We propose to utilize fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging co-registered with structural computerized tomography (CT) images for the in vivo localization and quantification of vascular inflammation in patients with AAA in order to determine whether increased inflammation within the walls of the aneurysm correlates with rapid enlargement of AAA (change in aneurysmal diameter within 6 months), symptoms, thrombosis, or intervention for ruptured, leaking, rapidly expanding, or painful AAAs.