B-Mode Flow Imaging of the Carotid Artery

Abstract

Background and Purpose— B-mode ultrasonography has been used to evaluate cervical carotid artery lesions. Recently, the technology for direct visualization of blood reflectors has made B-mode flow imaging (B-flow) possible without the limitations of Doppler technology. We evaluated the efficacy of B-flow in examining the cervical carotid artery. Methods— Sixty patients with ischemic cerebrovascular disease were examined. Conventional B-mode imaging and blood flow images by power Doppler imaging (PDI) and B-flow were obtained. Results— B-flow enabled simultaneous imaging of tissue and blood flow. Compared with PDI, B-flow provided higher spatial resolution and higher frame rate hemodynamic imaging. Consequently, a clear definition of the vessel lumen was obtained even in the stenotic portion of the carotid artery. In evaluating the degree of carotid stenosis, B-flow measurement agreed with digital subtraction angiography as well as PDI measurement. In addition, bloodstream swirl at the site of wall ulceration or vascular elongation was observed. Conclusions— B-flow was prominent in visualizing hemodynamic flow and detection of stenotic lesion in the cervical carotid artery. Combined with conventional B-mode technique, B-flow seems to be useful in evaluating carotid stenosis.