Abdominal #19

A 79-year-old female patient:
– Presented with abdominal pain, nausea, vomiting
– Previous history of cholecystitis and pancreatitis
– Laboratory findings:
*Elevated C-reactive protein and white blood cell levels

What do you see?

Pneumobilia (arrow)

Cholecystoduodenal fistula (red arrow)
Gastric (blue arrow) and duodenal (green arrow) distension

Gallstone located in the proximal jejunal segment (red arrows)
Gastric distension (blue arrows)

What is your diagnosis?

Gallstone ileus


Abdominal CT images obtained two years earlier show that the gallstone is in the gallbladder (arrows).

Teaching points:

* Gallstone ileus is a cause of mechanical small bowel obstruction that generally affects the elderly and has high mortality. It is a rare complication of chronic cholecystitis. It develops when a gallstone passes through a cholecystoenteric fistula leading to small bowel obstruction.

* Gallstones most commonly become impacted in the distal ileum.

* The classical imaging findings on abdominal radiographs form Rigler triad: pneumobilia, small bowel obstruction, and ectopic radio-opaque gallstone

* CT is the most frequently used imaging modality for the diagnosis as it demonstrates the rim-calcified or total-calcified ectopic gallstone, abnormal gallbladder with air collection, presence of air-fluid level, biliary-enteric fistula, and transition point of small bowel obstruction. However, only a minority of gallstones are calcified. Therefore, they may be overlooked in intestinal lumen, which may result in misdiagnosis. Multiplanar reformatted CT images can be helpful to locate the migration site of the ectopic stones.

* Treatment: Surgery with removal of gallbladder stone is the definitive treatment.

In our case, the patient underwent surgery. Enterotomy with gallstone removal was performed. According to the operation note, the gallstone was located in the jejunum 20 cm distal to the ligament of Treitz.

Abdominal #18

75-year-old female:
– Day 4 post Whipple procedure
– Ongoing abdominal pain with increased inflammatory markers and slightly increased lactate levels

What do you see?

– Post-operative changes following partial pancreatectomy and duodenojejunostomy (partially shown)
– Prominent mesenteric nodes
– Partially occlusive thrombus of the superior mesenteric vein (best seen on axial slice) extending to a large jejunal branch (seen on coronal slice)

What is the most likely diagnosis?

Partial SMV occlusion as a complication to recent Whipple procedure

Musculoskeletal #31

8-year-old patient:

– With a chronically painful right knee and ankle

Clinical information:

– Patient with no relevant clinical history
– Parents mention a difficulty when running, the patient trips very easily and sometimes struggles to use the right leg. The right leg is often painful

Showing the X-ray right knee and the pelvis

What do you see?

X-ray right knee

Eccentric, lytic bone lesions with sharp margins
No periosteal reaction
Ground-glass matrix of the lesion in the right tibial diaphysis
Soap-bubbly appearance of the lesion in the femoral diaphysis

X-ray pelvis

Expansile bone lesion with ground glass matrix in the right femoral neck, extending into the proximal diaphysis
Slight varus deformity of the femoral neck
Similar lesion in the right iliac wing/acetabular region

A CT was performed:

Showing X-ray of both feet.

What do you see?

Expansile bone lesion with ground glass matrix involving the 1st metatarsal and proximal and distal phalanges of the left foot
Soap-bubbly lesions of the talus and 5th metatarsal

What is your diagnosis?

Imaging findings:

– Multiple bone lesions with benign appearance
– Expansile lesion with ground-glass matrix in the femoral neck virtually pathognomonic for fibrous dysplasia
– Genetic testing could not reveal mutations of the GNAS gene: no syndromic association in this patient

Teaching points

Teaching points:

Benign bone lesions
– Usually central in bone
– Varying degrees of expansion
– Ground-glass matrix (mildly sclerotic)
– Lack of aggressive features (no periosteal reaction, no cortical breakthrough or soft tissue mass)
Aetiology: developmental dysplasia
Fibrous dysplasia is polyostotic in 15–20%, often in syndromic association (mutations of the GNAS gene)
– McCune-Albright syndrome (in combination with endocrine dysfunctions)
– Mazabraud syndrome

Abdominal #17

Known patient with recently diagnosed poorly differentiated vaginal carcinoma with staging FDG PET/CT study. What is the study showing?

