative Day 4, and generally improves by the end of the first week. The oedema may continue up to 6 months post-operative; however, in most lung transplant recipients, it has cleared completely by 2 months. The radiographic and HRCT features are non-specific and may include perihilar ground-glass opacities, peribronchial and perivascular thickening, and reticular interstitial or airspace opacities located predominantly in the middle and lower lung lobes.
Acute rejection due to a cell-mediated immune response commonly occurs in the second week post-operative. HRCT features are also relatively non-specific and may include ground-glass opacities (often with basal distribution), peribronchial cuffing, septal thickening and pleural effusion.
@# 9. Cryptorchidism has an increased risk of development of all of the following testicular tumours, except
A. Leydig cell tumour
B. Seminoma
C. Yolk sac tumour
D. Embryonal cell tumour
E. Choriocarcinoma
- A. Leydig cell tumour
Cryptorchidism is associated with an increased risk of testicular germ cell tumours, more so with bilateral undescended testes. Germ cell tumours are seminomatous or non-seminomatous, which are embryonal cell tumour, yolk sac tumour, choriocarcinoma and teratoma.
Sertoli cell and Leydig cell tumours are non-germ cell tumours.
@# 10. A 15-year-old teenager presents with a worsening pain in his right ankle. He is an active sports player and plays football for the school club. A radiograph reveals an undisplaced fragment in the medial aspect of the talar dome with a small lucent line around it.
All of the following are well-recognised locations for osteochondral lesions or defects, except
A. Lateral aspect of the medial femoral condyle
B. Medial aspect of the talar dome
C. Lateral aspect of the medial tibial plateau
D. Anterior aspect of the capitellum
E. Humeral head
- C. Lateral aspect of the medial tibial plateau
Osteochondral defect (OCD) (previously called osteochondritis dissecans) may result directly from trauma or secondarily from loss of blood supply to an area of subchondral bone, resulting in avascular necrosis. The overlying cartilage, which is nourished by synovial fluid, remains intact to variable degrees. As the necrotic bone is resorbed, the overlying cartilage loses its support. Without its cartilage cover, the bony fragment may become dislodged into the joint.
Common sites of involvement include the lateral aspect of the medial femoral condyle, followed by the talar dome (posteromedial more than anteromedial), anterolateral aspect of the capitellum and the tibial plafond. Rarer sites include navicular, femoral head, humeral head, glenoid and scaphoid.
MRI Grading of OCD
I. Marrow oedema (stable).
II. Articular cartilage breached. Low-signal rim surrounding fragment indicates fibrous attachment (stable).
III. Pockets of fluid (high signal on T2-weighted images) around undetached and undisplaced osteochondral fragment (unstable).
IV. Displaced osteochondral fragment (unstable).
@# 11. A 35-year-old woman with pre-eclampsia underwent a CT of the brain to exclude intracranial haemorrhage. The CT revealed low attenuation in the white matter of the posterior aspect of both cerebral hemispheres. The abnormal area appeared low on T1W and high on T2W images and was isointense on DWI. No contrast enhancement was evident. What is the diagnosis?
A. Periventricular leukomalacia
B. Progressive multifocal leukoencephalopathy
C. Encephalitis
D. Reversible posterior leukoencephalopathy syndrome
E. CNS lymphoma
- D. Reversible posterior leukoencephalopathy syndrome
Reversible posterior leukoencephalopathy syndrome also known as posterior reversible encephalopathy syndrome (PRES), is most commonly encountered in association with acute hypertension, preeclampsia or eclampsia, renal disease, sepsis and exposure to immunosuppressants. At CT or MR imaging, the brain typically demonstrates focal regions of symmetric hemispheric oedema. The parietal and occipital lobes are most commonly affected, followed by the frontal lobes, the inferior temporal-occipital junction and the cerebellum. Lesion confluence may develop as the extent of oedema increases. MR DWI was instrumental in establishing and consistently demonstrating that the areas of abnormality represent vasogenic oedema. The oedema usually completely reverses. Focal or patchy areas of PRES vasogenic oedema may also be seen in the basal ganglia, brainstem and deep white matter (external/internal capsule). When they accompany hemispheric or cerebellar PRES, it is easy to recognise these. Present in isolation or when the hemispheric pattern is incompletely expressed (partial/ asymmetric), diagnosis of PRES can be challenging. If cerebellar or brainstem involvement are extensive, hydrocephalus and brainstem compression may occur. Focal areas of restricted diffusion (likely representing infarction or tissue injury with cytotoxic oedema) are uncommon (11%-26%) and may be associated with an adverse outcome. Haemorrhage (focal haematoma, isolated sulcal/subarachnoid blood or protein) is seen in approximately 15% of patients.
- A male infant is bom at 39 + 3 weeks gestation. Prenatal ultrasound demonstrated a partly cystic, partly echogenic mass in the right upper lobe. Shortly after delivery the infant is in respiratory distress. Initial chest X-ray demonstrates dense lungs bilaterally with increased volume on the right. On Day 2, a repeat chest X-ray demonstrates multiple air-filled cystic masses of varying sizes within the right upper lobe with mediastinal shift to the left. What is the most likely diagnosis?
A. Bronchogenic cyst
B. Morgagni hernia
C. Congenital cystic adenomatoid malformation
D. Congenital lobar emphysema
E. Hyaline membrane disease
- C. Congenital cystic adenomatoid malformation
Congenital cystic adenomatoid malformation is a developmental hamartomatous abnormality of lung with adenomatoid proliferation of cysts resembling bronchioles. It is thought to be caused by focal arrest in foetal lung development before the seventh week of gestation. Congenital cystic adenomatoid malformation represents 25% of all congenital lung lesions.
A CXR on Day 1 of life usually demonstrates dense lungs with increased volume on the affected side. On Day 2, a CXR usually demonstrates resorption of fluid from affected areas of lung, which are then replaced with air-containing spaces.
Communication with the tracheobronchial tree is maintained and the vascular supply and drainage are to the pulmonary circulation. There is a slight predilection for the upper lobes.
Newborns often present with respiratory distress secondary to mass effect and pulmonary compression or hypoplasia. The chest is dull to percussion with decreased air entry. Prenatal ultrasound shows a partly cystic, partly echogenic mass.
- A 78-vear-old woman with worsening right upper quadrant pain and worsening obstructive liver function test has a CT scan that shows a heterogeneous mass in the peripheral aspect of the liver with capsular retraction and segmental biliary duct dilatation proximal to the mass. There is no prior history of chronic Ever disease. What is the most likely diagnosis?
A. HCC
B. Siderotic nodule
C. Adenoma
D. Cholangiocarcinoma
E. Angiosarcoma
- D. Cholangiocarcinoma
Intrahepatic cholangiocarcinoma is the second most common primary hepatic tumour. Various risk factors have been reported for intrahepatic cholangiocarcinoma, and the radiologic and pathologic findings of this disease entity may differ depending on the underlying risk factors.
