TEST PAPER 3 Flashcards
1.A 77-year-old man presents with a progressively enlarging pulsatile mass in the leftgroin corresponding to the puncture site of a previous coronary angiography.
Urgent outpatient ultrasound shows a large anechoic lesion with peripheral filling defectand arterial pattern intraluminal flow. What is most appropriate management plan?
A. Covered stent
B. Ultrasound-guided compression
C. Ultrasound-guided thrombin injection
D. Open surgery
E. CT angiogram first for treatment planning
1.C. Ultrasound-guided thrombin injection
Pseudoaneurysms are common vascular abnormalities that represent a disruption in arterial wallcontinuity.
Surgical repair was the treatment of choice for superficial extremity pseudoaneurysms untilUS-guided compression was introduced. US-guided percutaneous thrombin injection has replaced US-guided compression as the therapeutic method of choice for treatment of post catheterisation pseudoaneurysms. Endovascular techniques like stent placement (indispensable artery) or embolisation (dispensable artery) have a lower complication rate in the treatment of visceral pseudoaneurysms than does surgical management.
@# 2.All of the following are associations of Chiari II malformation, except
A. Dysgenesis of corpus callosum
B. Klippel-Feil deformity
C. Syringomyelia
D. Meningomyelocele
E. Tectal beaking
2.B. Klippel-Feil deformity
The hallmarks of Chiari II malformation include caudally displaced fourth ventricle (the fourthventricle is in normal position in Chiari 1 malformation), caudally displaced brain stem, and tonsillar or vermian herniation through the foramen magnum.
Associations include lumbar myelomeningocele, syringohydromyelia, dysgenesis of the corpus callosum, obstructive hydrocephalus, absent septum pellucidum and excess cortical gyration.
It is not associated with any of the bony abnormalities described in Chiari I malformation, like basilar impression, occipitalization of the atlas, platybasia and Klippel-Feil anomaly.
3.A 17-year-old girl is newly diagnosed with Crohn’s disease and an MR enterography has beenrequested for evaluation of the disease extent and distribution. All of the following arc latefindings of Crohn’s disease on MRE, except
A. Fistulae
B.Skip lesions
C. Strictures
D. Small bowel obstruction
E. Ulcers
3.E. Ulcers
At pathologic analysis, active inflammation is characterised by varying degrees of neutrophiliccrypt injury. In mildly active Crohn’s disease, a small fraction of crypts arc infiltrated by neutrophils (cryptitis), with associated crypt destruction and mucin depletion.
As the degree of activity increases, there is a corresponding increase in the proportion of involved crypts and the severity of crypt injury, including crypt epithelial necrosis, intraluminal exudates (crypt abscess), and eventual ulcer formation. Two types of ulcers are seen in Crohn’s disease: superficial aphthous ulcers and deep fissuring ulcers. Deep fissuring ulcers are more problematic than superficial aphthous ulcers; they break through the mucosa and into the deeper layers of the bowel wall, initially resulting in submucosal inflammation and oedema. Some investigators have reported that deep ulcers may be seen in MR enterography, whereas superficial ulcers defy detection.
4.A 76-year-old woman with one previous history of admission in the medical ward withacute renal failure 6 years ago has now been referred to the radiology department for aCT angiography of the lower limb arteries subject to symptoms of claudication. Therenal team were again involved when she developed acute worsening of renal functionafter the CT study. All the following are features of contrast-induced nephropathy,except
A. Alternative major insults to kidneys ruled out.
B.Increase in serum level of creatinine of 0.5 mg/dL.
C. Rise in serum creatinine level by >50% above baseline.
D. Increase in serum creatinine occurs 48-72 hours after administration of contrast.
E. Raised serum creatinine persists for 2-5 days.
- C. Rise in serum creatinine level by >50% above baseline.
Diagnosis of CIN (contrast-induced nephropathy) is most often based on an increase in the serum level of creatinine after exposure to a contrast agent. Diagnostic criteria for CIN include exposure to contrast agent, increase in serum level of creatinine of 0.5 mg/dL or 25% greater than baseline, increase in serum level of creatinine occurring 48-72 hours after administration of contrast agent and persisting for 2-5 days, and alternative major injuries being ruled out.
@# 5. Skeletal survey is indicated as an investigation for all of the following, except
A. Eosinophilic granuloma
B. Multiple myeloma
C. Non-accidental injury
D. Skeletal metastasis
E. Suspected skeletal dysplasia
- D. Skeletal metastasis
Eosinophilic granuloma is associated with Langerhans cell histiocytosis and is an indication for a skeletal survey, along with multiple myeloma and non-accidental injury. Skeletal surveys are never performed for skeletal metastasis.
Radiological evaluation of skeletal dysplasia often starts with a skeletal survey for several non-lethal skeletal dysplasia.
- A central mass with homogeneous signal intensity is identified on MRI in the fourth ventricle of a 4-year-old child. Which of the following is the most likely diagnosis?
A. Astrocytoma
B. Medulloblastoma
C. Ependymoma
D. Pontine glioma
E. Tectal plate glioma
- B. Medulloblastoma
Medulloblastoma is the most common infratentorial paediatric brain tumour. It typically presents as a midline, non-calcified solid vcrmal mass, obstructing the fourth ventricle.
Classic medulloblastoma typically arises from the roof of the fourth ventricle and is midline in location in 75% 90% of cases. Classic medulloblastoma is a highly cellular, densely packed tumour, which is reflected on imaging; it appears hyperdense relative to brain on CT (89% of cases) and shows restricted diffusion on DWI. This feature of medulloblastoma allows differentiation from JPA, ependymoma and brainstem glioma. Almost all medulloblastomas enhance post-contrast; the degree of enhancement varies from diffuse homogenous to heterogeneous.
- A young woman with positional headache shows a well-defined round mass at the anterior margin of the third ventricle with high signal on both T1W and T2W images. Asymmetrical lateral ventricular enlargement is evident. What is the diagnosis?
A. Colloid cyst
B. Choroid plexus cyst
C. Porencephalic cyst
D. ACA aneurysm
E. Haemorrhagic contusion
- A. Colloid cyst
The most common true mass of the foramen of Monro is a colloid cyst, a benign lesion that occurs in adult patients. This well defined round cyst may be from several millimeters to 3 cm in size and attaches to the anterior superior aspect of the third ventricle roof. Often hyperattenuating at non-enhanced CT, it has variable signal intensity at MR imaging and is often hyperintense on T1-weighted and FLAIR images. Peripheral gadolinium enhancement is rarely seen. Ninety percent of colloid cysts are asymptomatic and stable, whereas 10% are reported to enlarge or cause hydrocephalus. Rapid enlargement has been associated with coma and death.
- A CT scan of a 25-year old woman on OCP shows a focal area of low attenuation that demonstrates homogenous enhancement in the arterial phase with rapid washout on the portal venous and delayed phases. She presents a week later with an acute abdomen and hemodynamic instability. What is the most appropriate management?
A. Gel foam embolisation
B. Liver resection
C. Conservative management
D. Coil embolisation
E. Radiofrequency ablation
- D. Coil embolisation
Ruptured hepatic adenoma is a clinical emergency. Many adenomas are first diagnosed in symptomatic patients presenting with acute abdominal pain, hemodynamic instability, or other signs of rupture, most of whom are on OCP. The gold standard has been to perform emergency laparotomy with gauze packing or partial liver resection. Laparoscopic resection is also possible in theory, but it is technically difficult. Recently, less invasive procedures such as transarterial embolisation have been developed that may also lead to adequate haemostasis without the need for urgent laparotomy, and they are considered the first treatment option. RFA is used in non-ruptured adenomas and its use after haemorrhage may be irrelevant.
