Model Answers
Case 1
Case 1 Model Answer:
Findings and interpretation:
- There is marked dilatation of loops of ileum; the distal dilated loops contain mottled particulate matter and gas foci characteristic of fecal material. This is the small bowel faeces sign.
- There is wall thickening of a long segment of distal ileum at the transition point of dilated small bowel, also showing hyper-enhancement of the mucosa.
- This loop of terminal ileum shows alternating luminal stenosis and dilatation.
- There is a round collection of fluid with foci of gas, surrounded by a thick, enhancing wall. This is located immediately deep to the rectus abdominus muscle at the lower abdomen. This represents an abscess.
- There is a small amount of free peritoneal fluid.
Incidental findings:
- Both kidneys are enlarged with innumerable cysts of varying sizes.
- There are a few small, well-defined hypodense lesions throughout the liver. These represent simple cysts.
There is an inflammatory condition involving the terminal ileum, which has caused multi-focal obstructing stenoses in the distal ileum (fibro-stenosing disease). This has resulted in small bowel obstruction, as well as adjacent abscess formation.
The patient incidentally has a congenital condition causing cyst formation in the kidneys and liver.
Principal diagnosis:
Fibro-stenosing Crohn’s disease complicated by small bowel obstruction and intra-peritoneal abscess formation in a patient with a background of autosomal dominant polycystic kidney disease.
Differential diagnosis:
- Infectious enteritis: this does not usually cause stenoses.
- Radiation enteritis: however, there is no history of radiotherapy.
Management:
Urgently contact referring physician and inform of findings.
The patient will likely require surgical management.
Case 1 Your Answer:
Case 2
Case 2 Model Answer:
Findings and interpretation:
- The left maxillary sinus is filled with fluid, appearing hyperintense on T2 and isointense on T1, with a small pocket of air in an anti-dependent position. The mucosal lining is enhancing on the post contrast images.
- There is an ill-defined, fungating mass arising within the base of the skull, centred on the clivus. The mass is markedly hyperintense on the T2 weighted images and iso-intense on T1.
- The mass extends into the pre-pontine cistern and exerts a modest degree of mass effect on the pons and midbrain, with minor displacement of the basilar artery. It also shows extension into the apex of the petrous bone and abuts the left internal carotid artery with no invasion.
- The mass shows heterogeneous enhancement on the post-contrast sequences.
- The mass exhibits modest diffusion restriction with somewhat bright signal on DWI and corresponding low ADC values.
The findings represent inflammation of the left maxillary sinus, which is responsible for the patient’s symptoms. Incidentally found is a midline, somewhat aggressive neoplastic bony mass, which appears to be slow growing.
Principal diagnosis:
Acute maxillary sinusitis with incidental clivus chordoma
Differential diagnosis:
Sinus:
- Mucocele
- Fungal sinusitis
Skull base lesion
- Giant cell tumour
- Chondrosarcoma
Management:
Recommend discussion at neurosurgery MDT regarding obtaining a biopsy and possible resection for the skull base lesion.
Case 2 Your Answer:
Case 3
Case 3 Model Answer:
Findings and interpretation:
Chest radiograph:
- There is airspace opacification in the right lower and middle lung zones.
- There are no pleural effusions.
CT:
- There is widespread peribronchovascular and peripheral subpleural nodular consolidation in both lungs.
- There are patchy and randomly distributed areas of ground glass opacification.
- In the right lung base there are lesions of crescent shaped consolidation surrounding a central areas of ground glass opacification, showing the so-called ‘atoll sign’.
Pertinent negative findings:
- There are no significantly enlarged mediastinal lymph nodes/ pleural effusions.
Incidental:
- Incidentally noted left mastectomy.
There is chronic, migrating consolidation involving both lungs. It is likely auto-immune / cryptogenic in nature.
Principal diagnosis:
Cryptogenic organizing pneumonia
Differential diagnosis:
- Chronic eosinophilic pneumonia (usually more peripheral consolidation; no history of eosinophilia)
- Bronchopneumonia (no acute symptoms of infection; unusual distribution of disease for this diagnosis)
- Atypical and fungal lung infection
Management:
Alert the referring physician of findings and recommend corticosteroid administration.
Follow up imaging by HRCT to monitor response to treatment.
Case 3 Your Answer:
Case 4
Case 4 Model Answer:
Multi-system Sarcoidosis
Findings and interpretation:
Feet radiograph:
- There is erosion of the tufts of the distal phalanges involving multiple toes bilaterally.
- There is severe erosive arthropathy of the PIP joint of the right third toe causing significant bony destruction and subluxation.
- There is subtle lace-like change in the left first toe distal phalanx.
Hands radiograph:
- There is erosion of the distal tuft of the distal phalanx of the right thumb, as well as severe erosive arthropathy of the DIP joint of the right thumb with bony debris and subluxation.