Intrahepatic cholangiocarcinoma can be classified into three types on the basis of gross morphologic features: mass forming (the most common), periductal infiltrating and intraductal growth. At CT, mass-forming intrahepatic cholangiocarcinoma usually appears as a homogeneous
low-attenuation mass with irregular peripheral enhancement; it can be accompanied by capsular retraction, satellite nodules and peripheral intrahepatic duct dilatation. Periductal infiltrating cholangiocarcinoma is characterised by growth along the dilated or narrowed bile duct without mass formation. On CT and MRI, diffuse periductal thickening and increased enhancement can be seen with a dilated or irregularly narrowed intrahepatic duct. Intraductal cholangiocarcinoma may manifest with various imaging patterns, including diffuse and marked duct ectasia either with or without a grossly visible papillary’ mass, an intraductal polypoid mass within localised ductal dilatation, intraductal cast-like lesions within a mildly dilated duct and a focal stricture like lesion with mild proximal ductal dilatation.
- A 36 year old immunocompromised woman with a knowm history of gestational trophoblastic disease showed bilateral bronchopneumonic infiltrates on chest X-ray.
An HRCT was suggested for further characterisation. The HRCT showed several areas of ground glass change surrounded by a rim of consolidation. The differential diagnosis for these findings would include all of the following, except
A. Wegner s granulomatosis
B. Invasive pulmonary aspergillosis
C. Choriocarcinoma metastasis
D. Sarcoidosis
E. Lymphangioleiomyomatosis
- E. Lymphangioleiomyomatosis
The reversed halo sign is characterised by a central ground-glass opacity- surrounded by denser air-space consolidation in the shape of a crescent or a ring. Causes include opportunistic and endemic fungal infection, with invasive pulmonary aspergillosis being the most common type. Other infectious causes include TB, bacterial infection, Legionnaires’ pneumonia and pneumocystis jiroveci pneumonia. Non-infectious causes include COP, sarcoidosis, lipoid pneumonia, Wegners granulomatosis and pulmonary embolism. Neoplastic causes include lymphomatoid granulomatosis, pulmonary adenocarcinoma and haemorrhagic metastasis like renal or choriocarcinoma. RFA and radiation therapy arc other causes. Lymphangioleiomyomatosis typically manifests as multiple thin walled cysts uniformly distributed throughout the lungs.
- Enhanced CT scan of an otherwise healthy motor vehicle accident victim demonstrates no enhancement of the right kidney on Day 0. A repeat contrast-enhanced CT scan obtained on Day 3 demonstrates a thin marginal rim of subcapsular enhancement of uniform thickness, described as the rim sign. The collecting system was mildly prominent. What is the most likely explanation?
A. Analgesic overuse
B. Renovascular compromise
C. Diabetes mellitus
D. Pyelonephritis
E. Developing hydronephrosis
- B. Renovascular compromise
The rim sign is associated with major vascular compromise in the kidney. This sign is most commonly seen with renal artery obstruction from thrombosis, embolus or dissection. On contrast enhanced CT or MRI, a 1 to 3-mm rim of subcapsular enhancement, paralleling the renal margin, can be seen as a result of preserved perfusion of the outer renal cortex by capsular perforating vessels. The finding may be accompanied by an abrupt termination of contrast material in the renal artery, referred to as the arterial cut-off sign. The rim sign of vascular compromise has also been described with renal vein thrombosis and acute tubular necrosis.
- A 44-year-old man presents with increasingly severe and disabling pain in the left inguinal and anterior thigh region. The pain is exacerbated by weight-bearing and relieved by rest. The patient mentions that the pain began 2 months ago, was acute in onset, and there was no preceding trauma. A radiograph of his left hip reveals a focal osteopaenic region within the left femoral head; this is no longer evident on a follow-up film 8 months later. Which of the following is the most likely diagnosis?
A. Osteomalacia
B. Avascular necrosis
C. Transient osteonecrosis
D. Transient osteoporosis
E. Occult fracture
- D. Transient osteoporosis
Transient osteoporosis is a rare, self-limiting condition that usually affects the hip. Classically, it is characterised by disabling pain in the hip without preceding trauma, and there is radiographic evidence of a focal region of osteopenia isolated to the hip. Although avascular necrosis can also present with a focal region of osteopenia in the early stages of the disease, transient osteoporosis resolves in 6-8 months, whereas avascular necrosis is usually progressive. It is thought that transient osteoporosis could represent a non traumatic form of Sudeck atrophy or reflex sympathetic dystrophy.
@# 17. A 35-year old woman with bilateral facial nerve palsy showed extensive nodular deposits with diffuse enhancement of the meninges on CECT of the brain. Which of the following imaging investigation will likely confirm the diagnosis?
A. MR angiogram of the circle of Willis
B. Ultrasound of the liver
C. Intravenous urogram
D. Plain chest radiograph
E. Plain radiograph of both hands
- D. Plain chest radiograph
Central nervous system involvement is seen in 5% of patients with systemic sarcoidosis (neurosarcoidosis). The most common parenchymal abnormality described in some series is multiple non enhancing periventricular white matter lesions, seen as high signal intensity on T2-weighted images.
Enhancing parenchymal mass lesions are also commonly reported. These lesions maybe mistaken for primary or metastatic tumour or tumefactive demyelination. Enhancing mass lesions are frequently associated with nearby leptomeningeal involvement. Leptomeningeal involvement is perhaps the most typical manifestation of central nervous system sarcoidosis, seen in about 40% of cases. This is usually seen as thickening and enhancement of the leptomeninges on contrast- enhanced T1 -weighted images. The enhancement may be diffuse or nodular. Leptomeningeal involvement around the hypothalamus and pituitary infundibulum may be seen with basilar leptomeningeal involvement or as an isolated finding. Cranial nerve involvement is also described. Any cranial nerve can be affected, but the most common cranial nerve deficit involves the facial nerve (VII), whereas radiographically the optic nerves (II) arc most commonly abnormal.
@# 18. A 10-month-old infant attends the local infectious diseases unit with his mother who recently emigrated from Zimbabwe. The child has shortness of breath, fever and bilateral inspiratory crackles. Chest X ray demonstrates diffuse bilateral ground-glass opacification. What is the most likely diagnosis?
