High-resolution Real-time Sonography in the Evaluation of Carotid Atherosclerosis

Abstract

High-resolution real-time sonography (HRS) is usually performed in patients with occlusive cerebrovascular disease. Unfortunately, there is no standard imaging technique for carotid imaging. In this report, an imaging technique for detecting carotid plaques is introduced. At first, to get the most suitable image of the carotid bifurcation in the longitudinal projection, examination was carried out with a 7.5 MHz probe. The probe should maintain constant movement with the same slow speed to detect details of the plaque. The ultrasonic images were recorded with a video tape recorder simultaneously. After that, the most suitable multiple consecutive planes (5 to 7 planes) were re-photographed. Postoperatively, the detailed ultrasonographic images were reviewed and compared with the patho-morphological findings of the planes. A 57-year-old patient with an episode of amaurosis fugax was reported. He had ulcerated and calcified plaques in the left cervical carotid artery. The postoperative macro- and microscopic findings showed good correlations to the display of images at the preoperative ultrasonic examinations. The echo-density of all atheromatous plaques except for those accompanied by calcification, was lower than that of the normal media. It was very difficult to distinguish a true ulceration from a necrosis (or a bleeding space) in the arterial wall. In this case the detailed and consecutive display of the high-resolution B-mode scan was a very useful method to identify a fine structure of atheromatous plaques of the arterial wall in the cervical carotid artery.