@# 9. A 43-year-old woman currently on treatment for Crohn’s disease needs to have her medication reviewed following the recommendation of the MDT. The gastroenterologist wants to perform a CT enterography to assess her disease status and response to treatment prior to the medication review. Which one of the following CT signs suggests inactive Crohn’s disease?
A. Increased mesenteric fat attenuation
B. Mesenteric fibro-fatty proliferation
C. Target sign
D. A non-enhancing thickened bowel wall
E. Comb sign
- B. Mesenteric fibro-fatty proliferation
The main diagnostic purpose of CT enterography in the setting of Crohn’s disease is to differentiate active inflammatory strictures from fibrotic strictures in order to guide therapy.
CT features of active Crohn’s disease include mucosal hyperenhancement, wall thickening (thickness >3 mm), mural stratification with a prominent vasa recta (comb sign) and mesenteric fat stranding, all of which are exquisitely demonstrated at CT enterography.
The capability of CT enterography to depict extra-enteric disease allows the simultaneous diagnosis of complications associated with Crohn’s disease, such as obstruction, sinus tract, fistula and abscess formation.
Mural enhancement is the most sensitive indicator of active Crohn’s disease.
Care should be taken to compare bowel loops with similar distention, since both the jejunum and normal collapsed loops may demonstrate regions of higher attenuation, simulating enhancement.
Inadequately distended bowel loops may be difficult to assess, and secondary signs of active disease, such as mesenteric fat stranding, vasa recta prominence or complications such as fistulas and abscesses should be sought to maximise the accuracy of a diagnosis of active disease.
Prominence of the vasa recta adjacent to the inflamed loop of bowel (comb sign), along with increased mesenteric fat attenuation, is (he most specific CT feature of active Crohn’s disease.
Findings that might be seen in inactive long standing Crohn’s disease include submucosal fat deposition, pseudosacculation, surrounding fibro-fatty proliferation and fibrotic strictures.
- A 36-year-old woman with small cystic lesions identified in the liver when she had an ultrasound assessment a year ago underwent a CT urogram for renal colic. The CT urogram revealed speckled calcification in the medulla of both kidneys. Review of an old IVU showed a striated nephrogram and filling defects in the proximal right ureter. What is the most likely diagnosis?
A. Hyperparathyroidism
B. Medullary sponge kidney
C. Medullary cystic disease
D. Acquired renal cystic disease
E. PCKD
- B. Medullary sponge kidney
Medullary sponge kidney involves dysplastic dilatation of medullary and papillary collecting ducts. It is known to be associated with Ehlers-Danlos syndrome, parathyroid adenoma and Caroli’s disease. Recognised features include medullary nephrocalcinosis, ‘bunch of flower appearance’ and dense, striated nephrogram; it can affect a single kidney (25%) or single pyramids.
Note that papillary blush on IVU without dense streaks is a normal variant, especially when not associated with nephrocalcinosis.
@# 11. A 30-year-old woman is struck over the right cheek during an altercation with another woman. There is bruising and swelling, and a fracture is suspected. What view is the best for demonstrating a zygomatic arch fracture?
A. Townes view
B. Submentovertex view
C. Swimmer’s view
D. Occipitomental view 45 degrees
E. Occipitomental view 30 degrees
- B. Submentovertex view’
The submentovertex (SMV) view, also called the bucket-handle view, shows fractures of the zygomatic arch best.
Townes and occipitomental views are for skull and facial bone fractures.
Swimmer’s view is for viewing the cervico-thoracic junction
- A 1 -year-old infant is admitted with acute stridor. A viral cause is suspected. On AP chest radiography no foreign body is identified, but there is an inverted V appearance of the subglottic trachea. Which of the following is the most likely diagnosis?
A. Foreign body
B. Acute laryngotracheobronchitis
C. Whooping cough
D. Tracheobronchomalacia
E. Epiglottitis
- B. Acute laryngotracheobronchitis
Croup (laryngotracheobronchitis) most commonly affects children between 6 months and 3 years and presents with acute stridor, usually following viral infection. A subglottic inverted V sign is seen on plain film, but the epiglottis and aryepiglottic folds are usually normal.
In contrast, epiglottitis is a life-threatening condition affecting 3-6-year-olds, with a lateral soft-tissue neck radiograph showing thickening of the epiglottis and aryepiglottic folds described as the ‘thumb sign’.
@# 13. When can you see the radiographic changes of fat embolism on a chest X-ray?
- A. No Yes No
The chest radiographic appearance of fat embolism syndrome is non specific. Normal radiographs can also be seen. Most patients presenting with a normal initial radiograph develop radiographic- evident abnormalities within 72 hours of injury, and most cases show radiographic resolution within 2 weeks of hospitalisation.
- A 46-year old woman with constant headache undergoes a CT brain for preliminary evaluation. CT brain reveals a suprasellar solid cystic lesion with some calcification.
MRI confirms the suprasellar mass with high signal in both T1W and T2W images. Marginal enhancement of the peripheral solid rim portion of the lesion is also noted.
What is the diagnosis?
A. Craniopharyngioma
B. Pituitary adenoma
C. Pineoblastoma
D. Meningioma
E. Dermoid cyst
- A. Craniopharyngioma
Craniopharyngiomas account for about 3% of all primary intracranial tumours. Two types of craniopharyngiomas have been described: a childhood type, with frequent occurrence of cyst formation and calcifications and generally a poor prognosis, and an adult type, generally without calcifications or cyst formation and generally a good prognosis.
The cystic areas may be iso-, hyper- or hypointense relative to brain tissue with T1 -weighted sequences. The short T1 relaxation times are the result of very high protein content. With T2-weighted sequences, both the cystic and solid components tend to have high signal intensity. After the administration of contrast material, the solid portions enhance heterogeneously. The thin walls of the cystic areas nearly always enhance. The characteristic calcifications in paediatric craniopharyngiomas may not be discernible, although gradient-echo images may show susceptibility effects from calcified components. Occasionally, craniopharyngiomas are predominantly solid, typically without calcification.
@# 15. A 53-year-old woman with a long-standing history of known Crohn’s disease is referred for a CT enterography for assessment of disease status. Which one of the following statements regarding the CT evaluation of Crohn’s disease is true?
A. Perianal disease is uncommon
B. A thickened hyperenhancing bowel wall is a sign of active disease
C. Mural stratification implies perforation in the bowel wall
D. The comb sign is a specific sign
E. Perienteric stranding is a specific sign
- B. A thickened hyperenhancing bowel wall is a sign of active disease.
The main diagnostic purpose of CT enterography in the setting of Crohn’s disease is to differentiate active inflammatory strictures from fibrotic strictures in order to guide therapy.
CT features of active Crohn’s disease include mucosal hyperenhancement, wall thickening (thickness >3 mm), mural stratification with a prominent vasa recta (comb sign) and mesenteric fat stranding, all of which are exquisitely demonstrated at CT enterography.
The capability of CT enterography to depict extra-enteric disease allows the simultaneous diagnosis of complications associated with Crohn’s disease, such as obstruction, sinus tract, fistula and abscess formation.
Mural enhancement is the most sensitive indicator of active Crohn’s disease.
The term mural stratification denotes the visualisation of bowel wall layers at CT. At CT enterography, the oedematous bowel wall has a trilaminar appearance, with enhanced outer serosal and inner mucosal layers and an interposed submucosal layer of lower attenuation. However, this feature is not specific to Crohn’s disease; it is seen also in other inflammatory bowel diseases and even in some cases of bowel ischaemia.
Prominence of the vasa recta adjacent to the inflamed loop of bowel (comb sign) along with increased mesenteric fat attenuation, is the most specific CT feature of active Crohn’s disease.