A. Varicella pneumonia
B. Round pneumonia
C. Pneumocystis pneumonia (PCP)
D. Bronchopulmonary dysplasia
E. Congestive cardiac failure
- C. Pneumocystis pneumonia (PCP)
PCP is the most common opportunistic infection in immunosuppressed children, occurring in up to 90% of HIV-positive patients. A clinico-pathological and radiological continuum has been reported since the earliest documented cases of PCP. At one end of the spectrum are children with a florid clinical course, who progress from health to death in days. They show marked hypoxia and rapid radiographic evolution of parahilar granular infiltrates to extensive bilateral airspace opacification. Pathologically, an extensive foamy alveolar exudate is seen. Conversely, there are those with an insidious presentation, less profound hypoxia and a slower recovery. These patients tend not to progress to alveolar opacification but show persistent bilateral granular or ground-glass opacification, representing relative prominence of interstitial pulmonary involvement.
- A 65-year old hepatitis C-positive man is found to have a liver mass on screening ultrasound. A suspicion of HCC was raised. Which one of the following statements regarding HCC screening is false?
A. HCC is characteristically hyperechoic on ultrasound.
B. The majority of nodules that measure less than 1 cm are not HCC.
C. It develops in a background of preexisting liver parenchymal damage.
D. HCC is commonly diagnosed on the basis of imaging features alone, without histologic confirmation.
E. The nodules that are suspicious for HCC are new nodules that measure more than 1 cm or nodules that enlarge over a time interval.
- A. HCC is characteristically hyperechoic on ultrasound.
HCC does not have a characteristic appearance at US. The lesions are typically hypoechoic, but they can be hyperechoic or have mixed echogenicity. The majority of nodules that measure less than 1 cm are not HCC. Detected nodules that measure less than 1 cm should be rescanned at a 3-month interval with the modality by which the lesions were first identified.
If the nodules remain stable for a 2-year period, regular 6 month follow-up examinations can be resumed for routine surveillance. The nodules that arc suspicious for HCC are new nodules that measure more than 1 cm or nodules that enlarge over a time interval. These suspicious nodules require immediate further investigation with multiphasic CT or MRI.
The radiologic diagnosis of HCC can be made at either CT or MR imaging, provided that a multiphasic contrast material-enhanced study is used. Characteristically, HCC enhances during the arterial phase because of its blood supply from abnormal hepatic arteries. Contrast medium in the surrounding liver parenchyma is diluted during this phase, because the parenchymal blood supply arises mostly from the portal veins, which are not yet opacified. In the portal venous phase, the surrounding liver parenchyma becomes relatively hyperattenuated and the lesion is perceived to be hypoattenuated because of its lack of portal venous supply. This appearance is the so called washout effect. Occasionally, washout is evident only during a delayed-phase sequence.
HCC differs from most malignancies because it is commonly diagnosed on the basis of imaging features alone, without histologic confirmation.
- A 42-year-old factory worker complains of chest tightness and shortness of breath during the early days of the week, settling down during the weekend over the last several months.
Chest radiograph is normal. HRCT is requested for further evaluation. What do you expect the HRCT to show?
A. Crazy paving pattern
B. Patchy ground-glass opacities with centrilobular nodules
C. Perilymphatic nodules with beaded fissures
D. Central bronchiectasis
E. Extensive mediastinal and hilar lymphadenopathy
- B. Patchy ground-glass opacities with centrilobular nodules
In acute hypersensitive pneumonitis, symptoms may begin after patients return to an environment from which they have been absent for a while (e.g., resuming work following weekends
or holidays). Chest radiographs obtained in many patients with hypersensitivity pneumonitis are normal. HRCT typically shows patchy ground-glass opacities and centrilobular nodules. Respiratory bronchiolitis-interstitial lung disease is a smoking-related lung disease that has similar imaging features.
Perilymphatic nodules and beaded features are features of sarcoidosis, while central bronchiectasis is a typical feature of ABPA. The crazy paving pattern is seen in pulmonary alveolar proteinosis but can also be seen in mucinous broncho-alveolar carcinoma, exogenous lipoid pneumonia, sarcoidosis, NSIP, pneumocystis pneumonia and several other diffuse acute conditions.
- A CT scan, obtained in a patient with haematuria after minimal trauma, reveals a rim of enhancement surrounding a markedly dilated right renal pelvis and collecting system. Note is made of variable thickness to the enhancing rim and enhancing cortical strands. The report describes it as a rim sign. What is the likely diagnosis?
A. Hydronephrosis
B. Renovascular compromise
C. Diabetes mellitus
D. Pyelonephritis
E. Fractured kidney
- A. Hydronephrosis
A different type of rim sign is seen in association with chronic hydronephrosis. After contrast material is administered, enhancement occurs in the residual, but markedly atrophic, renal parenchyma, surrounding the dilated calices and renal pelvis. Unlike vascular compromise, the thickness of the enhancing rim varies along its length. The inner margin of this hydronephrotic rim is concave towards the renal hilum, and enhancement of the cortical columns between the dilated collecting system elements may be seen. Unopacified urine in the dilated collecting system may produce a negative pyelogram.
@# 22. In the case of a vertebral compression fracture, all the statements regarding imaging findings suggests a malignant cause, except
A. Involvement of the posterior elements
B. Persistent loss of T1W bone marrow signal on sequential imaging
C. Paravertebral soft-tissue component
D. Post-contrast gadolinium enhancement
K. Convex posterior border of the vertebral body
- D. Post contrast gadolinium enhancement
A convex posterior border of the vertebral body is more frequent in metastatic compression fractures than acute osteoporotic compression fractures. A higher frequency of abnormal signal intensity of the pedicle of metastatic fractures is seen in comparison to acute osteoporotic fractures; posterior element involvement is observed more commonly in metastatic compression fractures in comparison to benign fractures. Although epidural mass was suggestive of metastatic fractures, a paraspinal mass is more commonly associated with metastatic compression fracture. Metastatic involvement of other vertebra is also more likely to suggest malignant compression fracture.
Spared normal bone marrow signal intensity of the vertebral body is highly suggestive of acute osteoporotic compression fractures. Band like low signal intensity on T1-weighted and T2-weighted images is more common in acute osteoporotic compression fractures than metastatic compression fractures. Retropulsion of a posterior bone fragment is more frequent in osteoporotic compression fractures than metastatic compression fractures, although multiple fractures are more commonly benign. Post-contrast enhancement is seen in both malignant and benign causes.
@# 23. All of the following are true of toxoplasmosis of AIDS, except
A. It is the most common focal CNS infection.
B. Treatment is started empirically based on imaging.
C. The basal ganglia and cerebral hemispheres are commonly involved.
D. Haemorrhage and calcification are common post-therapy.
F. . A single lesion is the most common.
- E. A single lesion is the most common.
Toxoplasmosis is the most common opportunistic CNS infection in patients with AIDS. Toxoplasmosis typically manifests on CT scans and MRIs as nodular (small-encephalitis) and/or ring-enhancing (large-abscess) lesions within the brain parenchyma. The enhancing ring, when present, may be somewhat thicker and more ill defined than that seen in association with a typical bacterial abscess.