- There is peri-articular calcification at the DIP joint of the left thumb, with subtle bony lace-like change on both sides of the joint.
- There is dislocation of the PIP of the left fourth finger.
- There are multifocal lucencies in the hands bilaterally, bony remodelling of the right 4th middle phalanx, and juxta-articular erosion at the right 4th metacarpo-phalangeal joint.
MRI brain:
- There are FLAIR and T2 patchy hyper-intensities within the deep and sub-cortical white matter.
- There is marked, diffuse, nodular pachy and lepto-meningeal thickening; this shows avid enhancement on the post-contrast sequences.
Pertinent negative findings:
Hands and feet:
- No osteopaenia.
Brain:
- Relative sparing of the pituitary gland and hypothalamus, as well as the mid-brain / cranial nerves.
The constellation of findings represent a multi-system disease involving the CNS and musculoskeletal system, with the features of a granulomatous disease. This is causing white matter angiitis and active meningeal infiltration/inflammation in the CNS and erosive / destructive arthropathy in the hands and feet.
Principal diagnosis:
Multi-system sarcoidosis
Differential diagnosis:
- Multi-system tuberculosis.
- Diffuse metastatic spread from unknown primary (this is extremely unlikely due to the pattern of disease and sites of involvement).
Management:
- Search for other sites of involvement, especially pulmonary; chest radiograph / CT chest may be performed.
- Gallium scan may be performed to search for active disease.
- Correlate with clinical/lab tests such as serum ACE; biopsy from an adequate site may be performed.
- Discuss at connective tissue disease MDM.
Case 4 Your Answer:
Case 5
Case 5 Model Answer:
Findings and interpretation:
- The appendix is dilated, filled with fluid, and shows a grossly thickened and enhancing wall; there is surrounding fat stranding and thickening of the adjacent fascia. This represents inflammation of the appendix.
- The cervix is enlarged and hypo-enhancing.
- There is an irregular, round, hypodense small lesion in segment VI of the liver, which shows hypo-enhancement on the portal venous phase images.
There is inflammation of the appendix, indicating appendicitis. There are unrelated findings in the cervix, which most likely represent a malignant process. The lesion in the liver also shows malignant characteristics.
Pertinent negative findings:
- No suspicious pelvic lymph nodes detected.
- No bone or lung lesions suspicious for metastases on visualized images.
- No evidence of appendix perforation / abscess.
Principal diagnosis:
Acute appendicitis, with incidentally detected cervical carcinoma and focal liver metastasis.
Differential diagnosis:
The differential for the cervix would be cervicitis; however, there is no evidence of surrounding inflammation.
The differential for the focal liver lesion includes liver abscess / hepatoma.
Management:
Alert referring physician of the urgent findings (appendicitis).
Recommend liver MRI as further management and OBGYN referral.
Case 5 Your Answer:
Case 6
Case 6 Model Answer:
Findings and interpretation:
Non-contrast brain CT:
- There is hyperdense material in the interpeduncular and suprasellar cisterns, extending into the 3rd ventricle; this indicates subarachnoid haemorrhage.
- The 3rd ventricle is dilated, as well as minimal dilatation of the lateral ventricles; this indicates obstructive hydrocephalus caused by the haemorrhage.
CT angiogram:
- There is a medium sized aneurysm of the basilar tip, at the site of the previously mentioned subarachnoid haemorrhage.
- There is also another similar sized aneurysm of the M1 segment of the right MCA, and a third smaller aneurysm at the right M1 bifurcation.
Pertinent negative findings:
- No active extravasation from the basilar tip aneurysm on the angiogram.
- No intraparenchymal haemorrhage.
The findings represent subarachnoid haemorrhage caused by a ruptured basilar tip aneurysm, in a patient with multiple intracranial aneurysms.
Principal diagnosis:
Aneurysmal subarachnoid haemorrhage.
Differential diagnosis:
None.
Management:
Immediately alert referring physician of findings.
Recommend neuro-interventional referral for possibility of endovascular management of the aneurysms by coil embolisation.
Case 6 Your Answer:
Case 7
Case 7 Model Answer:
Findings and interpretation:
CT:
- There is nodular, marked, circumferential pleural thickening on the right side, with similar marked thickening of the pleural fissures. This appears to be encasing the right lung.
- There is significant volume loss of the right lung.
- There is a moderate right sided pleural effusion.
- There are multiple hypodense splenic lesions.
Pertinent negative findings:
- There is no mediastinal lymphadenopathy.
- There are no calcified pleural plaques.
The findings represent a malignant process originating from the pleural, with probable splenic metastases.
Principal diagnosis:
Pleural mesothelioma
Differential diagnosis:
- Pleural metastases from unknown primary (this is highly unlikely)
Management:
Alert referring physician of diagnosis.
Refer for discussion at pulmonary MDT to discuss further imaging (staging abdomen pelvis CT) and image guided biopsy of the pleura and splenic lesions.