单侧大脑中动脉狭窄程度与磁共振血流灌注相关性研究

目的:探讨大脑中动脉(MCA)狭窄程度与脑磁共振灌注加权成像(PWI)的相关性.方法:30例短暂性脑缺血发作(TIA)患者行高分辨力MRI检查并判断单侧MCA狭窄程度,同时行磁共振PWI检查,并对MCA不同狭窄状态下得出的患侧和镜像侧灌注参数,包括相对脑血容量(rCBV)、相对脑血流量(rBCF)、相对平均通过时间(rMTT)、相对达峰时间(rTTP)进行定量分析.结果:30例患者中,高分辨力MRI均可显示不同程度MCA狭窄,灌注均出现异常,患侧灌注参数rCBV、rCBF、rMTT、rTTP与镜像侧比较,差异均有统计学意义(P＜0.05).MCA狭窄率与rMTT延长百分率之间呈正相关性(r=0.45,P＜0.05).结论:高分辨力MRI对MCA狭窄程度的评估与PWI灌注参数之间存在正相关性,MCA狭窄程度与PWI相结合对于评价脑组织供血有一定的指导意义.

Correlation research between the unilateral MCA stenosis rate and cerebral blood flow MR perfusion-weighted imaging

Objective：To evaluate the correlation between stenosis or occlusion of MCA and the values of the magnetic resonance（MR） perfusion-weighted imaging（PWI）.Methods：MR PWI was performed in 30 TIA patients with unilateral stenosis or occlusion of MCA diagnosed by high-resolution MR.The cerebral perfusion parameters including regional cerebral blood volume（rCBV）,regional cerebral blood flow（rCBF）,regional mean transit time（rMTT） and regional time to peak（rTTP） of both cerebral hemispheres were analyzed.Results：In the 30 patients,unilateral MCA steniosis or occlusion was found by high-resolution MRI and often with abnormal perfusion.The rMTT and rTTP of the involved cerebral hemispheres were significantly increased compared with the contralateral hemispheres in the patients（P0.05）,the rCBV and rCBF were significantly reduced（P0.05）.The rate of the MCA stenosis showed a positive correlation with the extention percentage rMTT（r=0.45,P0.05）.Conclusion：The diagnosis of unilateral MCA stenosis or occlusion by high-resolution MRI showed a positive correlation with PWI,the combination of both can exactly assess the status of blood supply for the cerebral tissues,which is helpful to clinical diagnosis of cerebral ischemia in the patients with unilateral MCA stenosis.