The lesions are associated with surrounding oedema and tend to be multiple at presentation. However, a significant percentage of patients present with solitary lesions. Toxoplasmic lesions are most often seen in the basal ganglia and grey-white interface of the cerebral hemispheres. On non- enhanced Tl weighted MR images, the lesions are of low signal intensity; on T2-weighted MR images, the lesions are mildly to moderately hyperintense in relation to the brain parenchyma and can be difficult to separate from the surrounding oedema. Therapy is often begun empirically as soon as CT scans or MR images show focal parenchymal lesions of any sort because the infection is so common in this population. The presence of small haemorrhages may be a sign of toxoplasmosis, and calcifications can occasionally be seen in treated lesions.
@# 24. On newborn heel stick screening, a newborn infant is found to suffer from congenital hypothyroidism. On ultrasound, the thyroid gland is diffusely enlarged, and on Technetium 99m thyroid scintigraphy there is increased uptake of radioactive tracer within the gland. There is no evidence of ectopic thyroid tissue.
What is the most likely cause for the congenital hypothyroidism?
A. Thyroid hypoplasia
B. Hypothalamic dysfunction
C. Thyroid dyshormonogenesis
D. Maternal antibody induced hypothyroidism
E. Hypopituitarism
- C. Thyroid dyshormonogenesis
Thyroid dysgenesis is the most common cause for congenital hypothyroidism, accounting for up to 85% of cases (causes include ectopy, aplasia and hypoplasia); however in this case, the ultrasound and scintigraphy findings do not suggest this as a cause.
The second most common reason is therefore thyroid dyshormonogenesis, accounting for 10%-15% of cases (also described as thyroid hormone biosynthetic defect, e.g., hereditary Pendred’s syndrome). The remainder of the causes listed are extremely rare.
@# 25. An 8-year-old child with right upper-abdominal pain and a palpable mass was sent for US of the liver. The US showed a large heterogeneous mass occupying at least half of the right lobe of the liver. The rest of the liver was normal in appearance. Which one of the following is the most common benign primary liver tumour in children?
A. Hepatocellular carcinoma
B. Hepatoblastoma
C. Angiosarcoma
D. Infantile haemangioendothelioma
E. Cholangiocarcinoma
- D. Infantile haemangioendothelioma
Although primary hepatic neoplasms represent only a small percentage of solid tumours that occur in children, the finding of focal hepatic lesions in a child is not an uncommon event in a busy radiology practice. The most common neoplasm involving the liver in children, as in adults, is metastatic disease. Most primary liver tumours in children are malignant, but one-third are benign; benign lesions may be of mesenchymal or epithelial origin. The most common benign tumours are, in decreasing order of frequency, infantile haemangioendothelioma, PNH, mesenchymal hamartoma, nodular regenerative hyperplasia (NRH) and hepatocellular adenoma.
@# 26. A 43-year-old woman with history of proteinuria presented to the A&E department with shortness of breath and haemoptysis. Chest X-ray showed diffuse airspace opacities and an HRCT was organised. The HRCT showed diffuse airspace opacities, ground-glass change and confluent consolidation, which was reported as acute diffuse alveolar haemorrhage. Which of the following can be classically expected on CT sinus study?
A. Bilateral frontal mucocoele
B. Unilateral sinusitis involving all the sinuses on one side
C. Chronic destructive sinusitis with nasal perforation
D. Hypoplastic maxillary sinuses
E. Oro-antral fistula
- C. Chronic destructive sinusitis with nasal perforation
Wegener’s granulomatosis is a probable autoimmune disease characterised by systemic necrotising granulomatous destructive angitis, with a classic triad of respiratory tract inflammation, systemic small vessel vasculitis and necrotising glomerulonephritis.
Sinus disease classically includes destructive sinusitis, nasal septal ulceration, septal perforation and saddle nose deformity.
@# 27. A CT scan, obtained to exclude retroperitoneal hematoma in a patient with sustained hypotension for 1 hour after cardiac catheterisation and subsequent cardiac arrest, shows a hypoattenuating renal cortex compared with the medullary enhancement No additional contrast material was given at the time of the CT. Which of the following signs is being described here?
A. Hydronephrotic rim sign
B. Comet tail sign
C. Crescent sign
D. Reverse rim sign
E. Soft-tissue rim sign
- D. Reverse rim sign
The reverse rim sign refers to a hypoattenuating renal cortex visualised at CT, seen against a background of intact medullary perfusion after contrast material is given. This sign also implies severe derangement of cortical blood flow with development of cortical necrosis.
Cortical necrosis may develop as a consequence of obstetric complications, shock from numerous causes, transfusion reaction or other causes of intravascular haemolysis, toxins and rejection in the transplanted kidney.
The comet tail sign refers to pelvic phleboliths
and the soft-tissue rim sign is related to distal ureteric calculus.
The crescent sign refers to the appearance of concentrated contrast material in collecting tubules, arranged parallel to the margin of a dilated calix, which produces a thin line of contrast material at the edge of the calices, resembling a crescent.
@# 28. A report is issued stating that there is a periosteal reaction associated with what the radiologist believes is a benign bony lesion. What type of periosteal reaction is most likely to be associated with a benign lesion?
A. Codman
B. Sunburst
C. Hair-on-end
D. Lamination
E. Buttressing
- E. Buttressing
Periosteal reaction is a sign of new bone formation. Buttressing indicates a slow-growing process with a single, thick layer of periosteum (i.e., a solid periosteal reaction). It is found in conditions such as hypertrophic pulmonary osteoarthropathy, atherosclerosis and benign tumours.
More aggressive, faster-growing lesions can cause an interrupted periosteal reaction; lamination (layering) of the periosteum, Codman’s triangles where new bone formation only occurs at the margins of the tumour, sunburst pattern and hair-on-end (this is seen in lesions that invade bone marrow).
Periosteal reaction is, however, only one of a list of many characteristics of a bone lesion that help determine whether the lesion is biologically active or not.
@# 29. All of the following are associated with tuberous sclerosis, except
A. Giant cell astrocytoma
B. Subependymal hamartomas
C. Pheochromocytoma
D. Cardiac rhabdomyoma
E. Chylothorax
- C. Pheochromocytoma
Tuberous sclerosis is a neuroectodermal disorder, characterised by the classic triad of adenoma sebaceum, seizures and mental retardation. CNS findings include subependymal hamartomas, giant cell astrocytoma (at the foramen of Monro), cortical tubers and heterotopic islands of grey in white matter. Pulmonary involvement include interstitial fibrosis at lung bases, LAM, multiple lung cysts and chylothorax. Cardiac involvement includes rhabdomyoma, aortic aneurysm and congenital cardiomyopathy. Renal involvement includes AML, cysts and RCCs. Ocular lesions include optic nerve glioma and hamartoma. Other visceral abnormalities include splenic tumour, pancreatic and hepatic adenomas.
