ORIGINAL RESEARCH High-Resolution CT Imaging of Carotid Artery

BACKGROUND AND PURPOSE: Plaque morphologic features have been suggested as a complement to luminal narrowing measurements for assessing the risk of stroke associated with carotid atheroscle-rotic disease, giving rise to the concept of “vulnerable plaque. ” The purpose of this study was to evaluate the ability of multidetector-row CT angiography (CTA) to assess the composition and char-acteristics of carotid artery atherosclerotic plaques with use of histologic examination as the gold standard. MATERIALS ANDMETHODS: Eight patients with transient ischemic attacks who underwent carotid CTA and “en bloc ” endarterectomy were enrolled in a prospective study. An ex vivo micro-CT study of each endarterectomy specimen was obtained, followed by histologic examination. A systematic comparison of CTA images with histologic sections and micro-CT images was performed to determine the CT attenuation associated with each component of the atherosclerotic plaques. A computer algorithm was subsequently developed that automatically identifies the components of the carotid atheroscle-rotic plaques, based on the density of each pixel. A neuroradiologist’s reading of this computer analysis was compared with the interpretation of the histologic slides by a pathologist with respect to the types and characteristics of the carotid plaques