利用灌注MRI技术评价颈内动脉狭窄或闭塞的血流动力学状态

目的 利用灌注磁共振成像(PWI)技术分析颈内动脉狭窄或闭塞时的血流动力学特点。资料与方法 搜集46例单侧颈内动脉狭窄或闭塞患者的资料，借助PWI对其血流动力学特点进行评价。结果 所有患者局部脑血流量没有显著性降低，但大脑中动脉分布区灌注明显延迟，在重度狭窄及闭塞时，分水岭区的灌注也出现障碍；不同的侧支循环代偿仅对大脑中动脉分布区的灌注有所影响，其中前交通动脉作用较为明显。结论 单侧颈内动脉狭窄时，PWI可以准确评价患者的血流动力学状况，而此时的血流动力学障碍与狭窄程度及侧支循环代偿均有明显的关系。

Perfusion-weighted MRI Evaluation of Hemodynamic Status of Internal Carotid Stenosis or Occlusion

Objective To evaluate hemodynamic characteristics in the stenosis or occlusion of internal carotid artery with perfusion-weighted MRI.Materials and Methods Forty-six patients with unilateral internal carotid stenosis or occlusion were collected. By using perfusion-weighted MRI technique, the hemodynamic status was evaluated.Results In all patients, no significant decrease in regional cerebral blood flow was seen, although marked delayed perfusion in middle cerebral artery distribution could be found. In the patients with severe stenosis or occlusion, perfusion disorder at the border zone was observed. Collateral circulation of different pattern had effect only on the middle cerebral artery distribution area, and the anterior communicating artery showed more obvious effect.Conclusion Perfusion-weighted MRI can precisely evaluate the hemodynamic status in patients with unilateral internal carotid stenosis or occlusion. The hemodynamic disorder is well correlated with both stenotic degree and collateral circulation.