Computed tomography in the decision for carotid endarterectomy

Abstract

Computed tomographic angiography (CTA) is being used more frequently in the decision for the carotid endarterectomy. The accuracy of CTA to differentiate between moderate and severe occlusions of the internal carotid artery has been evaluated in this study. After color-flow duplex (CFD) scanning to determine the severity of the stenosis, contrast-enhanced spiral CTA was performed in 60 carotid arteries of 30 patients. 2-D or 3-D time-of-flight MRA techniques and gadolinium enhancement were also used to measure stenosis. Accuracy for moderate, severe and occluded stenoses was calculated. Internal carotid artery stenosis was classified as completely occluded in four, severe in 27, moderate in 25 and mild in four by CFD. There were five total occlusions, and 19 severe, 30 moderate and six mild stenoses by CTA. The overall accuracy of CTA to CFD was 84%, and was 92% and 75% for moderate and severe stenoses, respectively. CTA has identified calcification and ulceration of the plaque. By MRA there were 2 total occlusions, and 33 severe, 19 moderate and six mild stenoses. The overall accuracy of MRA to CFD was 80%, and was 70% and 94% for moderate and severe stenoses, respectively. While MRA is now routinely used to confirm the results of CFD before surgery, the CTA may in time replace the MRA because it better identifies plaque morphology, ulceration and tight stenoses.