A New Noninvasive Technique for Imaging Atherosclerotic Plaque in the Aortic Arch of Stroke Patients by Transcutaneous Real-Time B-Mode Ultrasonography

Abstract

BACKGROUND AND PURPOSE: Aortic arch atherosclerotic plaque is a probable source of atheroembolic stroke. Transesophageal echocardiography (TEE) has been used to image the aorta of patients with stroke to identify atherosclerotic plaque. TEE is moderately invasive and does not always visualize plaques present in the distal ascending aorta and proximal aortic arch. METHODS: In the current study, transcutaneous B-mode ultrasonography was performed to image the aortic arch through a lateral supraclavicular window, and the results were compared with those of TEE in 20 patients. The aorta was subdivided into the proximal ascending (PAsc), distal ascending (DAsc), proximal aortic arch (PAA), and distal aortic arch (DAA) to be certain the plaques identified by each technique were the same. Plaques were characterized as simple (<4 mm thick) or complex (>4 mm thick). RESULTS: In the PAsc, 8 simple plaques were identified with TEE but not with B-mode. In the DAsc, 1 complex plaque was identified with both techniques, and B-mode identified 1 additional complex and 1 simple plaque. In the PAA, 6 simple and 5 complex plaques were identified by both techniques, and TEE identified 1 additional complex plaque. In the DAA, TEE identified 2 simple and 2 complex plaques; B-mode identified 3 complex plaques. CONCLUSIONS: B-mode imaging compared favorably with TEE in identification of plaques in the aortic arch and distal ascending aorta, although it could not identify simple plaques in the proximal ascending. B-mode could visualize plaques not seen by TEE in the distal ascending aorta. B-mode ultrasonography is complementary to TEE in performance of a comprehensive assessment of plaque in the aortic arch and provides a noninvasive method for sequential studies of plaques that can be visualized.