Model Answers
Case 1
Case 1 Model Answer:
Findings and interpretation:
- There is an area of mesenteric fat stranding at the root of the small bowel mesentery, with a thin surrounding capsule. This area surrounds the mesenteric vessels.
- There are multiple enlarged lymph nodes within the area of fat stranding, some of which show a hypodense surrounding halo.
Pertinent negative findings:
- There is no evidence of fibrosis or calcification
- There is no evidence of associated abdomino-pelvic malignancy.
The findings represent a non-specific, likely inflammatory process involving the small bowel mesentery.
Principal diagnosis:
Mesenteric panniculitis
Differential diagnosis:
- Lymphoma
- Metastatic spread of unidentified malignancy
Management:
Recommend discussion at gastro-intestinal MDT.
Recommend periodic follow up imaging, as this condition may develop into lymphoma.
Case 1 Your Answer:
Case 2
Case 2 Model Answer:
Findings and interpretation:
- There are numerous, scattered T2 and FLAIR hyperintense lesions in the periventricular white matter, as well as the subcortical white matter in a generalised distribution. These lesions are also seen in the brainstem, cerebellar peduncles, cerebellar hemispheres, and internal and external capsules.
- The lesions are most concentrated at the calloso-septal interface, where they have an elliptical shape with an orientation perpendicular to the lateral ventricles.
- A few of the lesions show mild, eccentric, open ring enhancement (for example one in the left anterior peri-ventricular white matter). This enhancement pattern is characteristic of de-myelination.
Pertinent negative findings:
- The lesions do not show significant peri-lesional oedema.
The findings represent a de-myelinating process in the brain. The enhancing lesions represent active de-myelination.
Principal diagnosis:
Multiple sclerosis
Differential diagnosis:
- Acute disseminated encephalo-myelitis (this is unlikely as it does not show the expected distribution pattern of ADEM)
- Neurovasculitis (This is unlikely as the distribution of disease is typical of multiple sclerosis)
Management:
Compare with previous imaging if available.
Recommend discussion at neurology MDT with regards to active inflammation and medical treatment options.
Case 2 Your Answer:
Case 3
Case 3 Model Answer:
Findings and interpretation:
- There is high STIR and low T1 marrow signal intensity in the proximal half of the femur, with a fracture of the proximal third of the shaft of the femur.
- There is a large, heterogeneously T2 hyperintense mass arising from the fractured proximal third of the bone, with extension into the quadriceps and adductor muscle groups.
- There is high STIR signal in the surrounding subcutaneous fat, indicating oedema.
Pertinent negative findings:
- The distal half of the bone is normal.
The findings represent pathological fracture of the proximal third of the femur due to an aggressive bony lesion. This is most likely a primary bone malignancy.
Principal diagnosis:
Osteosarcoma of the femur with pathological fracture
Differential diagnosis:
- Ewing’s sarcoma
- Other soft tissue sarcoma
Management:
Alert referring physician of findings.
Recommend staging CT thorax abdomen pelvis.
Recommend bone scan to search for multiple bone involvement.
Recommend discussion at sarcoma MDT regarding image guided biopsy for histopathological diagnosis (this should be planned with the orthopaedic surgeons in order to avoid biopsy tract seeding in tissue that will not be resected). It may be more appropriate to refer to a tertiary sarcoma centre for further management.
Case 3 Your Answer:
Case 4
Case 4 Model Answer:
Findings and interpretation:
Chest radiograph:
- There is mediastinal and bilateral hilar lymph node eggshell calcification.
- There is bilateral widespread reticulonodular opacities in the lungs, with a predominantly midzone distribution.
CT:
- In addition to the calcified lymph nodes noted on the chest radiograph, there are bilateral perihilar stellate mass-like opacities with central, coarse calcifications.
- There is a surrounding fibrotic reaction and architectural distortion.
- There are scattered, spiculated nodules throughout both lungs.
- There is generalised nodular thickening of the fissures and interlobular septae.
- There is bilateral pleural thickening.
The findings represent a chronic, interstitial lung disease.
Principal diagnosis:
Conglomerate fibrosis on a background of sarcoidosis
Differential diagnosis:
- Silicosis with progressive massive fibrosis
- Coal worker’s pneumoconiosis with progressive massive fibrosis
Management:
Review any previous imaging if available.
Recommend tissue biopsy for histological diagnosis if diagnosis not already known.
Refer for pulmonary MDT discussion with regards to further management (lung transplant may be indicated).
Case 4 Your Answer:
Case 5
Case 5 Model Answer:
Findings and interpretation:
- There is bony destruction and periosteal reaction at the antero-superior vertebral body corner, as well as narrowing of the L3/L4 intervertebral disc space.
- There is a large paraspinal collection adjacent to the site of vertebral destruction on the right side, with calcified foci seen within the collection. The collection extends into the right ilio-psoas muscle.
- There is a large left sided ilio-psoas collection.
- There are a few retroperitoneal and left common iliac enlarged lymph nodes with a necrotic centre.
- There is moderate right sided hydronephrosis.
Pertinent negative findings:
- There is no obvious extension of the abscesses into the spinal canal / spread into the epidural space.
Incidental:
- Two nodules are seen in the lung bases, one on each side.
The findings represent an indolent spondylodiscitis, giving rise to large adjacent abscesses. The right ureter is involved in the inflammatory process in its proximal segment, causing obstructive nephropathy.
Principal diagnosis:
Tuberculous spondylodiscitis
Differential diagnosis:
- Brucellosis spondylodiscitis
Management:
Review chest radiograph for evidence of post-primary pulmonary tuberculosis.
Contact referring physician and inform of findings; recommend placing the patient in isolation.
Recommend drainage of abscesses and collecting samples for culture and sensitivity.
Case 5 Your Answer:
Case 6
Case 6 Model Answer:
Findings and interpretation:
- There is a reniform mass in the abdomen, with outer and inner hypoechoic layers, and a hyperechoic layer sandwiched in between.
- It shows a target appearance on the transverse images.
- There is internal colour doppler flow.
- There are multiple enlarged lymph nodes within the mass.
- Both kidneys are visualised separate to the mass.
The findings represent an intussusception, with one loop of bowel invaginating into the other. The lymph nodes are likely the causative lead point in this case.
Diagnosis:
Intussusception
Differential diagnosis:
None
Management:
Urgently contact referring physician and inform of findings.
Hydrostatic or pneumatic reduction may be planned with paediatric surgeon.