Prospective comparison of CT angiography of the legs with intraarterial digital subtraction angiography

Abstract

Objective: The aim of this study was to determine the accuracy of CT angiography (CTA) with a single spiral acquisition for the diagnosis of arterial stenoses and occlusion in patients with peripheral vascular occlusive disease.

Subjects and methods: In a prospective study, intraarterial digital subtraction angiography and i.v. CTA from the groin to the lower calves were performed on 50 patients with vascular occlusive disease. Maximum-intensity-projection images in multiple views were produced. The accuracy of CTA with and without analysis of the axial scans was determined with digital subtraction angiography as the standard.

Results: The sensitivities of CTA were 100% for the diagnosis of femoral artery occlusion, 100% for the detection of popliteal artery (including tibial-peroneal arterial trunk) occlusion, and 94% for the detection of tibial artery occlusion. The specificities were 100%, 99%, and 98%, respectively. When maximum-intensity-projection images were interpreted without axial scans, sensitivities were 98%, 85%, and 92% and specificities were 100%, 99%, and 97%, respectively. For the accurate grading of high-grade (75-99%) stenoses of the superficial femoral artery and the popliteal artery (including tibial-peroneal arterial trunk), the sensitivities of CTA were 88% and 73% and the specificities were 94% and 100%, respectively. When maximum-intensity-projection images alone were used, the sensitivities for the correct grading of high-grade stenoses were 58% and 36% and the specificities were 99% and 100%, respectively.

Conclusion: CTA from the groin to the lower calves is feasible, and the short examination time is a significantly advantage over the time required for other noninvasive techniques. CTA is particularly accurate in the depiction of femoral artery occlusions. Maximum-intensity-projection images are useful, but analysis of axial scans is more accurate for the grading of arterial stenoses. The results of CTA are encouraging enough to warrant further studies. A CTA protocol covering the pelvic and pedal vessels remains to be established and evaluated.