MR angiography: supra-aortic vessels.

Magnetic resonance angiography (MRA) has become an imaging modality which comprises various techniques based on two concepts: methods relying on the natural flow effects, the time-of-flight and phase-contrast technique, either in two- or three-dimensional acquisition mode, and the more recently developed contrast-enhanced (CE) MRA methods. The main indications for evaluation of the supra-aortic vessels are, firstly, the grading of carotid artery stenoses caused by an atherosclerotic process, and secondly, the evaluation of dissections of the cervical arteries because this disease plays an important role as a cause for stroke especially in younger patients. The various MRA techniques in their application to the main pathologies encountered at the supra-aortic vessels are presented, and recent developments in the promising field of CE MRA are discussed.