Findings that might be seen in inactive long standing Crohn’s disease include submucosal fat deposition, pseudosacculation, surrounding fibro-fatty proliferation and fibrotic strictures.
Perianal disease is common in Crohn’s disease.
@#1 16. A young woman with polycystic ovarian disease is currently under the transplant team, being reviewed and worked up for potential renal transplantation. Regarding renal transplantation, all of the following are true, except
A. US kidney, CT angiography and plain abdominal film provide similar information to MR angiography and MR urography.
B. Pelvicalyceal duplication precludes kidney donation.
C. Twenty percent of kidneys have accessory arterial supply.
D. Right kidney is placed in the left iliac fossa because it is easier technically.
E. Carrel patch is used only for cadaveric kidney.
- B. Pelvicalyceal duplication precludes kidney donation.
The aims of preoperative evaluation of living related donors are to show that the donor will retain a normal kidney after unilateral nephrectomy, to demonstrate that the kidney to be transplanted has no major abnormality, and to outline the vascular anatomy.
US assesses the parenchyma, CT angiogram shows the arterial and venous anatomy, and the plain film demonstrates the pelvicalyceal system. MR angiography and MR urography provide similar information.
Conditions that do not preclude donation include pelvicalyceal duplication, solitary renal cyst, unilateral mild reflux nephropathy and only one scar.
In the case of unilateral duplication, the contralateral kidney is donated.
Twenty percent of kidneys have accessory arterial supply.
Kidneys with multiple arterial supply are more likely to have vascular complications.
The transplanted kidney is placed extraperitoneally in the iliac fossa; usually the right kidney is placed in the left iliac fossa because the vascular anastomosis is easier.
When a cadaveric kidney is used, an aortic patch (Carrel patch) is removed with the renal artery.
@#1 17. A 25-year-old man presents with progressive increase in knee pain. Plain films show features of osteoarthrosis with increased soft-tissue swelling and density. An MRI shows diffuse low signal on T2W images to the synovium of the knee on the background of large joint effusion. What is the likely diagnosis?
A. Amyloid arthropathy
B. Haemophilic arthropathy
C. PVNS
D. Primary synovial osteochondromatosis
E. Rapidly destructive articular disease
- B. Haemophilic arthropathy
Radiographic findings vary greatly with the different stages of haemophilic arthropathy (acute, subacute or chronic haemarthrosis) and reflect the presence of haemarthrosis (joint effusion), synovial inflammation and hyperaemia (osteoporosis and epiphyseal overgrowth), chondral erosions and subchondral resorption (osseous erosions and cysts), cartilaginous denudation (joint space narrowing), intraosseous or subperiosteal haemorrhage (pseudotumours) and osseous proliferation (sclerosis and osteophytosis).
Some abnormalities of osseous shape, such as widening of the intercondylar notch, flattening of the condylar surface or squaring of the patella, are very characteristic of chronic haemarthrosis of the knee.
At MR imaging, hypertrophied synovial membrane resulting from repetitive haemarthrosis has characteristic low signal intensity with all pulse sequences, especially with gradient echo sequences, due to the magnetic susceptibility effect caused by haemosiderin.
As in pigmented villonodular synovitis, the signal intensity of the subarticular defects varies and may indicate the presence of fluid (high signal intensity on T2-weighted images), soft tissue (intermediate signal intensity) or synovial tissue with haemosiderin (low signal intensity).
Rapidly destructive articular disease is an unusual form of osteoarthritis that typically involves the hip. The disease is almost always unilateral, but bilateral lesions and involvement of shoulder have also been reported. Serial radiographs show progressive loss of joint space and loss of subchondral bone in the femoral head and acetabulum, resulting in marked flattening and deformity of the femoral head (‘hatchet’ deformity). Superolateral subluxation of the femoral head or intrusion deformity within the ilium can be observed. Most cases demonstrate subchondral defects and mild sclerosis. However, osteophytes are small or absent.
- A 10-year old girl is diagnosed with pilocytic astrocytoma. Which of the following are the most likely findings on MRI?
A. Hyperintense to brain on T1WI and hypointense on T2WI
B. Isointense to brain on T1WI and hypointense on T2WI
C. Isointense to brain on T1WI and isointense on T2WI
D. Hypointense to brain on T1WI and hyperintense on T2WI
E. Hyperintense to brain on T1WI and hyperintense on T2WI
- D. Hypointense to brain on T1WI and hyperintense on T2WI
Pilocytic astrocytoma typically presents in first two decades, with peak age from birth to 9 years of age. It is the most common paediatric glioma, with the majority located in the cerebellum. Pilocytic astrocytomas are predominantly cystic with an intensely enhancing mural nodule; half show enhancement of the cyst wall. The magnetic resonance signal pattern is as for cysts: hypointense on T1-weighted images and hyperintense on T2-weighted images.
Post contrast T1-weighted images shows enhancement of the mural nodule.
- A 53-year-old woman with chronic renal failure and polycystic renal disease had renal transplantation surgery 5 weeks ago. Initial recovery’ was uneventful and she is regularly being followed up by the transplant and the renal team. A follow-up graft ultrasound done at 5 weeks post-surgery reveals a large simple fluid collection in relation to the graft. What is the most likely explanation?
A. Abscess
B. Resolving haematoma
C. Lymphocele
D. Urinoma
E. Seroma
- C. Lymphocele
Urine leaks and urinomas are relatively rare complications and are usually found in the first 2 weeks post-operative between the transplanted kidney and the bladder. They appear as a well-defined, anechoic fluid collection with no septations that increases in size rapidly. Antegrade pyelography is necessary to provide detailed information about the site of origin of the urinoma and in planning appropriate intervention.
Haematomas are common in the immediate post-operative period, but they may also develop spontaneously or as a consequence of trauma or biopsy. At US, haematomas demonstrate a complex appearance. Acute haematomas are echogenic and become less echogenic with time. Older haematomas even appear anechoic, more closely resembling fluid, and septations may develop.
Lymphoceles are the most common peritransplant fluid collections that may develop at any time, from weeks to years after transplantation. However, they usually occur within 1-2 months after transplantation. At US, lymphoceles are anechoic and may have septations. Similar to other peritransplant fluid collections, they can become infected and can develop a more complex appearance.
Abscesses have a complex, cystic, non-specific appearance at US. Peritransplant abscesses are an uncommon complication and usually develop within the first few weeks after transplantation.
@#e 20. All of the following are causes of lower zone fibrosis, except
A. Amiodarone
B. Idiopathic pulmonary fibrosis
C. Asbestosis
D. Ankylosing spondylitis
E. Neurofibromatosis I
- D. Ankylosing spondylitis
Causes of lower zone fibrosis include asbestosis, aspiration, cryptogenic alveolitis (IPF), neurofibromatosis I and tuberous sclerosis; connective tissue diseases like RA, scleroderma and SLE; and drug toxicity to substances like amiodarone and nitrofurantoin.
@# 21. All of the following are true for neurocysticercosis, except
A. There arc four recognised stages on CT/MR.
B. The granular nodular stage is not associated with oedema.
C. The vesicular stage does not show any oedema.
D. The vesicular stage shows a nodule with a ‘hole with dot’ appearance.
E. Colloidal stage shows an avid ring-enhancing capsule.
- B. The granular nodular stage is not associated with oedema.
Neurocysticercosis has been classified into active and non active forms on the basis of clinical presentation, results of CSF analysis and imaging findings.
The active forms include arachnoiditis with or without ventricular obstruction and vasculitis with or without infarction.
On the basis of radiologic findings, neurocysticercosis is divided into five stages: non-cystic, vesicular, colloidal vesicular, granular nodular and calcified nodular. Of these, all the stages apart from the first (non cystic stage) arc visible on CT/MRI.
