"Angiography" by magnetic resonance imaging: detailed vascular anatomy without ionizing radiation or contrast media.

: Using software to transform magnetic resonance imaging (MRI) tomographic data into three-dimensional projections, we have produced "angiograms" of the abdominal aorta in 18 patients with occlusive (15) and aneurysmal (3) disease. This information may be displayed to demonstrate flow, cross-sectional diameter, or aortic surface anatomy. To test the accuracy of the MRI studies, we compared them at selected points with the transected aorta and with routine aortograms. Relative cross-sectional diameter estimated by MRI was within 15% of measured aortic diameter in 14 of the 18 vessels and enabled correct detection of thrombus in 16. We conclude that MRI may accurately image the diseased abdominal aortic wall. In addition, an angiographic display format may aid in the interpretation of these studies. Although MRI is not likely to replace aortography, it could be used adjunctively to define aortic wall thickness and the presence of thrombus.