What do you see?

– A hypermetabolic lower vaginal lesion representing the known vaginal neoplasm associated with a larger hypermetabolic uterine body neoplastic lesion suggesting synchronous malignant process
– Multiple hypermetabolic enumerable bilateral lung deposits associated with a single right lower para-tracheal nodal deposit

Head and Neck #13

What do you see?

Labyrinthitis Ossificans

Ossification of the membranous labyrinth, high-density bone deposition involving all the cochlear turns.

This usually occurs as a complication of suppurative labyrinthitis, either due to otomastoiditis or meningitis. Other causes include trauma, autoimmune diseases, and surgery.

Abdominal #16

What do you see on the following images?

Click here to see the answer

TB cervical lymphadenitis

Mild progression in size of multiple necrotic lymph nodes in bilateral supraclavicular, axillary regions, at all anterior and posterior cervical chain (more prominent at right side lower anterior cervical chain)

Musculoskeletal #30

38-year-old with left knee pain.
Showing multiple images:

Left knee X-ray:

STIR:

What is the most likely diagnosis?

Enchondroma

* Relatively common intramedullary cartilage neoplasms with benign imaging features
* Constitute ~5% (range 3–10%) of all bone tumors and ~17.5% (range 12–24%) of benign bone tumors

What are the radiological features?

Radiological features

* Narrow zone of transition
* Sharply defined margins
* Chondroid calcification, however, purely lytic in the hands/feet
* Sometimes expansile – more commonly in hands/feet
* Mild endosteal scalloping
* Do not “grow” through cortex (unless pathologic fracture)
* No bone destruction
* No periosteal reaction
* No soft tissue mass

What may be the complications?

Complications

* Pathological fracture
* Malignant transformation into chondrosarcoma

Differential diagnosis includes..

Differential diagnosis

* Bone infarct
* Chondrosarcoma
* Intraosseous ganglion

References

* Murphey MD, Flemming DJ, Boyea SR et-al. Enchondroma versus chondrosarcoma in the appendicular skeleton: differentiating features. Radiographics. 18 (5): 1213-37. Radiographics (abstract) – Pubmed citation
* Walden MJ, Murphey MD, Vidal JA. Incidental enchondromas of the knee. AJR Am J Roentgenol. 2008;190 (6): 1611-5. doi:10.2214/AJR.07.2796 – Pubmed citation
* Douis H, Saifuddin A. The imaging of cartilaginous bone tumours. I. Benign lesions. Skeletal Radiol. 2012;41 (10): 1195-212. doi:10.1007/s00256-012-1427-0 – Pubmed citation
* Mulligan ME. How to Diagnose Enchondroma, Bone Infarct, and Chondrosarcoma. (2019) Current problems in diagnostic radiology. 48 (3): 262-273. doi:10.1067/j.cpradiol.2018.04.002 – Pubmed

Musculoskeletal #29

30-year-old male:

· Persistent pain in his right ankle, for a year long, a synovial mass was demonstrated on ultrasound. · Ankle MRI was performed

What do you see?

Pigmented villonodular synovitis (diffuse articular form)

* Benign proliferative condition affecting the synovial membrane. Most commonly monoarticular
* MRI: Mass-like synovial proliferation with lobulated margins and articular erosions
– Signal -> T1: low-intermediate ; DPFS/STIR: heterogeneous with areas of high signal ; GE: blooming artifact ; T1GD: variable enhancement.

What is the differential diagnosis?

Differential diagnosis includes:
* Scarring – capsulitis
* Siderotic synovitis
* Synovial sarcoma