Vesicular stage: Cyst signal intensity similar to that of CSF on T1-weighted and T2-weighted images; cyst wall is well defined and thin, with little or no enhancement on gadolinium enhanced images; scolex (hole with dot appearance); iso- or hypointense relative to white matter on T1-weighted images; iso- to hyperintense relative to white matter on T2-weighted images; best seen on PD-weighted images.
Colloidal vesicular stage: Cyst contents are hyperintense on T1-weighted and T2-weighted images (proteinaceous fluid), cyst wall is thick and hypointense, pericystic oedema (best seen on FLAIR), pericystic enhancement on gadolinium-enhanced images.
Granular nodular stage: Similar to the colloidal vesicular stage but with more oedema, thicker ring enhancement.
Calcified nodular stage: Hypointense nodules, no oedema, no enhancement.
- A 43-year-old woman currently on treatment for known Crohn’s disease has recently been unwell again with a mildly raised CRP. MRI could not be performed because she wras claustrophobic, so a CT was done instead. Which one of the following statements concerning CT enterography for evaluation of small bowel Crohn’s disease is not true?
A. Patients should ideally ingest 1 L of positive oral contrast medium before the start of the examination.
B. Small bowel distension is a key factor in the examination.
C. Patients should ideally ingest 1 L of negative oral contrast medium before the start of the examination.
D. In CT enterography, CT scanning should start 65 seconds after the start of IV administration of contrast infusion.
E. Patients should fast for 4 hours before the exam.
- A. Patients should ideally ingest 1 L of positive oral contrast medium before the start of the
examination.
Patients undergoing CT enterography are asked to withhold all oral intake, starting 4 hours before the examination. To improve visualisation of the mucosa and achieve better bowel distension, a negative oral contrast agent is administered. A typical regimen with regard to the timing of administration of oral contrast agents involves the ingestion of a total of 1.35 L over 1 hour 450 mL at 60 minutes, 450 mL at 40 minutes, 225 mL at 20 minutes and 225 mL at 10 minutes before scanning. After the oral contrast agent is ingested, a bolus of intravenous contrast material followed by 50 mL of saline solution is administered with a power injector at a rate of 4 mL/sec.
Helical scanning is performed from the diaphragm to the symphysis pubis, beginning 65 seconds after the administration of intravenous contrast material; it includes a single (venous) phase for the evaluation of known or suspected Crohn’s disease or dual (arterial and venous) phases for the evaluation of mesenteric vessels, GI tract bleeding and suspected tumours. Scanning parameters include a section thickness of 0.625 mm and interval of 0.625 mm.
- A 5-year old boy with a large head has widened sutures and Wormian bones on a skull radiograph. Review of other examinations performed earlier shows bilateral hypoplastic clavicles and delayed ossification of symphysis pubis. A chest radiograph shows supernumerary ribs. What is your diagnosis?
A. Hypothyroidism
B. Primary hyperparathyroidism
C. Cleidocranial dysostosis
D. Ehlers-Danlos syndrome
F. Downs syndrome
- C. Cleidocranial dysostosis
Cleidocranial dysplasia (CCD) is characterised by aplasia or hypoplasia of the clavicles, characteristic craniofacial malformations, and the presence of numerous supernumerary and unerupted teeth. Cranial abnormalities include wide open sutures, patent fontanelles and the presence of Wormian bones. Delayed closure of cranial sutures and fontanelles leads to frontal, parietal and occipital bossing. Additionally, there may be poor or absent pneumatization of paranasal, frontal and mastoid, and sphenoid sinuses.
Pelvic features include delayed ossification with wide pubic symphysis, hypoplastic iliac wings, widened sacroiliac joints and a large femoral neck resulting in coxa vara.
The differential diagnosis of CCD includes Crane-Heise syndrome (CCD with cleft lip and agenesis of cervical vertebra), mandibuloacral dysplasia (CCD plus hypoplastic mandible), pyknodysostosis (CCD and osteopetrosis), Yunis-Varon syndrome (CCD with hypoplastic thumb and big toe), CDAGS syndrome (craniosynostosis, anal anomalies and genital hyplasia).
- A child presents following a witnessed first seizure. An MRI scan is arranged. This shows a well-demarcated, T1 hypointense, T2 hyperintense supratentorial mass with a bright rim on FLAIR. There was no enhancement post-contrast. Which of the following is the most likely diagnosis?
A. Ependymoma
B. Dysembryoplastic neuroepithelial tumour
C. Pilocytic astrocytoma
D. Oligodendroglioma
F. Ganglioglioma
- B. Dysembryoplastic neuroepithelial tumour
History of seizure that may be medically refractory makes dysembryoplastic neuroepithelial tumour (DNET) more likely.
DNET is a benign, supratentorial and predominantly cortical intra-axial lesion, characterised by a multinodular architecture. Although DNETs are usually located in the temporal lobe, any lobe within the brain lobes may be involved. They have a cortical base and an apex pointing towards the lateral ventricle. They are homogeneously hyperintense on T2-weighted images and hypointense on T1-weighted images. Some delicate septa like structures are visible within the lesions. Despite their size, neither mass effect nor surrounding parenchymal oedema is present. On FLAIR images, the lesions show a hyperintense ring. Susceptibility-weighted images do not depict any hypointense signal in the lesion, which indicates the absence of calcium or blood products. Very high ADC values are measured inside the mass. No contrast enhancement is noted and there is scalloping of overlying bone.
The differential diagnosis includes other brain tumours, such as ganglioglioma (cyst with a strongly enhancing mural nodule, frequent calcification), angiocentric glioma (hyperintense on Tl and star-like extension to ventricle), low grade astrocytoma (similar to DNET but no scalloping of bone or rim of FLAIR) and pleomorphic xanthoastrocytoma (cyst with mural nodule, enhancement and dural tail).
@#1 25. A 2-year-old girl with headache shows a large cyst in the posterior fossa with communicating hydrocephalus; bone windows reveal scalloping of the petrous pyramids. What is the likely diagnosis?
A. Dandy-Walker malformation
B. Dandy-Walker variant
C. Astrocytoma
D. Haemangioblastoma
E. Chiari malformation
- A. Dandy-Walker malformation
The characteristic triad of the Dandy Walker malformation includes (1) complete or partial agenesis of the vermis, (2) cystic dilatation of the fourth ventricle and (3) an enlarged posterior fossa with upward displacement of the lateral sinuses, tentorium and torcula. The triad is usually associated with hydrocephalus (most common presentation 80%), but this condition should be considered a common complication and not as pan of the malformation itself. Depending on the degree of hydrocephalus, the age at diagnosis varies from the neonatal period to later childhood.
The skull is enlarged, with characteristic thinning and bulging of the occiput. Pressure from the massively dilated fourth ventricle, along with cerebrospinal fluid pulsations, causes erosive scalloping of the occiput and petrous temporal bones.
The cerebellar hemispheres are typically hypoplastic, and in extreme cases only a small nubbin of compressed cerebellar tissue is identified contiguous laterally with the wall of the posterior fossa cyst. Anomalies of the posterior inferior cerebellar arteries, especially absence of the inferior vermian branches and absence of the inferior vermian vein, help in the angiographic differentiation of a Dandy-Walker cyst from an arachnoid cyst, in which the vessels are displaced but present.
The Dandy-Walker variant is used to describe a cystic posterior fossa malformation with varying degrees of agenesis of the vermis associated with expansion (often considerable) of the fourth ventricle, which communicates freely with the perimedullary subarachnoid space.
- HRCT shows numerous, randomly scattered thin walled cysts surrounded by normal lung parenchyma. There is interlobular septal thickening and a left pleural effusion. What is the likeliest diagnosis?
