缺血性脑血管病是人类常见病、多发病，不仅发病率高，而且致残率、死亡率均高，在各类脑血管病中，缺血性脑血管病占60％～70％，研究发现颈动脉顾外段病变在缺血性脑血管病发病机理中起重要作用。颈动脉多普勒超声检查可检出动脉内膜增厚、粥样硬化斑块、血管腔的狭窄、血流 Ischemic cerebrovascular disease is a common human disease, frequently-occurring disease, not only the high incidence of morbidity and mortality are high, in all types of cerebrovascular disease, ischemic cerebrovascular disease accounted for 60% to 70% Study found that external carotid artery lesions in the pathogenesis of ischemic cerebrovascular disease plays an important role. Carotid artery Doppler ultrasound can detect arterial intimal thickening, atherosclerotic plaque, narrowing of the lumen, blood flow