[Contribution of imaging to the study of aortic aneurysms]

All aortic aneurysms require a positive diagnosis, a differential diagnosis and an assessment of extension. Several exploratory methods can be contemplated. In patients with warning symptoms, conventional radiology may point to the diagnosis. The reference method remains retrograde aortography which may be either conventional and seriographic or, better, radiocinematic with orthogonal projections and, if possible, digital. The site and morphology of the aneurysm, and in particular its inner channel are thus demonstrated. Computerized tomography is less invasive and usually of great value, notably for the horizontal, thoracic and abdominal aorta, not only to confirm the diagnosis but also to determine the size of the inner channel, parietal thrombi and aortic walls, as well as relations with nearby structures. Other, totally non-invasive methods are widely utilized to explore aortic aneurysms. These are ultrasonography and its variants (notably Doppler-echocardiography and the transoesophageal route), and magnetic resonance imaging which provides three-dimensional and anatomical views of the vessel. These last two examinations alone usually confirm and outline the aortic aneurysms. They must therefore be utilized as first-line examination, arteriography it is various forms being reserved for emergencies or special cases.