Differentiation of aortic pseudoaneurysm from ductus diverticulum is critical, particularly in the trauma setting. A traumatic aortic pseudoaneurysm is a surgical emergency whereas a ductus diverticulum is a normal anatomic variant.
The following are differentiating features:
Aortic pseudoaneurysm
- location: often seen along the inferior surface of the aortic isthmus 1
- forms an acute angle with the aortic wall
- calcification not present
- other supportive findings: signs of regional traumatic injuries such as an intimal flap or hematoma nearby within the aortic wall and/or mediastinum
Ductus diverticulum
- location: usually found at the anteromedial aspect of the aortic isthmus 2
- often forms a gentle, obtuse angle with the aortic wall
- calcification: an important differentiating point when present
- absence of other supportive findings