The abdominal aorta is the portion of the aorta that carries blood flow to the abdomen, pelvis, and legs. Sometimes the walls of this part of the aorta weaken and bulge in one area. If the Abdominal Aortic Aneurysm becomes large or ruptures, surgery is necessary. The tests needed to determine an AAA is a CT Scan of the abdomen, MRI, or abdominal ultrasound, EKG, or Chest X-Ray. Learn more here.