@# 30. A 22-month-old boy presents with abdominal pain and is found on US to have an intussusception.
Which of the following statements is false with regard to his initial management and treatment?
A. The patient should be reviewed for signs of peritonitis by a paediatric surgeon.
B. Bowel infarct, peritonitis and perforation are potential complications if the intussusception is left untreated.
C. The patient should be fluid resuscitated prior to attempts at air enema reduction.
D. A plain abdominal radiograph should be obtained prior to air enema reduction to rule out signs of perforation.
E. A successful intussusception reduction is noted when air is seen to fill the small bowel loops
- D. A plain abdominal radiograph should be obtained prior to air enema reduction to rule
out signs of perforation.
The traditional role of plain radiography in the evaluation of children suspected to have intussusception is threefold: - When the clinical suspicion is low, the role of plain radiography is to allow exclusion of intussusception and diagnosis of other pathologic processes that are responsible for the patient’s symptoms.
- When the clinical suspicion is high, the role of plain radiography is to allow confirmation of intussusception.
- If intussusception is present, the role of plain radiography is to allow exclusion of intestinal obstruction or perforation.
@# 31. An MRI of the liver with contrast was performed in a 50-year-old woman after a complex mass was identified on US. The mass was reported as suspicious for epithelioid haemangioendothelioma. All of the following are expected features of this lesion, except
A. Vascular origin
B. Female predominance
C. Typical presentation of multifocal nodules
D. Avid arterial phase enhancement
E. Capsular retraction
- D. Avid arterial-phase enhancement
HEH is a low-grade primary malignancy of the hepatic vasculature with an incidence of less than
0.1 per 100,000 in the general population per year. Because its occurrence is so rare, the patient demographics cannot be accurately assessed.
However, demographic data from case review studies indicate an age range of 25-58 years (average 43.5 years) and a slight female predominance (male to female ratio 2:3). Typical manifestations of HEH include non focal abdominal pain, jaundice and hepatosplenomegaly, but HEH has also been discovered incidentally in asymptomatic patients. Budd-Chiari syndrome can develop if the tumour invades the hepatic veins.
Alternating high- and low-signal-intensity rings on T2-weighted and contrast-enhanced T1 weighted images have been characterised as a ‘target’ sign. The tumours typically exhibit central signal hypointensity on unenhanced T1-weighted images and a multilayered target-like appearance with prominent rim like enhancement on contrast-enhanced T1-weighted images.
The presence of capsular retraction in subcapsular hepatic tumours, along with a target-like appearance of the tumours on contrast enhanced CT and MR images, is suggestive but not necessarily indicative of HEH. This constellation of findings can be found in peripheral cholangiocarcinoma, confluent foci of hepatic fibrosis (usually in the setting of advanced cirrhosis), previously treated primary or metastatic HCCs and large atypical cavernous haemangiomas. However, the absence of cirrhosis in a patient with multiple liver masses that coalesce over time to form larger masses, in combination with other characteristic imaging findings of HEH, increases the likelihood of this diagnosis.
- A 37-year-old woman with asthma underwent HRCT of the chest and was diagnosed based on clinical examination, blood tests and HRCT to have Churg-Strauss syndrome or allergic granulomatosis. Which of the following appearances would fit with
the diagnosis?
A. Peripheral predominant lobular consolidation with centrilobular nodules
B. Peripheral predominant homogenous consolidation without centrilobular nodules
C. Peripheral predominant interstitial reticular opacities with underlying traction bronchiectasis
D. Central bronchiectasis and patchy airspace opacities with mucous plugs
E. Upper lobe predominant interstitial pulmonary fibrosis with architectural distortion
- A. Peripheral predominant lobular consolidation with centrilobular nodules.
On thin-section CT, the parenchymal abnormal findings of CSS could be classified into three patterns. The first pattern is subpleural consolidation with lobular distribution. The second pattern is centrilobular perivascular densities, diffusely scattered centrilobular nodules <5 mm in diameter, especially within the ground glass opacity lesion. The third pattern is multiple larger nodules. Bronchial wall thickening, with or without bronchial dilatation, and hyperinflation are likely to be related to asthma. Interlobular septal thickening may reflect the interstitial pulmonary oedema attributed to the cardiac and pericardial involvement.
Peripheral predominant homogenous consolidation is a feature of chronic pulmonary eosinophilia. Nodules arc not a feature of chronic pulmonary eosinophilia. Central bronchiectasis and mucous plugs are a feature of ABPA.
@# 33. Which of the following is incorrect?
A. Spoke wheel sign - Renal oncocytoma
B. Pear-shaped bladder sign - Pelvis lipomatosis
C. Pie-in-the-sky bladder sign - Bilateral psoas hypertrophy
D. Spaghetti sign - Haematuria
E. Balloon-on-a-string sign - Hydronephrosis
- C. Pie-in-the-sky bladder sign Bilateral psoas hypertrophy
The spoked wheel description was applied to the angiographic appearance of the vascular pattern seen in some oncocytomas. Centripetal ‘spoke’ vessels arising from a peripheral ‘rim’ vessel were initially thought to be characteristic of this tumour. However, the pattern is now known to be non-specific, and a similar vascular arrangement has been described with renal cell carcinoma.
The normal round shape of the opacified bladder may assume a pear or tear drop shape when it is symmetrically compressed in the pelvis by an extrinsic process. The differential diagnosis includes pelvic fluid (haematoma, lymphocele, urinoma or abscess), pelvic lipomatosis, vascular dilatation (aneurysm or collateral vessel development), symmetric lymph node enlargement and psoas muscle hypertrophy.
A pie-in-the-sky bladder may be seen with pelvic trauma. The sign refers to the high position of the opacified bladder within the pelvis at imaging and implies the presence of a large pelvic haematoma; it should raise concern for an associated urethral injury.
A linear filling defect within the bladder may result from extrusion of a blood clot from the ureter, which has acted as a mould, in gross haematuria. This spaghetti sign implies that the bleeding source is above the bladder.
Balloon-on-a-string sign refers to the appearance of a high and somewhat eccentric exit point of the ureter from a dilated renal pelvis and is a typical finding of ureteropelvic junction obstruction.
@# 34. A young adult man presents with a painful left wrist following a fall from height. A lateral view of the wrist shows loss of co linearity of the radius/lunate/capitate axis with the capitate displaced dorsally. What injury is this constellation of findings compatible with?
A. Midcarpal dislocation
B. Perilunate dislocation
C. Lunate dislocation
D. Volar intercalated segmental instability
E. Dorsal intercalated segmental instability
- B. Perilunate dislocation
Lunate and perilunate dislocations and fracture dislocations may be easily overlooked on plain films and should be actively sought and excluded given an appropriate clinical history.
