Cone-beam CT of the Internal Carotid Artery

摘要

The gold standard for NASCET-type stenosis measurements is currently 2-D digital subtraction angiography (DSA). In this paper, we evaluate the efficacy of 3-D cone-beam, Volumetric Subtraction Angiography (VSA) for assessing internal carotid artery stenosis, by comparison with conventional DSA. VSA perspective maximum intensity projections (MIPs) and DSAs were assessed separately for NASCET-type, minimum stenosis measurements. Although virtually any viewing angle of the VSA was possible, the minimum stenosis grades were not significantly higher than that of the DSAs. Our study of 38 arteries yielded a sensitivity and specificity of 100% (using a clinically relevant 60% stenosis threshold). Measurements from three neuroradiologists provided an average stenosis grade of 75 +- 6 % and 76 +-7 % for the DSA and VSA respectively. A paired student t-test indicated a 98% confidence of no statistical difference in the means. Thus, VSA provides gold standard 3-D information about carotid lumen geometry. While not intended to supplant non-invasive techniques during routine clinical diagnosis, it does provide a 3-D reference standard for research investigations. Additionally, cone-beam CT can provide quantificatation of calcification around the carotid bifurcation.