Magnetic resonance angiography.

Magnetic resonance imaging allows the visualization of vascular structures without the use of contrast agents. With three-dimensional imaging techniques, based on gradient echo sequences, up to 128 slices can be acquired within a maximum acquisition time of 21 minutes at a spatial resolution of approximately 1 mm. This allows the carotid arteries and major intracerebral vascular structures to be displayed. From the primary three-dimensional data set, projective images at arbitrary projection angles can be calculated. This technique is extremely helpful for assigning spatially complex vascular structures and identifying vascular disease. As a result of rapid technologic advances in magnetic resonance angiography, it is now necessary to assess its clinical utility for identifying atherosclerotic stenoses, aneurysms, and arteriovenous malformations. Limited experience to date has shown that magnetic resonance angiography, because of its high sensitivity to these vascular diseases, may play a clinically important role as a screening method.