On the AP view, the lines along the proximal poles of both the proximal and distal carpal rows should be
smooth and uninterrupted.
The lunate should appear trapezoid and not triangular in shape (AP radiograph), which may indicate dislocation and rotation.
On the lateral view, the distal radius, lunate and capitate should be in alignment.
Volar loss of lunate alignment is seen in lunate dislocation,
and dorsal loss of capitate alignment is seen in perilunate dislocation.
In addition, the scapholunate (normal 30-60 degrees)
and the capitolunate (normal 0-30 degrees) should be assessed for evidence of intercalated segmental instability.
@# 35. All the following are true of venous angioma, except
A. It can be considered normal.
B. It contains small arterial channels.
C. It is associated with cavernomas.
D. It shows a spoked wheel configuration on imaging.
E. It normally has a large draining vein but no feeding arteries.
- B. It contains small arterial channels
Developmental venous anomalies (DVAs), also called venous angiomas, are variations of the normal veins that are necessary for the drainage of white and grey matter. They are associated with other vascular malformations like cavernoma. On contrast-enhanced CT, the venous collector of the DVA is readily detectable as a linear or curvilinear focus of enhancement, typically coursing from the deep white matter to a cortical or a deep vein or to the dural sinus. On MRI, DVAs typically have a trans-hemispheric flow void, on both T1-weighted and T2-weighted images. The collector vein is detected as a linear or small, round, signal-void structure on all sequences and is shown most clearly on T2 weighted imaging. On contrast-enhanced MRI, the cluster of veins in DVAs has a spoked wheel appearance; the veins are small at the periphery and gradually enlarge as they approach a central draining vein. This appearance has been referred to as caput medusae (or the ‘head of Medusa’).
@# 36. A 5-year old boy, who underwent a bone marrow transplantation 1 week earlier for an underlying haematological malignancy, presents with shortness of breath, cough and chest tightness.
Which of the following complications would be least likely?
A. Lymphoid interstitial pneumonitis
B. Pulmonary oedema
C. Pulmonary embolism
D. Infective interstitial pneumonitis from CMV
E. Idiopathic interstitial pneumonitis
- A. Lymphoid interstitial pneumonitis
Early complications complications that occur at any point from the time of transplantation to the end of the early post-engraftment period - include interstitial pneumonitis (infective and non- infective types), infection, oedema, haemorrhage, thromboembolism and calcification. Bronchiolitis obliterans with organising pneumonia (BOOP) is a rare complication that may occur during the early or late post-engraftment period.
Late pulmonary complications - complications that occur more than 100 days after engraftment - include chronic GVH disease, infections, bronchiolitis obliterans, fibrosis and lymphoid interstitial pneumonitis.
@# 37. A 56-year-old woman presented to her GP with pain and palpable mass in the right upper quadrant. She was sent for US, which showed a large heterogeneous mass in the right lobe of the liver. A contrast-enhanced MRI of the liver is urgently organised for further characterisation. The lesion is reported as consistent with fibrolamellar carcinoma.
All of the following are expected findings, except
A. Central scar low on T1W and T2W images.
B. Solitary mass is the usual presentation.
C. Favorable prognosis.
I). Rare pathological subtype of hepatocellular carcinoma.
E. Background cirrhotic change to the liver parenchyma.
- E. Background cirrhotic change to the liver parenchyma
Fibrolamellar HCC is a rare hepatic neoplasm that accounts for less than 1% of HCC in the United States. This tumour has unique clinicopathological features that are significantly different compared with conventional HCC.
Fibrolamellar HCC predominantly occurs in young individuals.
On MRI, fibrolamellar HCC is usually hypointense on T1-weighted images and hyperintense on T2 weighted images.
The fibrous central scar is typically hypointense on both Tl weighted and T2-weighted images. This feature can help to distinguish fibrolamellar HCC from FNH because the central scar in the latter is predominantly T2 hyperintense.
The presence of intralesional fat has not been reported in fibrolamellar HCC. Calcification may be difficult to identify on MRI.
Gadolinium contrast enhancement characteristics of fibrolamellar HCC mimic the patterns seen on CT showing marked heterogeneous contrast enhancement on the arterial phase and becoming isointense or hypointense on the portal venous and delayed phase.
Some authors have reported that fibrolamellar HCC does not retain hepatobiliary-specific contrast agents, such as gadoxetate disodium and gadobenate dimeglumine, on the hepatobiliary phase, which potentially may be useful in differentiating fibrolamellar HCC from FNH.
@# 38. A 37-year-old woman involved in a frontal car collision and collapse at the scene of incident was brought to the A&E department and sent for an emergency whole-body CT. All of the following are correct regarding blunt cardiac trauma, except
A. Cardiac concussion results in abnormal cardiac enzymes.
B. Traumatic pericardial rupture resulting from blunt chest trauma is rare.
C. Cardiac herniation is a serious complication of pericardial rupture.
D. Traumatic ventricular septal defects affect the muscular portion.
E. Myocardial contusion is associated with cardiac tamponade.
- A. Cardiac concussion results in abnormal cardiac enzymes.
Blunt cardiac injury (BCI) is the most common type of cardiac injury after blunt thoracic trauma. In cardiac concussion, the mildest form of cardiac injury, there is no myocardial cell damage or elevated enzyme levels. Cardiac contusion can present as bilateral cardiogenic pulmonary oedema and elevated cardiac enzymes. Echocardiography shows increased myocardial echogenicity and focal systolic hypokinesia, and it is useful in diagnosing other traumatic cardiac injuries that are commonly associated with myocardial contusion, such as pericardial effusion, tamponade, traumatic ventricular septal defect and valvular injury. Typically, traumatic ventricular septal defects occur in the muscular portion of the interventricular septum, near the cardiac apex.
Haemopericardium is commonly associated with cardiac rupture. Tamponade resulting from ventricular rupture is often fatal; however, bleeding from lower pressure atria may be survivable. Besides cardiac chamber rupture, traumatic haemopericardium may also result from aortic root injury, myocardial contusion and coronary artery laceration.
Traumatic pericardial rupture resulting from blunt chest trauma is rare. Tearing may involve either the pleuropericardium or the diaphragmatic pericardium. Cardiac herniation is a serious complication of pericardial rupture.
@# 39. An 88-year-old man with obstructive uropathy and hard nodular prostate gland on digital rectal examination was being further investigated for his prostate cancer. Which one of the following magnetic resonance spectroscopic imaging metabolic peaks is expected in a patient with prostate cancer?
