Coloured computed tomography (CT) scan of the abdomen of 64 year old male patient who has been treated for an abdominal aortic aneurysm. The aorta is the body's main artery. A stent (mesh tube, white) has been placed in the aorta to strengthen its walls. An aneurysm is a weakening of the walls of a blood vessel, leading to swelling and rupture. In the aorta, such rupturing is swiftly fatal. Surgery is needed before a rupture to repair the aorta.