A. Neurofibromatosis
B. Langerhans cell histiocytosis
C. Lymphangiomyomatosis
D. Alfa-1 antitrypsin deficiency
E. Lymphocytic interstitial pneumonia
- C. Lymphangioleiomyomatosis
Lymphangioleiomyomatosis (LAM) is a rare disorder occurring almost exclusively in women of childbearing age. LAM associated with tuberous sclerosis is 5-10 times more common than sporadic LAM. Lymphatic obstruction may result in chylous pleural effusion, chylous ascites or both. Spontaneous or recurrent pneumothorax may be the presenting finding in up to 50% of patients.
Characteristic HRCT features of LAM are diffuse thin-walled cysts surrounded by normal lung without regional sparing. Cysts are usually 2-5 mm but can be as large as 25-30 mm. Cysts are typically round or ovoid, but they may become polygonal with severe parenchymal involvement. Small centrilobular nodules and focal ground-glass opacities have been reported. Lymphatic obstruction may cause septal thickening.
- A 23-year-old woman with recent diagnosis of Crohn’s disease is referred for cross-sectional imaging to assess disease status by the gastroenterology team. She has been booked
for MR enterography and will be followed up with MRI. Which of the following statement is false?
A. MR enterography has less sensitivity and specificity compared to MR enteroclysis for established disease.
B. MR enteroclysis is better than MR enterography for demonstrating mucosal abnormalities.
C. MR imaging provides superior soft-tissue contrast and excellent depiction of fluid and oedema.
D. MR enterography is more acceptable to the patient than MR enteroclysis.
E. Jejunal distension is better with MR enteroclysis.
- A. MR enterography has less sensitivity and specificity compared to MR enteroclysis for established disease.
The benefits of using enteric contrast material to achieve bowel distension for cross-sectional imaging are not disputed, although the optimal type of contrast material and method of administration remain somewhat controversial.
Current data suggest that although bowel distension achieved with the enteric intubation technique generally is superior to that achieved with enterography, the improved distension does not necessarily translate into a clinically significant improvement in diagnostic effectiveness.
A recent study confirmed the benefit of enteric intubation for bowel distension but reported equivalent diagnostic performances with the enteric and oral techniques in identifying stenoses and fistulas. However, MR enteroclysis was superior to MR enterography in demonstrating mucosal abnormalities. The importance of detecting mucosal disease in patients without bowel obstruction has diminished in the era of capsule endoscopy. Patient acceptance, which favours MR enterography over MR enteroclysis, also must be considered, because many patients need multiple examinations.
@#1 28. An adolescent with growth disturbance presents with a visual difficulty. A non-calcified, thin-walled cyst with no enhancement is seen in the intrasellar region on MRI.
Which of the following is the most likely diagnosis?
A. Craniopharyngioma
B. Macroadenoma
C. Epidermoid
D. Rathke cleft cyst
E. Metastasis
- D. Rathke cleft cyst
Rathke cleft cysts are benign cystic sellar lesions that are generally asymptomatic, but they may be associated with hypopituitarism, visual disturbance and headache. At MR imaging, Rathke cleft cysts have a variable Tl signal, depending on the protein concentration. Cysts with high protein content demonstrate high Tl signal and usually low intracystic water content that leads to T2 signal decrease. Thus, typical Rathke cleft cysts appear as non-enhancing well demarcated intrasellar rounded lesions located exactly at the midline between the anterior and posterior pituitary lobes. The cysts have a homogeneously hyperintense Tl signal and, often, a hypointense T2 signal. Axial images are crucial for identifying the specific location and characteristic kidney shape of a Rathke cleft cyst.
The presence of fluid-fluid level or haemorrhagic debris in an intrasellar lesion suggests a pituitary adenoma, because a Rathke deft cyst almost never bleeds.
Craniopharyngioma typically appears as intrasellar or suprasellar heterogeneously enhancing lesions with a tripartite structure of solid, calcified and cystic components. They are difficult to distinguish from pituitary adenoma, although the fluid fluid level is more likely to suggest a pituitary adenoma.
- A 56-year-old woman shows an 8-cm solid enhancing mass in the left kidney with a central area of low attenuation on contrast-enhanced CT scan. US study performed earlier showed a large heterogeneous solid mass in the left kidney with a central stellate hypoechoic area. The most likely diagnosis based on the imaging finding would be
A. Renal cell carcinoma
B. Clear cell carcinoma
C. Rhabdomyoma
D. Adenoma
E. Oncocytoma
- E. Oncocytoma
Oncocytomas are tubular adenomas with a specific histological appearance. They were previously considered benign but have now been recognised to metastasise. They vary from 1 to 20 cm in diameter and tend to be large. They are usually solitary and unilateral. US shows a solid mass with internal echoes, which occasionally have a stellate hypoechoic centre. CECT demonstrates a well-defined solid mass, with a low-attenuation central scar, when large. Large lesions can extend into and engulf perinephric fat. RCC and oncocytoma look similar on MRI.
@#1 30. A 25-year-old man has injured his knee. Sagittal T2W MRI sequences show a double posterior cruciate ligament (PCL) sign. Which of the following is the most likely injury?
A. Ruptured PCL
B. Bucket-handle tear of meniscus
C. Osteochondral fragmentation
D. Radial tear of meniscus
F. . Anterior cruciate ligament (ACL)
- B. Bucket-handle tear of meniscus
Bucket-handle tears of the meniscus involve displacement of the free edge of the meniscus into the intercondylar notch. The free edge can be seen adjacent to the PCL on sagittal images giving a double PCL sign. On coronal imaging, the meniscal fragment is displaced medially. A radial mcniscal tear manifests as a linear collection of high signal in the meniscus that extends to the superior or inferior articular surfaces. Rupture of the ACL or PCL results in the ligament losing die normal position and morphology but not a double PCL sign. When assessing the PCL, be aware that the ligaments of Humphrey and Wrisberg can give the impression of a tear to the inexperienced eye. These ligaments are extensions of the meniscofemoral ligament; the ligament of Humphrey passes anterior to the PCL and the ligament of Wrisberg posteriorly.
- A 40-year-old man presents with shortness of breath. Chest X-ray shows a diffuse bilateral reticulonodular pattern within the middle and upper zones. There are multiple small cysts in keeping with honeycomb lung. The lung volumes are preserved. What is the most likely diagnosis?
A. Langerhans cell histiocytosis
B. Lymphangiomyomatosis
C. Centrilobular emphysema
D. Idiopathic pulmonary fibrosis
E. Allergic bronchopulmonary aspergillosis
- A. Langerhans cell histiocytosis
Pulmonary LCH is a smoking-related lung disease. Peribronchiolar nodules are found; they may subsequently cavitate and form thick- and thin-walled cysts. Frequently, both nodules and cysts are seen. Cysts may be round but are often irregular, clover-leaf or bizarre shapes. Irregular cysts, cysts with nodules and upper zone predominance with sparing of the costophrenic angles are features that distinguish LCH from lymphangioleiomyomatosis.
Centrilobular emphysema represents the permanent destruction of bronchiolar walls with resultant enlargement of the airspaces distal to the terminal bronchiole. The distinguishing features of centrilobular emphysema include the lack of a perceptible cyst wall and the central location of the vascular structures (central dot sign).
