Computed tomography of aortoiliac atherosclerosis.

Twenty-three patients with atherosclerotic peripheral vascular disease underwent angiography and CT of the aortoiliac segment within a 72-hour interval. Examinations were evaluated for depiction of disease in the aortic and iliac segments in five categories: stenosis, plaque morphology, vascular ectasia, calcification, and other pathologic conditions. Angiography and CT were equally accurate in their depiction of the degree of aortic stenosis or occlusion and in identification of aortic ectasia. Angiography proved superior to CT in the display of plaque morphology in 57% of aortic lesions and 74% of iliac abnormalities. Angiography also showed clear superiority over CT in quantification of iliac stenosis in 75% of patients with abnormalities, as well as in identification of iliac ectasia. CT detected both intimal calcification and incidental disease or congenital abnormalities better than angiography, including an unsuspected chronic contained aortic rupture. Overall, CT compared favorably with angiography in the identification of all types of aortic disease but major disadvantages of CT were evident in the iliac segment because of vessel tortuosity or heavy calcification. CT cannot replace arteriography in detecting atherosclerotic disease of the aortoiliac segment but can help to clarify angiographic findings in selected groups of patients.