Model Answers
Case 1
Case 1 Model Answer:
Findings and interpretation:
- There is a lobulated, ill defined, large anterior mediastinal mass; this shows central areas of low density in some regions. The mass shows moderate, mostly homogeneous post-contrast enhancement, except for a single low density central area which shows little enhancement; this most likely represents a central necrotic area.
- The mass is encasing the mediastinal vessels without invasion; mild compression of the left brachiocephalic vein is noted.
- There are two cavitating lesions in the right lung.
- There are other round, lobulated solid nodules / masses in the lungs.
Pertinent negative findings:
- There are no fat densities / calcifications in the anterior mediastinal mass.
- No filling defects in the pulmonary arteries to suggest pulmonary embolism.
The mediastinal lesion represents conglomerated lymph nodal masses. The lesions in the lungs likely represent spread of the disease.
Principal diagnosis:
Lymphoma
Differential diagnosis:
Thoracic tuberculosis (however, the lymph nodes in tuberculosis typically show more central necrosis and peripheral enhancement)
Management:
Alert referring physician of findings.
Recommend image guided biopsy for tissue diagnosis and further management.
Case 1 Your Answer:
Case 2
Case 2 Model Answer:
Findings and interpretation:
- The pancreas is atrophic with a dilated main duct and side ducts; there are many coarse calcifications in the pancreatic parenchyma at the head and neck, some of which lie along the duct and may be intraductal.
- There is intra and extra-hepatic bile duct dilatation, down to the level of the distal CBD / ampulla.
- There are innumerable small cystic lesions in the liver (showing fluid signal intensity on the T2 images), which cluster around the peripheral bile ducts; there is also a larger cystic lesion at the left lateral segments (representing an abscess).
- There is non-enhancement of the left portal vein, the right posterior sectoral portal vein, and other peripheral branches of the right portal vein indicating thrombosis.
- There is a marked amount of abdominal / peritoneal free fluid.
- The gallbladder wall is congested.
Pertinent negative findings:
- No pancreatic head mass.
The findings represent chronic pancreatitis and obstruction of the biliary tree at the level of the distal CBD / ampulla; since there is no mass detected, this is most likely caused by a chronic inflammatory stricture. There are hepatic cholangitic micro-abscesses which have developed as a result of ascending cholangitis due to biliary obstruction. There is also partial portal vein thrombosis.
Principal diagnosis:
Chronic pancreatitis causing a distal CBD stricture, which has caused ascending cholangitis complicated by hepatic micro-abscesses and portal vein thrombosis.
Differential diagnosis:
None.
Management:
Alert referring physician of findings.
Recommend percutaneous hepatic biliary drainage (inserting an internal/external biliary drain by interventional radiology).
Case 2 Your Answer:
Case 3
Case 3 Model Answer:
Findings and interpretation:
- There is partial soft tissue opacification of the right ethmoid air cells.
- The medial wall of the right orbit is sclerotic, and shows extension of a collection with a thick and enhancing wall into the right orbit, containing fluid and a focus of air; this represents a sub-periosteal abscess.
- There is marked stranding of the intra and extra-conal fat around the abscess in the post septal space.
- There is lateral displacement of the medial rectus muscle by mass effect. This is also causing proptosis of the right globe.
- There is polypoidal mucosal thickening in the right maxillary sinus, extending into the right sphenoid sinus. The right osteomeatal complex is occluded.
Pertinent negative findings:
- There is no evidence of intracranial extension of disease / involvement of the cavernous sinus.
There is an infectious / inflammatory condition originating from the paranasal sinuses (sinusitis) and extending into the post-septal space of the right orbit.
Principal diagnosis:
Paranasal sinusitis complicated by right orbital cellulitis.
Differential diagnosis:
None.
Management:
Urgently alert referring physician of findings. Recommend ophthalmic surgery consultation.
The patient will require IV antibiotics and possibly surgical management to drain the abscess.
Case 3 Your Answer:
Case 4
Case 4 Model Answer:
Findings and interpretation:
- There are bilateral retro-glandular breast implants.
- There is bilateral capsular thickening around both implants, which show post contrast enhancement.
- There are T1 hypointense and T2 hyperintense fluid collections surrounding both prostheses, the right side showing a greater amount. The peri-implant collection on the right side is multi-septated and complex.
- There is increased antero-posterior diameter of the left sided implant, which also shows a high number of radial folds.
Pertinent negative findings:
- There is no implant rupture on either side.
The findings represent inflammation of the peri-implant capsule bilaterally, with bilateral peri-implant seromas.
There is also capsular contracture on the left side.
Principal diagnosis:
Bilateral capsulitis and left sided capsular contracture.
Differential diagnosis:
- Peri-implant hematoma or abscess.
Management:
Aspiration of the peri-implant fluid may be performed.
Refer to breast surgeon for possible capsulectomy.
Case 4 Your Answer:
Case 5
Case 5 Model Answer:
Findings and interpretation:
- The liver shows a markedly irregular contour with fibrotic and calcified septations / bands crisscrossing the liver and causing capsular retraction, resulting in a characteristic ‘turtle back’ appearance.
- There is atrophy of the right lobe and hypertrophy of the left lobe of the liver.
- The caudate lobe is disproportionately enlarged compared to the rest of the liver.
- There is dense linear mural calcification at the walls of the cecum and the sigmoid, descending and ascending colon.
Pertinent negative findings:
- No splenomegaly.
- No involvement of the urinary tract.
The findings represent sequelae of chronic intestinal and hepatic schistosomiasis.
Principal diagnosis:
Chronic intestinal and hepatic infection with schistosomiasis Japonicum.
Differential diagnosis:
None in this case.
Management:
Recommend referral to infectious disease specialist.
Case 5 Your Answer:
Case 6
Case 6 Model Answer:
Findings and interpretation:
- The lower lumbar vertebrae as well as the sacrum have unfused posterior bony elements, indicating a spina bifida defect.
- There is a low lying / tethered cord with the conus medullaris ending at L3 level.
- There is a subcutaneous fatty mass above the level of the inter-gluteal crease; the thecal sac is widened at this level behind the fatty mass and extrudes posteriorly into the lipoma.
- The distorted filum terminale extends to the placode which herniates through the spinal defect and attaches to the lipoma.
The findings represent a congenital malformation of the spine and spinal cord, which can be classified as closed spinal dysraphism.
Diagnosis:
Lipomyelomeningocele.
Differential diagnosis:
Lipomyelocele.
Management:
Recommend discussion at spinal surgery MDT with regards to further management.