@#1 32. A 67-year-old woman with systemic amyloidosis diagnosed on rectal biopsy presents to her GP with progressive central abdominal pain, bloating, and abdominal distension. All of the following are abnormalities due to amyloid infiltration in the gastrointestinal tract, except
A. Jejunization of the ileum
B. Macroglossia
C. Gastroesophageal reflux
D. Diffuse nodular wall thickening in small bowel
E. Colonic dilatation due to adynamic ileus
- A. ‘Jejunisation’ of the ileum
In both primary and secondary amyloidosis, the most commonly involved organ system is the gastrointestinal system, with the colon being the most frequently involved organ. Oesophageal and gastric involvement usually manifests as dysmotility, wall thickening and gastroesophageal reflux disease. This results from amyloid infiltration of the muscularis and/or destruction of the Auerbach plexus. When the small intestine is involved, the most common finding is diffuse or nodular wall thickening. Abdominal pain, malabsorption and haemorrhage are rare complications. Colonic biopsy specimens are positive in 80% of patients with systemic amyloidosis.
Contrary to the high pathologic specificity, radiologic findings are rare and non-specific.
The most common finding is colonic dilatation owing to adynamic ileus and more rarely bowel wall thickening. Even more rarely, intramural bowel haemorrhage or perforation can occur.
Splenomegaly is the only finding associated with splenic involvement This causes increased fragility, and spontaneous rupture can ensue with life threatening consequences. The liver is also commonly involved, but radiologic signs are also non-specific. Diffuse infiltration is the rule, which causes decreased attenuation at CT and hepatomegaly.
Macroglossia can also result from amyloid infiltration of the intrinsic muscles. Jejunisation of the ileum can be seen with coeliac disease.
@#1 33. A 44-year-old man with a painful right index finger and positive Love’s test undergoes a plain film study, which shows extrinsic erosion involving the terminal phalanx with a preserved sclerotic rim. There is no definite history of previous injury to the index finger. MRI is performed for further characterisation, which shows a homogenously high-signal lesion on T2W images in a subungual location. What is your diagnosis?
A. Epidermoid inclusion cyst
B. Glomus tumour
C. Implantation dermoid cyst
D. Soft-tissue component of osteosarcoma
E. Giant cell tumour of the tendon sheath
- B. Glomus tumour
A glomus tumour is a hamartoma arising from the glomus body within the dermis of the finger. The subungual position is characteristic of the lesion, which results in extrinsic erosion of the adjacent terminal phalanx. The tumour can also occur entirely within bone, although this is less common. It exhibits intense high T2 signal with avid contrast enhancement as it is a highly vascular lesion.
Epidermoid inclusion cysts, otherwise known as implantation dermoid cysts, are associated with a history of penetrating trauma.
A giant cell tumour of the tendon sheath lies in close relation to the tendon and does not exhibit such intense T2 signal.
The description is not compatible with a soft-tissue osteosarcoma.
@#1 34. A 66-year-old man with a palpable mass in the left loin and painless haematuria undergoes a staging CT of the abdomen for renal cell carcinoma. The staging CT shows a 6 cm heterogeneous, solid left renal mass with direct extension into the perinephric fat. Tumour mass is seen in the left renal vein extending into the IVC, but this is confined to below the level of the diaphragm. What is the T stage?
A. T1
B. T2
C. T3a
D. T3b
E. T3c
- D. T3b
T-stage
T1a: Limited to kidney, <4 cm
T1b: Limited to kidney, >4 cm but <7 cm
T2a: Limited to kidney, >7 cm but not more than 10 cm
T2b: Limited to kidney, >10 cm
T3a: Spread to perinephric fat
T3b: Spread to renal vein or IVC below diaphragm
T3c: Spread to supra diaphragmatic I VC or invades the wall of the IVC
T4: Involves ipsilateral adrenal gland or invades beyond Gerota’s fascia
N-stage
N0: No nodal involvement N1: Metastasis to one regional lymph node(s)
M-stage
M0: No distant metastases M1: Distant metastases
- A 25-year old man with headache shows a heterogeneous mass on T2W MRI, in the fourth ventricle. No contrast enhancement is evident, but closer inspection reveals subarachnoid fat droplets in the ambient cisterns and a fat fluid level in the ventricles. What is the diagnosis?
A. Epidermoid cyst
B. Uncomplicated dermoid cyst
C. Ruptured dermoid cyst
D. Arachnoid cyst
E. Infected arachnoid cyst
- C. Ruptured dermoid cyst
Dermoid cysts are congenital ectodermal inclusion cysts. They tend to occur in the midline sellar, parasellar, or frontonasal regions or in the posterior fossa, where they occur either as vermian lesions or within the fourth ventricle.
Imaging findings vary, depending on whether the cyst has ruptured. Unruptured cysts have the same imaging characteristics as fat because they contain liquid cholesterol. All are hyperintense on T1-weighted images and do not enhance. The masses have heterogeneous signal intensity on T2-weighted images and vary from hypo- to hyperintense. The best diagnostic clue of a ruptured dermoid cyst is fatlike droplets in the subarachnoid cisterns, sulci and ventricles. Extensive pial enhancement can be seen from chemical meningitis caused by ruptured cysts.
Dermoid cysts may be confused with an epidermoid cyst, craniopharyngioma, teratoma or lipoma. Epidermoid cysts typically resemble CSF (not fat), lack dermal appendages, and are usually located off-midline. Like dermoid cysts, craniopharyngiomas are suprasellar, with a midline location, and demonstrate nodular calcification. However, most craniopharyngiomas are strikingly hyperintense on T2-weighted images and enhance strongly. Teratomas may also have a similar location but usually occur in the pineal region. Lipomas demonstrate homogeneous fat attenuation and/or signal intensity and show a chemical shift artefact, which typically does not occur with dermoid cysts.
- An 11 day- old child presents with duct-dependant cyanosis and congestive cardiac failure. Chest X-ray shows an enlarged heart with a figure of eight pattern and prominent veins. What is the likely diagnosis?
A. Transposition of the great vessels (TGA)
B. Truncus arteriosus
C. Tetralogy of Fallot
D. Vein of Galen aneurysm
E. Total anomalous pulmonary venous return (TAPVR)
- E. Total anomalous pulmonary venous return (TAPVR)
TAPVR occurs when the pulmonary veins fail to drain into the left atrium and instead form an aberrant connection with some other cardiovascular structure.
On chest radiographs, this cardiovascular anomaly resembles a snowman (figure of eight appearance). In infants affected by TAPVR, cyanosis and congestive heart failure typically develop in the early neonatal period.
TA, TGA typically does not present with heart failure. Vein of Galen aneurysm presents with features of heart failure on a chest X-ray but without any specific pattern.
@#e 37. A middle-aged man presents with easy fatigability. CT shows an anterior mediastinal mass with areas of calcifications, invading the mediastinal structures. There are multiple small pleural masses. What is the most likely diagnosis?
A. Thymoma
B. Thymic lipoma
C. Lymphoma
D. Teratoma
E. Asbestosis
- A. Thymoma
Thymomas are classified as encapsulated, infiltrative and metastasising, with pulmonary and pleural deposits and thymic carcinoma. Half the thymomas are asymptomatic and 30% are associated with myasthenia gravis.
At CT a benign thymoma appears round, oval or lobulated. Focal calcification is seen in 25%, which may be dense, irregular or coarse. Benign thymomas show mild homogenous enhancement; cystic changes are also described. Invasive thymoma are heterogeneous in appearance; pericardial and pleural nodules suggest malignancy. Egg-shell calcification is described in invasive thymoma. Absent fat planes between thymoma and mediastinum does not necessarily reflect invasion.
- A 27-year-old man is complaining of central umbilical pain, which has gradually settled in the right iliac fossa with local guarding and rebound tenderness suggesting local peritonitis. Clinical features suggest acute appendicitis; however, an apparent mass is felt in the right iliac fossa, which prompts a CT scan.
Which one of the following CT findings has the highest specificity and sensitivity for perforated appendicitis?
