An abdominal aortic aneurysm (AAA) occurs when the aorta, the main artery that carries blood away from the heart in the lower part of the body, weakens and bulges. Usually, no symptoms occur with an AAA. People at high risk for AAA include adults older than 65 years, people who smoke or used to smoke (especially men), and adults with a family history of AAA. AAAs can be fatal if they rupture and should be monitored for growth. Treating a nonruptured AAA is recommended in individuals without symptoms if the size of the aorta is larger than 5.5 cm for men and 5.0 cm for women, or if the aneurysm is growing rapidly.
Imaging tests are performed when an AAA is suspected. For the initial imaging, the following tests are usually appropriate: ultrasound of the aorta and abdomen, MR angiography —imaging of blood vessels—of the abdomen and pelvis with intravenous (IV) contrast; MR angiography of the abdomen and pelvis without and with IV contrast; MR angiography of the abdomen and pelvis without IV contrast; CT angiography of the abdomen and pelvis with IV contrast; and CT angiography of the abdomen and pelvis without and with IV contrast.
Tests that may be appropriate for the initial imaging are as follows: MRI of the abdomen and pelvis with IV contrast; MRI of the abdomen and pelvis without and with IV contrast; MRI of the abdomen and pelvis without IV contrast; CT of the abdomen and pelvis with IV contrast; CT of the abdomen and pelvis without IV contrast; and CT of the abdomen and pelvis without and with IV contrast.
For more information, see the Abdominal Aortic Aneurysm (AAA) page.