Abdominal aortic Aneurysm [AAA]

Pathology

Atherosclerotic changes leads to aneurysmal dilatation of abdominal aorta
Calcification of wall can occur
Complications:
- Rupture with extravasation of blood chronic or acute
- Erosion of the adjacent vertebral bone can occur
- Thrombus can form in the lumen
- Emboli to distal vessels from atheromatous plaques

The abdominal aorta was opened along the posterior wall revealing severe atherosclerosis. The anatomical features are obscured by ulcerated plaques and superimposed blood clots.

A medium size aneurysm arises from the aorta between the renal and inferior mesenteric arteries.

What are the anticipated imaging findings of abdominal aortic aneurysm?

Widened aortic lumen

Abdominal aorta > 3 cm

Additional findings

Thrombus within aneurysm
Calcification
- Aneurysm wall
- Surface of thrombus
- Within thrombus
Complications
- Rupture
- Compression and or erosion of adjacent structures
- Embolic to distal extremities

Ultrasound showing findings of Abdominal Aortic Aneurysm

CT scan from another case with Abdominal Aortic Aneurysm

Note wall calcification of the aneurysm of aorta.

Ruptured Abdominal Aortic Aneurysm

CT without IV contrast shows abdominal aortic aneurysm (A) with high density blood (arrows) indicating rupture.