A. High citrate peak, low choline/creatine peak
B. High citrate peak, high choline/creatine peak
C. Low citrate peak, high choline/creatine peak
D. Low citrate peak, low choline/creatine peak
E. Low citrate peak, normal choline/creatine peak
- C. Low citrate peak, high choline/creatine peak
MRS is a modality that provides information about the cellular metabolites within the prostate gland; it displays the relative concentrations of key chemical constituents, such as citrate, choline and creatine. The normal prostate gland contains low levels of choline and high levels of citrate, whereas prostate cancers have increased levels of choline and decreased levels of citrate. The high choline levels in prostate tumours are related to increased cell turnover. In prostate cancers, the levels of zinc in secretary epithelial cells are lower, which eventually leads to diminished amounts of citrate. Thus, the ratio of choline to citrate is an index of malignancy. The ratio of choline (Cho) plus creatine (Cr) to citrate (Cit) ([Cho + Cr]/Cit) has been widely studied and cut-off values have been suggested for detection of cancer.
Besides analysis of choline, citrate and creatine content, newer image acquisition and analysis software may enable evaluation of other metabolites, such as polyamine peaks, which have also been associated with prostate cancers. MR spectroscopy of tissue samples revealed that levels of polyamines (putrescine and spermine) were reduced in prostate cancer compared with the levels in benign tissue.
@# 40. A 42-year old woman with knee joint stiffness, pain and reduced mobility is investigated with a plain X-ray, which reveals extensive soft-tissue swelling around the joint with
large periarticular erosions. There is no evidence of calcification and bone density is maintained. MRI shows low-signal foci within the soft-tissue mass. What is the likely diagnosis?
A. Pigmented villonodular synovitis
B. Haemophilia
C. Synovial sarcoma
D. Behcet’s syndrome
E. Psoriatic arthropathy
- A. Pigmented villonodular synovitis.
Radiographs may be normal or may reveal periarticular soft-tissue swelling. Visible calcifications are extremely unusual. The joint space is normal in width until late in the course of the disease, and juxta-articular osteoporosis is absent or mild. Bone erosions with sclerotic margins may be present on both sides of the affected joints, particularly in joints with a tight capsule, such as the hip. On MRI, the synovial lesions have low to intermediate signal intensity relative to that of muscle on T1 weighted images and low signal intensity on T2-weighted images, caused by the magnetic susceptibility effect produced by haemosiderin at the periphery of the lesions.
The ‘black synovium’ appearance can also be seen with amyloid deposition or recurrent intra- articular bleeding (e.g., in haemophiliac arthropathy).
Synovial sarcoma presents as a solitary calcified mass outside the joint.
@# 41. A 40-year-old woman with progressive difficulty in walking and difficulty in holding objects reveals a large burn over the dorsum of her right hand on clinical examination. Sagittal MRI of the cervical spine shows a long segment lesion in the cervical and upper thoracic spinal cord with low signal on T1W images and high signal on T2W images without
any change on post-contrast images. What is the diagnosis?
A. Ependymoma
B. Syringomyelia
C. Astrocytoma
D. Haemangioblastoma
E. AVM
- B. Syringomyelia
Syringomyelia refers to any cavity within the substance of the spinal cord that may communicate with the central canal, usually extending over several vertebral segments. MRI shows a cystic area with low signal on T1-weighted and increased signal intensity on T2-weighted images. CSF flow void (low signal on T2-weighted images) is often seen in the cavity from pulsation. The cord may show’ enlargement.
Post-traumatic, post-inflammatory or idiopathic syringomyelia show no abnormal contrast enhancement post-administration of gadolinium. Tumour-associated syrinx may show abnormal enhancement.
@# 42. A chest CT is performed on a 10-year-old boy with known underlying chronic lung changes. Current imaging demonstrates laevocardia with areas of air trapping, bronchial dilatation and bronchial wall thickening, which were also present on previous imaging from 1 year earlier. There are no significantly enlarged mediastinal lymph nodes.
Which of the following differential diagnoses would be least likely to account for the underlying changes?
A. Cystic fibrosis
B. IgA deficiency
C. Juvenile dermatomyositis
D. Primary ciliary dyskinesia
E. Recurrent pneumonias
- C. Juvenile dermatomyositis
All other options would cause bronchiectasis, apart from juvenile dermatomyositis (JDM). JDM is a multisystem autoimmune disease of unknown aetiology that results from inflammation of the small vessels of the muscles, skin, gastrointestinal tract and other organs. It accounts for 85% of cases of paediatric inflammatory myopathy. JDM affects children with an incidence of two or three cases per million children per year. Clinical characteristics of JDM include symmetric proximal muscle weakness, inflammatory cutaneous lesions and Gottron papules (erythematous scaly lesions over the metacarpophalangeal and/or interphalangeal joints), heliotrope (violaceous hue over the eyelids), periorbital oedema, malar erythema, periungual telangiectasia and erythematous scaly rashes over the neck, upper back and extensor surfaces of the extremities.
- A 10-year-old boy falls while running for the school bus and hurts his arm. An X-ray demonstrates a fracture through the proximal humeral diaphysis through a ‘bony lesion*. What is the most likely underlying predisposing bone pathology?
A. Giant cell tumour
B. Osteosarcoma
C. Simple bone cyst
D. Eosinophilic granuloma
E. Ewing’s sarcoma
- C. Simple bone cyst
Simple bone cysts constitute 5% of primary bone lesions with unknown aetiology and consist of cysts filled with yellowish fluid lined by fibrous tissue (rather than epithelial cells; hence some dispute the term true cyst).
They arc most commonly seen at the proximal humerus and femur; other sites include the fibula, calcaneus, talus and rarer sites like the ribs, hands and feet. They are metaphyseal, intramedullary and central in location (rather than eccentric like ABC). They are close to the epiphysis in the growth phase and migrate to the diaphysis with growth. They do not cross the epiphyseal plate, have a thin sclerotic rim, can cause endosteal scalloping and demonstrate the ‘fallen fragment sign’ when complicated by pathological fracture.
@# 44. A 43-year-old woman with known diagnosis of tuberous sclerosis presented to her GP with increasing right upper-abdominal pain. Although the LFT was normal, the GP organised a liver MR in search of angiomyolipomas in the liver. All of the following arc MR features of angiomyolipomas of the liver, except
A. A well-defined mass.
B. Moderately hyperintense signal intensity on T1W images.
C. Moderately hyperintense signal intensity on T2W images.
D. Loss of signal on fat-suppressed sequences.
E. Usually shows late arterial enhancement on the post-contrast sequence.
- E. Usually shows late arterial enhancement on the post-contrast sequence.
Angiomyolipoma (AML) is a benign, unencapsulated mesenchymal tumour that is composed of
varying proportions of three elements: smooth muscle cells, thick-walled blood vessels and mature adipose tissue. AML occurs more commonly in the kidneys; hepatic involvement is rare. In contrast to renal AML, which is associated with tuberous sclerosis in 20% of patients, hepatic AML is associated with tuberous sclerosis in only 6%. AML can be histologically classified on the basis of fat content into mixed, lipomatous (70% fat), myomatous (10% fat) and angiomatous types. US, CT and MR imaging typically demonstrate the fat component and prominent central vessels. At US, AML may be highly echogenic and is then indistinguishable from haemangiomas.
