症状性颅内动脉硬化性狭窄下游晚期到达逆向血流比率与神经功能缺损的相关性分析

Correlation between late-arriving retrograde flow proportion and neurological deficit in symptomatic intracranial arteriosclerotic stenosis

目的评价单侧大脑中动脉M1段动脉硬化性狭窄下游晚期到达逆向血流与神经功能评分之间的相关性。方法回顾性分析39例伴有症状性单侧大脑中动脉M1段狭窄患者(血管狭窄率为50%~99%)的MRI影像资料,患者均行双标记后延迟时间(post label delay,PLD)(1.5 s和2.5 s)的三维伪连续动脉自旋标记(three-dimensional pseudocontinuous arterial spin labeling,3D pCASL)灌注成像,测量并得到两个PLD的患侧和正常侧的大脑中动脉供血区脑质的平均脑血流量(cerebral blood flow,CBF)值,计算得到患侧大脑中动脉M1段供血区脑质内的晚期到达逆向血流比率(late-arriving retrograde flow proportion,LARFP);记录MRI扫描当日患者的美国国立卫生研究院卒中量表(National Institutes of Health Stroke Scale,NIHSS)评分,测量病变局部血管管腔的狭窄率,采用Pearson相关分析评估LARFP,NIHSS评分及血管狭窄率之间的相关性。结果LARFP与NIHSS评分相关(r=-0.698,P<0.001),而血管狭窄率与LARFP(r=-0.001,P=0.997)、血管狭窄率与NHISS评分(r=-0.127,P=0.440)均不相关。结论LARFP与神经功能缺损有显著的相关性,而血管狭窄率与NIHSS评分之间无显著相关性,由双PLD的3D pCASL成像计算得到的LARFP可能成为今后评价患者脑侧支循环的新指标。

Objective To evaluate the correlation between late-arriving retrograde flow downstream of M1 segmentof unilateral middle cerebral artery(MCA)and neurological function score in patients with arteriosclerotic stenosis.Methods The MRI data of 39 patients with symptomatic M1 stenosis(vascular stenosis rate of 50%-99%)of unilateral MCA were analyzed retrospectively.All patients underwent three-dimensional pseudocontinuous arterial spin labeling(3D pCASL)imaging with dual post-label delay(PLD)(1.5s and 2.5s),the mean cerebral blood flow(CBF)of two PLD downstream of the MCA on the lesion-side and normal-side was measured.The late-arriving retrograde flow proportion(LARFP)downstream of M1 segment of MCA on the lesion-side was calculated.The National Institutes of Health Stroke Scale(NIHSS)scores of patients on the day of the MRI scanning were recorded,and the stenosis ratio of lesioned local vascular lumen was measured.Pearson correlation analysis was used to evaluate the correlation between LARFP,NIHSS score and vascular stenosis ratio.Results There was a correlation between LARFP and NIHSS(r=-0.698;P<0.001),but no correlation between vascular stenosis rate and LARFP(r=-0.001;P=0.997)or NHISS score(r=-0.127;P=0.440).Conclusion LARFP was significantly correlated with neurological deficit,but there was no significant correlation between vascular stenosis ratio and NIHSS score.The LARFP calculated from 3DpCASL imaging using two PLDs may become a new indicator for evaluating cerebral collateral circulation in patients in the future.