颈内动脉颅外段起始部是动脉粥样硬化斑块的好发部位,斑块常引起管腔严重狭窄或闭塞,它是发生缺血性脑血管病的重要原因之一[1]。颈动脉彩超检查(CDFI)可以直观地发现一侧颈内动脉严重狭窄或闭塞的部位及程度,而经颅多普勒(TCD)可以提供该病变所引起的脑血流动力学改变,二者联合应用,对于全面评估一侧颈内动脉严重狭窄或 The beginning of the extracranial segment of the internal carotid artery is a predilection site of atherosclerotic plaque. Plaque often leads to severe stenosis or occlusion of the lumen. It is one of the important causes of ischemic cerebrovascular disease [1]. Carotid ultrasonography (CDFI) can be intuitively found on one side of the internal carotid artery severe stenosis or occlusion of the site and extent, and transcranial Doppler (TCD) can provide the disease caused by cerebral hemodynamic changes, both Joint application, for a comprehensive assessment of severe carotid artery stenosis or