Frequently, AML has a high fat content, with high signal intensity on T1-weighted images and a significant drop in signal intensity on fat-suppressed images.
AML demonstrates early intense contrast enhancement that peaks later than that of a HCC. Dynamic contrast-enhanced CT or MR images obtained during the early phase of enhancement may be useful in discriminating between AML and fat-containing HCC. The fatty areas of AMLs are well vascularised and enhance early, whereas steatotic foci in HCC are relatively avascular and have less contrast enhancement. However, unlike renal AML, 50% of hepatic AMLs lack considerable fat content. Because of this variable fat content, it is difficult to accurately distinguish AML from other hepatic tumours.
@# 45. With regard to the progression of pulmonary consolidation on CXR, all of the following options are true except
A. Lung contusion appears in 6 hours and clears in 3-7 days.
B. Aspiration appears in minutes and clears in 24-48 hours unless infected.
C. Lung infarction due to pulmonary embolism manifests after 3-5 days and clears in approximately 3 weeks.
D. Fat embolism appears in 6 hours and clears in 7-10 days.
E. ARDS with difFuse alveolar damage appears after 24-48 hours and clears in 4-6 weeks.
- D. Fat embolism appears in 6 hours and clears in 7-10 days.
Lung contusion turns out to be the most common manifestation of blunt trauma to the chest. Contusions become visible on chest radiographs within 6 hours post-trauma and resolve within 3-7 days. Massive contusion can lead to pulmonary oedema and diffuse alveolar damage (DAD).
Aspiration appears within minutes and clears in 24-48 hours unless it triggers an infection with subsequent pneumonia.
Pneumonia appears after 5-7 days and clears in 2-4 weeks.
Lung infarction due to pulmonary embolism manifests after 3-5 days and clears in approximately 3 weeks.
Fat embolism appears after 24-48 hours and clears in 7-10 days.
ARDS with diffuse alveolar damage appears after 24-48 hours and dears in 4-6 weeks.
@# 46. An 88-year-old man with obstructive uropathy and hard nodular prostate gland on digital rectal examination is being further investigated for his prostate cancer. lie has been scheduled for a staging MRI of the prostate. Which one of the following is the characteristic imaging finding of prostate cancer on DWI?
A. High on DWT, low on ADC and corresponding low signal intensity on T2W MRI
B. Low on DWI, high on ADC and corresponding low signal intensity on T2W MRI
C. High on DWI, low on ADC and corresponding high signal intensity on T2W MRI
D. Low on DWI, high on ADC and corresponding high signal intensity on T2W MRI
E. High on DWI, low on ADC and corresponding normal signal intensity on T2W MRI
- A. High on DWI, low on ADC and corresponding low signal intensity on T2W MRI
T2-weighted images are the ‘workhorse’ images for prostate cancer. The glandular peripheral
zone appears high in signal, whereas the central stroma has lower signal intensity on T2-weighted images. Tumours are lower in signal intensity than normal peripheral zone glandular tissue on T2-weighted images. Peripheral zone cancers are usually round or ill-defined. Various conditions, such as prostatitis, haemorrhage, atrophy, benign prostatic hyperplasia (BPH) and post-treatment changes can mimic cancer. Cancers in the central gland are even more challenging to detect than peripheral zone cancers, because the signal characteristics of the normal and hypertrophic central gland arc usually similar to those of the tumour on T2-weighted images. Prostate cancers often include tightly packed glandular elements with increased cellular density and diminished extracellular spaces, which can be detected as high-signal-intensity foci on raw DW MRI (restricted diffusion) but are low in signal on apparent diffusion coefficient (ADC) maps. ADC maps reflect the amount of diffusion present - the lower the diffusion, the darker the lesion.
@# 47. A 50-year-old patient presents with shortness of breath to his GP. Following abnormalities on the chest radiograph, a CT is performed, demonstrating bilateral hilar and right paratracheal lymphadenopathy along with coarse reticulations and nodular thickening along the fissures and bronchovascular bundles. Elevated ACE serum levels are noted.
What is not a typical musculoskeletal manifestation of this disease?
A. Lacy lytic lesions in the phalanges of the hands
B. Polyarthralgia with tenosynovitis
C. Multiple bony lesions with high T2W and intermediate T1W signal characteristics
D. Soft-tissue calcifications
E. Dactylitis
- D. Soft tissue calcifications
Acute arthritis may be the first manifestation of sarcoidosis. It is mainly oligoarticular but occasionally polyarticular, and rarely monoarticular. Ankles are the most commonly involved joints. Enthesitis, tendinosis and tenosynovitis are well recognised, especially around the ankle. The triad of acute arthritis, bilateral hilar adenopathy and erythema nodosum is known as Lofgren syndrome. Chronic arthritis tends to involve the shoulders, hands, wrists, ankles and knees. Dactylitis can be seen; it is very similar to that seen in patients with psoriatic arthritis.
Osseous involvement causes cystic, reticular or destructive lesions involving mainly the hands and feet (lace-like pattern) but can affect the skull, ribs, sternum, vertebrae, nasal bones, pelvis, tibia and femur as well. MRI shows multiple bony lesions with high T2-weighted and intermediate T1-weighted signal, although diffuse involvement is also recognised. Sarcoid myopathy can also he acute and mimic polymyositis.
- An infant boy was investigated with MRI for seizures. The left side of the brain is smaller than the right and there is evidence of T2 hypointensity on the gyri. There is diffuse contrast enhancement adjacent to the gyri and sulci on the same side. Some enhancement is also noted along the ipsilateral posterior globe. Which of the following is the most likely diagnosis?
A. Hypoxic ischaemic encephalopathy
B. Meningitis
C. Sturge-Weber syndrome
D. Gliomatosis cerebri
E. Tuberous sclerosis
- C. Sturge-Weber syndrome
Sturge-Weber syndrome is a rare neurocutaneous disorder characterised by abnormal vascular malformation involving the skin (ophthalmic branch of the trigeminal nerve) and leptomeninges of the brain. The facial capillary port-wine stain is usually ipsilateral to the leptomeningeal venous angiomatosis. Tram-track cortical calcification (T2 hypointensity) and cortical atrophy is probably secondary to underlying ischaemia. Associated calvarial thickening, enlarging diploic space and increased pneumatisation of mastoid air cells (Dyke Davidoff-Mason Syndrome) and ipsilateral enlargement of choroid plexus may also be seen. Angioma of the choroid of the eye is also a characteristic finding.
