B-mode ultrasound imaging in symptomatic internal carotid artery stenosis:Correlation with clinical and operative findings

B-mode ultrasound (duplex) imaging is a technique that enables the evaluati on of plaque characteristics. The purpose of this study was to determine th e accuracy and usefulness of duplex imaging by comparing a relationship bet ween the preoperative clinical neurologic status, preoperative duplex findi ngs, and operative findings in patients who had carotid endarterectomy (CEA ) for symptomatic high-grade internal carotid artery (ICA) stenosis. Sixty patients with symptomatic ICA stenosis who underwent CEA from Septemb er 1995 to August 1998 were included in this study. Plaque morphology was c ategorized in terms of echogenicity by preoperative duplex imaging. A corre lation between the frequency of preoperative ischemic stroke and duplex and operative findings was prospectively evaluated. Thirty-eight patients had recent and multiple cerebral ischemia, and 22 exp erienced a single episode more than 1 month before CEA. Recent and multiple events occurred in 24 (72.7%) of 33 patients with echolucent plaques, but only 6 (40.0%) of 15 with echogenic plaques (p<0.05). Thirty-six (75%) of 4 8 patients with soft plaques by operative findings had recent and multiple events, but only Mo (16.7%) of 12 with calcified plaques experienced recent and multiple events (p<0.01). Overall sensitivity, specificity, and accura cy of duplex imaging were 79.5%, 77.8%, and 79.2%, respectively. Duplex imaging is reliable in determining ICA plaque characteristics. Recen t and multiple cerebral ischemia occurred more frequently in patients with echolucent plaques by preoperative duplex and soft plaques by operative fin dings. The presence of echolucent plaque may be used as a strong indication for CEA in patients who have asymptomatic high-grade ICA stenosis.