A. Free intra-abdominal fluid
B. Enlarged periappendiceal lymph nodes
C. Periappendiceal abscess
D. Periappendiceal fluid
E. Focal appendiceal wall enhancement defect
- E. Focal appendiceal wall enhancement defect
Defect in enhancing appendiceal wall has the highest specificity (100%) and sensitivity (64.3%) for indicating perforated appendicitis.
- A 22-year-old man involved in an RTA is admitted to ITU with multi-organ injury in an obtunded state. Initial CT is thought to be normal and an MRI is organised. Limited sequence MR scan reveals several round foci of low Tl, high T2 signal change bilaterally at the grey-white interface with further areas in the splenium of the corpus callosum. What is the diagnosis?
A. Multiple sclerosis
B. Vasculitis
C. Diffuse axonal injury
D. Infection
E. Neurosarcoid
- C. Diffuse axonal injury
Diffuse axonal injury (DAI) is a type of brain damage that is secondary’ to rotational acceleration/deceleration. MR can identify DAI lesions, whereas CT scan often fails to do so. T2-weighted images show high signal with blooming artefact. SWI (or GRE) sequences, exquisitely sensitive to blood products, may demonstrate small regions of susceptibility artefact at the grey-white matter junction, in the corpus callosum or the brain stem.
DAI is classified into three stages: the involvement of the grey-white matter junction indicates Stage I; corpus callosum involvement, particularly the splenium, indicates Stage II; and brainstem involvement indicates Stage III. Clinical studies demonstrate that the prognosis becomes poorer as deeper structures are involved.
- A 42 year old woman with hereditary non-polyposis colon cancer syndrome (HNPCC) shows a suspicious filling defect in the left renal pelvis on IVU, which is subsequently confirmed on CT urography. She is currently being investigated for haematuria and left loin pain. What is the most likely diagnosis, given her genetic background?
A. Renal lymphoma
B. TCC of the renal pelvis
C. Squamous cell cancer of the renal pelvis
D. Renal metastasis
E. Endometriosis
- B. TCC of the renal pelvis
Hereditary non-polyposis colon cancer syndrome (HNPCC) is an autosomal dominant condition that is associated with a high incidence of tumours of the renal pelvis, colorectal cancer, and tumours of the ovaries and small bowel. Squamous cell carcinoma of the renal pelvis is rare and is a highly aggressive tumour with a poor prognosis. Chronic infection and calculi play an important aetiological role in this malignancy, and stones are present in 57% of patients.
Renal lymphomas typically demonstrate sheet-like diffuse infiltration of the perirenal tissues or multiple low-attenuation focal lesions. Renal metastases are usually small (<3 cm), multiple and confined to the cortex. They are associated with metastases elsewhere, are of low attenuation, do not calcify, and do not invade the renal vein; they are also more infiltrative than exophytic compared to renal cell carcinoma.
- A 15-year-old boy with haemophilia presents to his GP with progressive worsening of right knee pain. Plain films exclude the presence of a fracture. AD of the following are features of haemophilic arthropathy affecting the knee, except
A. Epiphyseal enlargement
B. Widened intercondylar notch
C. Squared patella
D. Flattening of femoral condyles
E. Erlenmeyer flask deformity
- E. Erlenmeyer flask deformity
Erlenmeyer flask deformity is associated with thalassaemia.
Non specific findings of haemophilic arthropathy include joint effusion and periarticular osteopaenia from hyperaemia. Classical features include epiphyseal enlargement with associated gracile diaphysis (differentials are juvenile rheumatoid arthritis). Secondary degenerative disease with symmetrical loss of joint cartilage involving all compartments equally with periarticular erosions, subchondral cysts, osteophytes and sclerosis is seen in end-stage arthropathy.
Specific findings at the knee include widened intercondylar notch, squared margins of the patella, expanded femoral condyles and flattened surface of femoral condyles.
Specific findings at the elbow include enlargement of the radial head and widening of the trochlear notch.
@#1 42. A 7-year-old boy presents with acute scrotum. Which one of the following features on ultrasound is more suggestive of a diagnosis other than testicular torsion?
A. Abnormal testicular texture
B. Testicular swelling
C. Coded spermatic cord
D. Scrotal wall oedema
E. Decreased or absent blood flow
- D. Scrotal wall oedema
Differential diagnosis of acute scrotum includes testicular torsion (the most important differential) along with torsion of the testicular appendix, epididymitis and epididymo-orchitis. US (including the use of Doppler imaging) plays a vital role in distinguishing between these diagnoses. All of the above features can be seen in testicular torsion, along with such findings as epididymal enlargement and hydrocoele. However, scrotal wall oedema is the only one of these findings that is more commonly seen with alternative causes of acute scrotum than it is with acute testicular torsion. Decreased or absent blood flow is considered the most important finding, although torsion is not excluded if there is normal or increased blood flow, which may occur after spontaneous detorsion.
- AD of the following are true of herpes simplex encephalitis, except
A. It mostly affects the limbic system.
B. CT may be negative in the first few days.
C. There is a tendency for haemorrhage.
D. Increased signal is seen on T2W images in the temporal lobe.
E. DWI shows low signal in the affected area.
- E. DWI shows low signal in the affected area.
In the immunocompetent adult patient, the pattern is quite typical and manifests as a bilateral asymmetrical involvement of the limbic system, medial temporal lobes, insular cortices and inferolateral frontal lobes. The basal ganglia are typically spared. Extralimbic involvement is more prevalent in children than in adults, seen most commonly in the parietal lobe, with sparing of the basal ganglia. Eventually, it results in marked cystic encephalomalacia and volume loss in affected areas.
In immunocompromised patients, involvement can be more diffuse and is more likely to involve the brainstem. Early diagnosis is difficult and a ‘normal’ CT is often seen. Affected areas appear low on T1-weighted MRI due to oedema. High T1 signal suggests areas of haemorrhage. Post-contrast enhancement is usually late and can be gyral, leptomeningeal, ring or diffuse enhancement. Affected white matter and cortex appears high signal on T2-weighted and FLAIR images. Areas of haemorrhage show low T2 signal and blooming artefact. DWI is more sensitive than T2-weighted images. Cytotoxic oedema is seen as high signal on DWI with corresponding low signal on ADC map. Vasogenic oedema is bright on both (T2 shine-through).
- CXR demonstrates a mediastinal mass. The heart borders are not obscured and the hilar vessels are visible. Which of the following is in keeping with the CXR findings?
A. Lymphoma
B. Teratoma
C. Retrosternal goiter
D. Nerve sheath tumour
E. Left ventricular aneurysm
- D. Nerve sheath tumour
Anatomical and radiological division of the mediastinum into anterior, middle and posterior varies. Anatomically, structures in the pericardial space including great vessels constitute the middle mediastinum; structures anterior to the pericardial sac constitute the anterior mediastinum, and structures behind the sac constitute the posterior mediastinum. The Felson method of radiological division is based on lateral chest radiography. A line extending from the diaphragm to the thoracic inlet along the back of the heart and anterior to the trachea separates the anterior and middle mediastinum, whereas a line that connects points 1 cm behind the anterior margins of the vertebral bodies separates the middle and posterior mediastinal compartments.
The hilum overlay sign is present when the normal hilar structures project through a mass, meaning that the mass is either anterior or posterior to the hilum. Loss of anterior junction line and cardiac contours would suggest anterior location; preservation of these lines and the loss or widening of the posterior junction lines, paraspinal lines, would suggest posterior location.
Lymphoma, teratoma and goitre are anterior mediastinal masses. Nerve sheath tumours arc the only true posterior mediastinal structures amongst the examples.
