Frontal X-ray and CT angiogram (right) of the thorax of a 68-year-old patient presenting with pain in the chest. The chest X-ray shows a deformation of the right cardiovascular contour. There is an aneurysm of the ascending thoracic aorta. Aneurysms are localised, blood-filled balloon-like bulges in the wall of a blood vessel. They form when the wall is weakened by disease or another cause.