Findings and interpretation:

• There is a fluid filled sac with exhibiting high T2 signal and low T1 signal (indicating simple fluid contents) located at the postero-medial aspect of the knee with an extension between the medial head of gastrocnemius and semi-membranosus tendon.
• There is a branching, tubular structure within the medial head of gastrocnemius which shows surrounding high signal on the fluid sensitive series and intermediate signal within on the T1 series, associated with high signal intensity in the surrounding muscle indicating muscular oedema.
• There is a small knee joint effusion.

Negative findings:

• No complex signal / fluid-fluid levels in the cyst.
• The cyst does not show thick walls or internal debris / thick material.
• Normal signal and calibre of the popliteal vein.

Incidental:

• Linear, horizontal high T2 signal in the body of the medial meniscus, representing meniscal intrasubstance degeneration.

The findings represent an uncomplicated Baker’s cyst, and thrombosis of the intramuscular gastrocnemius vein which was likely caused by pressure effect or compression by the adjacent Baker’s cyst.

Principal diagnosis:

Baker’s cyst causing thrombosis of the gastrocnemius vein.

Differential diagnosis:

Semi-membranosus bursitis- this is typically more medial and superior than a Baker’s cyst.

Management:

Contact referring physician and inform of findings.

The patient might be started on anticoagulation to prevent spread of DVT into the truncal deep veins.

Findings and interpretation:

• There is marked thickening of the bowel wall at the ileocaecal junction and caecum, with mild surrounding fat stranding.
• There are multiple enlarged regional (right iliac fossa and peri-caecal) lymph nodes.

Incidental findings:

• There is mild bibasal lung scarring and pleural plaques in the right lower hemithorax.
• There is a well defined, low density lesion in the right adrenal gland, representing an adenoma.

The findings likely represent an inflammatory process involving the ileocaecal region.

Principal diagnosis:

Ileocaecal tuberculosis

Differential diagnosis:

• Infectious ileocolitis (common organisms include Yersinia, Campylobacter, and Salmonella)
• Caecal carcinoma
• Crohn’s disease

Management:

Alert referring physician of findings and recommend isolation as a potential case of tuberculosis.

Recommend chest radiograph / chest CT to search for changes of post-primary pulmonary tuberculosis.

Refer for gastro-intestinal MDT discussion with regards to further management (endoscopy may be indicated).

Findings and interpretation:

• There is a tubular structure in the centre of the abdomen with two layers of bowel wall, and mesenteric fat and vessels within. This structure appears continuous with the small bowel and represents telescoping of one segment of small bowel into the other.
• There is dilatation of the small bowel proximal to this segment, with no oral contrast media passing through it.
• There are gas foci in the bowel wall of the intussusceptum, indicating pneumatosis intestinalis.

Pertinent negative findings:

• No portal venous gas.

The findings represent an intussusception with ischemia of the intussusceptum.

Principal diagnosis:

Ileo-ileal intussusception

Differential diagnosis:

None

Management:

Perform contrast enhanced CT if the patient is still in the radiology department.

Urgently contact referring physician and inform of findings. This patient will likely require emergent laparotomy.

Eosinophilic granulomatosis with polyangiitis (Churg Strauss)

History:

31 year old man with a history of asthma and shortness of breath was found to have blood eosinophilia and positive p-ANCA.

Studies:

Chest radiograph

HRCT performed 1 month later

Findings and interpretation:

Chest radiograph:

• There is patchy bilateral airspace opacification in an upper and mid lung zone distribution.

CT:

• There is multifocal bilateral ground-glass opacification, with a peripheral distribution.
• There are scattered, bilateral nodular/lobular consolidations, also in a peripheral distribution.
• The distribution is different to that seen on the previous radiograph, with the lower lung zones more involved on the later scan.
• There is some interlobular septal thickening.
• Bilateral moderate pleural effusions.

Pertinent negative findings:

• There is no lung cavitation.
• No significant mediastinal lymphadenopathy.
• The paranasal sinuses are normal.

The findings represent a chronic, migratory/transient pulmonary process. Asthma and eosinophilia in the history provided suggest that this is an inflammatory / allergic disease. Positive p-Anca suggests vasculitis.

Principal diagnosis:

Eosinophilic granulomatosis with polyangiitis (Churg Strauss)

Differential diagnoses:

• Chronic eosinophilic pneumonia (consolidations tend to be more homogeneous and peripheral (reverse bat-wing distribution).
• Cryptogenic organizing pneumonia (Appearances can be identical, but clinical data is less suggestive of this condition).
• Wegener’s Granulomatosis (cavitation is a feature, and more mass-like consolidation is encountered; c-Anca positive).

Management:

• Refer for discussion at pulmonary MDM
• Usually managed by corticosteroid administration

Polysplenia syndrome

Findings and interpretation:

CT:

• There are multiple small splenules in place of a single spleen.
• The third part of the duodenum fails to cross the midline, coursing instead to the right upper quadrant.
• All the small bowel loops are located in the right side of the abdomen, and the large bowel in the left.
• The pancreas is congenitally shortened with no tail, reflecting a semi-annular pancreas.

MRI:

• The multiple masses in place of the spleen show signal characteristics of splenic tissue.

Pertinent negative findings:

• No evidence of small bowel volvulus.
• Normal IVC.
• Normal liver and gallbladder.
• No dextrocardia.

Incidental:

• Small hypodense lesion in segment II of the liver has a benign appearance and likely represents a hepatic cyst.

The constellation of findings represent polysplenia syndrome, with semi-annular pancreas and midgut malrotation.

Principal diagnosis:

Polysplenia syndrome.

Differential diagnosis:

None.

Management:

Alert referring physician of findings.

This condition predisposes to small bowel volvulus and must be recorded in the patient’s file.  

Findings and interpretation:

Chest radiograph:

• There is marked mediastinal widening which obscures the cardiac silhouette. The trachea is displaced to the right. There is a large left sided pleural effusion.

CT:

• There is a large, heterogeneous, anterior mediastinal mass which extends to the superior mediastinum.
• It shows peripheral enhancement with large central areas of hypo-attenuation.
• There are enlarged posterior mediastinal lymph nodes.
• There are few punctate calcifications within the mass. There are no areas of fat density within the mass.
• The mass extends to and locally invades the sternum and anterior chest wall.
• There are bilateral pleural effusions and a pericardial effusion, as well as bilateral basal and left lower lobe consolidation.
• The SVC appears compressed and slit-like, yet it remains patent.

Pertinent negative findings:

• There are no enlarged abdominal / axillary / cervical lymph nodes.

This is a large, malignant mass with an aggressive appearance and extensive central necrosis.

Principal diagnosis:

Thymic carcinoma

Differential diagnosis:

• Lymphoma (Typically does not contain calcifications and does not invade bony structures)
• Teratoma (Usually contains some areas of fat density and larger calcifications)

Management:

Alert referring physician of findings.

Refer for discussion at oncology MDT with regards to CT guided biopsy of the mass for tissue diagnosis.