Abdominal #21

86-year-old patient:

– With sudden collapse

Clinical information:

– Patient known with infrarenal aortic aneurysm
– Sudden collapse at home
– Transfer to the hospital with ambulance

Axial and coronal slices of an abdominal CT in 2019 show a tortuous abdominal aorta with aneurysmal dilatations and eccentric thrombus. There is a thrombosed saccular component at the level of the aortic bifurcation (arrow)

CT at presentation:

What is the diagnosis?

Diagnosis:

Ruptured aortic aneurysm
* known infrarenal aortic aneurysm
* massive retroperitoneal hematoma extending into the posterior pararenal and perirenal compartments
* active contrast extravasation
Point of weakness: saccular aneurysmal component

Teaching points:

This case did not show a classic sign of pending rupture; however, a clear point of weakness was retrospectively identified (the saccular aneurysmal component at the aortic bifurcation)
Radiological signs of pending rupture:
* !! High attenuating crescent (= acute haematoma within the mural thrombus or aneurysmal wall)
* Focal discontinuity of intimal calcification and ‘tangential calcium sign’
* ‘Draped aorta sign’, present when
* The posterior aortic wall is unidentifiable as a distinct line
* The posterior aorta follows the contour of the spine on one or both sides
Reference: CT signs of pending aortic aneurysm rupture, J.P. Heiken, radiologyassistant.nl
https://radiologyassistant.nl/abdomen/aorta/aneurysm-rupture

Head and Neck #14

What do you see in the following images?

Click here to see the answer

Nasolabial cyst
Right nasolabial lesion with remodeling of the maxillary alveolus bone. On MRI it shows high signal intensity on both T1- and T2-weighted images with no signal suppression on the T2 FLAIR with Fat saturation sequence.
Differential Diagnosis:
Nasolabial cyst with hemorrhage
Epidermal inclusion cyst
Dermoid cyst
Dentigerous cyst

Abdominal #20

61-year-old female:
– With elevated ALT, AST, and bilirubin

What do you see?

What do you see?

Wall thickening and enhancement of the gallbladder wall
Mild common bile and intrahepatic duct dilatation
Filling defect within the distal common bile duct

Diagnosis:

Choledocholithiasis

Musculoskeletal #32

53-year-old male:
– Persistent right shoulder pain, no movement limitations.
– No previous trauma.
– Shoulder MRI is performed

What do you see?

Click here to see more information

Quadrangular/Quadrilateral space syndrome
– Posteroinferior paralabral cyst (arrow) extending into the quadrangular space
– Teres minor mild fatty infiltration – atrophy (circle)
– Neurovascular compression syndrome of the posterior humeral circumflex artery (PHCA) and/or the axillary nerve or one of its major branches in the quadrangular space
– Multiple causes of compression: fibrotic bands, ganglion/cysts, aneurysms, tumours
– MRI may demonstrate atrophy and/or denervation edema of the teres minor and/or deltoid muscles
– Differential diagnosis: Parsonage-Turner sd, disuse atrophy

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.