Accuracy of angiography and CT angiography of bifurcation of the carotid artery compared with the macromorphological correlate

Purpose: To compare the degree of carotid artery stenosis in angiography and CT angiography with the degree of stenosis measured in an intact eversion endarterectomy specimen. Methods: Preoperative angiograms (intraarterial DSA, 512 x 512 matrix) and CT-angiograms (24 sec spiral scan, slice thickness 2 mm, pitch 1.5) were taken in 12 patients with symptomatic carotid stenosis. Evaluation of the degree of stenosis was performed according to the NASCET (''distal'' degree) and ECST (''local'' degree) methods. These data were compared with measurements of the surgical specimens. Results. The median ''local'' degree of stenosis in angiograms was 81.5% (range: 70-99%), in CT angiograms 83% (59-94%) and in specimens 85.5% (65-96%). The ''distal'' degree of stenosis was 79% (50-99%) in angiograms, 85.5% (55-99%) in CT angiograms and 81% (52-95%) in specimens. CT angiography slightly overestimated the degree of stenosis compared with the specimen, whereas angiography slightly underestimated the true degree of stenosis. However, these differences were not statistically significant. Conclusion: CT angiography is able to predict the degree of internal carotid stenosis when compared with an intact surgical specimen. It is as accurate as the ''gold standard'' of invasive angiography.