CT angiography versus intraarterial digital subtraction angiography for assessment of aortoiliac occlusive disease

OBJECTIVE. The purpose of this study was to evaluate the accuracy of CT angiography (CTA) with a single helical acquisition for assessment of stenoses and occlusions of the iliac arteries. SUBJECTS AND METHODS, In our prospective study, intraarterial digital subtraction angiography and TV CTA were performed from the suprarenal aorta to below the femoral bifurcation in 30 patients with vascular occlusive disease. Maximum-intensity-projection images in multiple views were also obtained. The accuracy of CTA with and without analysis of axial images was determined. RESULTS, Sensitivity and specificity of CTA were 100% for iliac artery occlusions with a confidence interval 85-100% and 97-100%, respectively. When axial scans were interpreted, 14 of 15 high-grade (>75%) stenoses were recognized. Sensitivity and specificity of CTA were 93% (range, 68-100%) and 99% (range, 97-100%), respectively. When maximum intensity projections alone were analyzed, sensitivity for the diagnosis of 15 high-grade stenoses was only 53% (range, 27-79%) because calcified plaques obscured six stenoses. CONCLUSION. CTA accurately reveals iliac artery occlusions. Observers of CT angiograms may overlook short stenoses in rare instances. Calcified plaques limit the use of maximum-intensity-projection images.