Diagnostic Value of Spiral-CT Angiography in Comparison with Digital Subtraction Angiography Before and After Peripheral Vascular Intervention

Abstract

To evaluate spiral-computed tomography (CT) angiography in primary diagnosis and/or in noninvasive follow-up after vascular intervention, we compared spiral-CT angiography and conventional angiography before and after vascular intervention. Helical-CT exam inations before and after percutaneous transluminal angioplasty (PTA) or stent implan tation were performed in 10 patients (mean age 63 years) with symptomatic peripheral arteriosclerotic disease. Stenoses were located in the iliac, femoral, or popliteal artery. CT examinations were done with a spiral-CT in double detector technique (CT Twin, Elscint). The parameters were as follows: slice thickness: 5.5 mm, increment: 2.7 mm, pitch: 1.5, contrast medium: 150 mL, flow rate: 2.5 mL/second, delay: 30 seconds. For evaluation, transverse planes as well as maximum intensity projections and 3-D reconstructions were used. The possible scan length reached from the aortic bifurcation down to about 10 cm below the ankle trifurcation. Preinterventional digital subtraction angiography (DSA) was superior to CT angiography (CTA: 94%, maximum intensity projection [MIP] alone: 65%), although high-grade stenoses were detected by both methods. After intervention, a resolved stenosis and improved peripheral flow could be detected by helical-CT as well as by intraarterial angiography in every patient (100%). In the primary diagnosis of vascular changes, intraarterial DSA remains the method of choice. Nevertheless, spiral-CT angiography shows comparable results after percutaneous intervention and becomes a noninvasive alternative in the postinterventional follow-up.