This report describes a newly developed noninvasive method for extracranial cerebrovascular evaluation. Two hundred consecutive cases were studied at the Massachusetts General Hospital and matched with clinical and angiographic findings. There were three false negative and five false positive results. Two ulcerated plaques without stenosis were not detected. Management routes for different groups of patients with central nervous system symptoms are outlined. We emphasize the usefulness of monitoring postoperative ophthalmic artery pressure to aid in the early detection of carotid occlusion in patients developing neurologic symptoms following carotid endarterectomy.