@#1 45. A 27-year-old woman is complaining of lower abdominal pain localised to the left iliac fossa. A CT scan raises a suspicion of epiploic appendagitis. All of the following statements about epiploic appendagitis are true, except
A. Treatment is usually medical.
B. It can mimic acute appendicitis or diverticulitis.
C. It is usually associated with change in bowel habits.
D. Most patients have normal inflammatory markers.
E. The most common site of appendagitis is adjacent to the sigmoid colon.
- C. It is usually associated with change in bowel habits
The condition most commonly manifests in the fourth to fifth decades of life, predominantly in men. With diagnosis based on clinical manifestations alone, acute epiploic appendagitis is misdiagnosed in the majority of patients. Clinically, acute epiploic appendagitis manifests with acute onset of pain, most often in the left lower quadrant, and this symptom often leads to its being mistaken for acute diverticulitis. Unlike acute epiploic appendagitis, acute diverticulitis is more likely to manifest with evenly distributed lower abdominal pain and to be associated with nausea, fever and leucocytosis. Although most patients with acute epiploic appendagitis do not report any change in their bowel habits, a minority experience constipation or diarrhoea.
Most patients with acute epiploic appendagitis have a normal white blood cell count and body temperature. CT images from less than 8% of patients evaluated for exclusion of sigmoid diverticulitis or appendicitis show features of primary acute epiploic appendagitis. When acute epiploic appendagitis involves the cecum or ascending colon, it may be mistaken clinically for acute appendicitis.
The most common sites of acute epiploic appendagitis, in order of decreasing frequency, are areas adjacent to the sigmoid colon, the descending colon and the right hemicolon.
@#1 46. A 35 year old man undergoing a plain abdominal X-ray in the A&E department reveals multiple punctuate areas of calcification over both renal areas. Review of the notes reveals a history of upper GI endoscopy and previous psychiatric consultations. Which of the following are you going to suggest in your report?
A. Urology referral and check of serum TSH levels
B. Urology referral and check of serum parathyroid hormone levels
C. Urology referral and check of serum alkaline phosphatase
D. Urology referral and check of serum LDH
E. Urology referral and check of serum calcitonin levels
- B. Urology referral and check of serum parathyroid hormone levels.
The most common clinical manifestations of hyperparathyroidism include renal stones and nephrocalcinosis, high blood pressure, acute arthropathy (CPPD), osteoporosis, peptic ulcer, acute pancreatitis, proximal muscle weakness, depression and confusional state (often described in medical text books as ‘stones, groans and moans’). It is diagnosed by raised serum parathormone levels.
Serum TSH levels are related to hyper- and hypothyroidism.
Calcitonin is typically raised in medullary carcinoma of the thyroid.
Serum alkaline phosphatase is a nonspecific enzyme marker, which is raised, in several inflammatory, metabolic and malignant conditions.
LDH is also a non-specific enzyme marker, raised in heart disease and myositis.
- A previously well 29 year-old presents with inversion injury. An X-ray demonstrates no fracture. However, there is a well-circumscribed lesion in the tibia with a ground-glass matrix and a narrow zone of transition. There is no periosteal reaction or associated soft-tissue mass. Which of the following is the most likely diagnosis?
A. Polyostotic fibrous dysplasia
B. Osteosarcoma
C. Osteoid osteoma
D. Adamantinoma
E. Monostotic fibrous dysplasia
- E. Monostotic fibrous dysplasia
Fibrous dysplasia is an uncommon, benign disorder characterised by a tumour-like proliferation of fibro-osseous tissue. It may either present as monostotic (affecting one bone) or polyostotic (affecting many bones). Fibrous dysplasia is usually found in the proximal femur.
tibia, humerus, ribs and craniofacial bones in decreasing order of incidence. Polyostotic cases can affect multiple adjacent bones or multiple extremities. Men and women are equally affected by the disorder.
Fibrous dysplasia is usually asymptomatic, although pain and swelling may accompany the lesion. Radiographically, fibrous dysplasia appears as a well-circumscribed lesion in a long bone with a ground-glass or hazy appearance of the matrix. There is a narrow zone of transition and no periosteal reaction or soft-tissue mass. The lesions are normally located in the metaphysis or diaphysis. There is sometimes focal thinning of the overlying cortex, called ‘scalloping from within’. The radiological appearance can also be cystic, pagetoid, or dense and sclerotic. Repeated fractures through lesions in the proximal femur can result in the formation of a so-called shepherd’s crook deformity. The Tc-99m bone scan uptake may be normal or increased. Bone scans are not helpful in diagnosing these lesions but can be useful in identifying asymptomatic lesions. MR! or CT scans can be helpful in delineating the extent of the lesion and identifying possible pathological fractures. Sarcomatous change within the lesion can be identified by MRI or CT.
@#1 48. A 2-year-old boy presents with bowing of the left leg. There is no history’ of trauma and the right leg appears normal. Standing anteroposterior radiography is performed. This shows a varus deformity of the left knee with fragmentation of the posteromedial tibial metaphysis and absence of the medial epiphysis. The right leg appears radiographically normal and bony density is preserved throughout. Which of the following is the most likely cause?
A. Neurofibromatosis
B. Blount disease
C. Congenital bowing
D. Developmental bowing
E. Osteogenesis imperfecta
- B. Blount disease
All of the answers can lead to leg bowing in paediatric groups. However, the description is that of Blount disease, otherwise known as tibia vara. This is a common condition that is unilateral or asymmetrical and is thought to arise as a result of abnormal stress (such as obesity and walking at an early age) on the posteromedial proximal tibial physis. There are three types: infantile (the most common), juvenile and adolescent. Anteroposterior radiography of both legs is necessary.
Neurofibromatosis may cause anterolateral tibial bowing, possibly with fibular hypoplasia, and one or both bones may fracture to give a pseudarthrosis. Developmental or physiological bowing is where there is exaggeration of varus angulation between the ages of 12 and 24 months, which again may be caused by obesity or early walking. There is metaphyseal beaking but no fragmentation, and it is usually symmetrical and bilateral.
Congenital bowing is usually convex posteromedially (unlike neurofibromatosis). Marked dorsiflexion of the foot is evident at birth, as this condition is thought to arise from an abnormal intrauterine position. Radiography shows thickening of the cortex of the concavity of the curvature.
Osteogenesis imperfecta causes bowing of multiple long bones as a result of osteoporotic softening and fractures; hence bone density reduction and bilateral bowing would be more likely.
@#1 58. A 25-year-old woman presents to the A&E department with an acutely painful right hip and difficulty in weight-bearing. A radiograph is obtained in casualty. No fractures are identified but the radiograph reveals a subluxed femoral head on the right with a shallow acetabulum and a centre-edge angle of 18 degrees. What is your diagnosis?
A. Perthes disease
B. Ollier’s disease
C. Developmental dysplasia of the hip
D. Traumatic subluxation
E. Congenital coxa vara with subluxation
- C. Developmental dysplasia of the hip
The patient has developmental dysplasia of the hip, which has resulted in subluxation of the femoral head. The centre edge angle is useful in older toddlers up to adulthood to estimate the degree of acetabular over or under coverage. It is the angle between a vertical line drawn up from the centre of the femoral head and the outer edge of the acetabular roof. In an adult, an angle less than 20 degrees indicates underlying dysplasia.
Perthes disease is a paediatric condition characterised by avascular necrosis of the femoral head.
Ollier’s disease is the condition of multiple enchondromas (enchondromatosis).
Isolated traumatic subluxation requires significant trauma in the absence of an underlying dysplasia.
- MRI brain on a patient with head injury shows a 3 x 3 cm haematoma in the right occipital lobe, which retuns high signals on both T1W and T2W images. What is the phase of the intracerebral haematoma?
A. Hyperacute
B. Acute
C. Early subacute
D. Late subacute
E. Chronic
- D. Late subacute
