[Magnetic resonance angiography of supra-aortic arteries]

MR angiography of the carotid system was found to be readily applicable due to the laminar and fast flow conditions in the supra-aortic arteries. Time-of-flight methods are superior to phase-contrast measurements for the investigation of atherosclerotic lesions. Recent developments in sequence design enable improvement of the MR angiographic results with respect to correct staging of stenotic alterations. Two-dimensional acquisitions are preferred in slow flow conditions with the disadvantage of decreased resolution, in-plane saturation effects, and poststenotic signal voids. In 3D MR angiography, the major advantage is improved resolution, although the saturation effects within the measurement volume must be compensated for either by sequential acquisition of multiple thin volumes or by the application of asymmetric excitation pulses. In a prospective trial with 50 patients, the advantages of a new type of rf-pulse (TONE) are demonstrated.