双标记延迟时间3D-ASL对急性脑梗塞取栓前后脑血流动力学的评估价值

Value of 3D-ASL with Dual Postlabeling Delays in Evaluation Cerebral Hemodynamics Before and After Thrombectomy in Acute Cerebral Infarction

目的探讨磁共振三维动脉自旋标记(3D-ASL)采用双标记延迟时间(PLD)评估急性脑梗死取栓前后脑血流动力学的应用价值。方法搜集行血管内机械取栓的急性脑梗死患者20例,所有患者均于发病6 h内行扩散加权成像(DWI)、磁共振血管成像(MRA)及3D-ASL,ASL采用两个PLD进行扫描。取栓后1~3天复查DWI及ASL,观察取栓前后脑血流灌注情况,计算取栓前梗死侧晚到达逆行血流比例,评估取栓前梗死侧晚到达逆行血流比例与取栓后美国国立卫生研究院卒中量表(NIHSS)评分的相关性。结果20例ASL显示PLD 1.5 s均可见面积大于DWI高信号区的低灌注区,PLD 2.5 s 17例低灌注区缩小,仍可见缺血半暗带,3例低灌注区范围无明显变化。取栓后复查造影显示责任血管灌注达mTICI2b/3级,ASL显示17例低灌注区较取栓前明显缩小,1例范围扩大,2例梗死区域出现片状高灌注区。取栓后大部分患者脑灌注明显改善,取栓前后梗死侧脑血流量(CBF)差异有统计学意义(P<0.05),取栓前梗死侧晚到达逆行血流比例与取栓后NIHSS评分呈负相关。结论双PLD的3D-ASL能更客观地评价取栓前后的脑血流动力学改变,随着标记时间延长,CBF图可以一定程度上评估侧支循环血流储备,为急性脑梗死的预后提供理论依据。

Objective To evaluate the value of three-dimensional arterial spin labeling imaging(3 D ASL)with dual postlabeling delays in evaluating the cerebral hemodynamics before and after thrombectomy in acute cerebral infarction.Methods Acute cerebral infarction patients who received thrombectomy were enrolled in this study.Diffusion weighted imaging(DWI)、MRA and 3 D ASL(with dual labeled delays)were performed within 6 hours after onset of symptoms.All patients were reexamined DWI and 3 D ASL after thrombectomy between 1-3 day.To observe cerebral hemodynamics before and after thrombectomy and calculate late-arriving retrograde flow proportion of infarction area before thrombectomy,and to evaluate the correlation between late-arriving retrograde flow proportion of infarction area and National Institute Health Stroke Scale(NIHSS)after thrombectomy.Results A total of 20 patients who underwent thrombectomy in the Dept.of Cerebral Vascular Intervention of our hospital during July 2017 to September 2018 were enrolled into this study.Asl(PLD1.5 s)showed that The hypoperfusion area was larger than DWI,Asl(PLD2.5 s)showed that 17 cases with smaller hypoperfusion and Ischemic penumbra still exist.DSA showed that the responsible vessel perfusion reached mTICI2 b/3 grade after thrombectomy.Asl showed that 17 cases with Significant smaller hypoperfusion,1 case with larger hypoperfusion and 2 cases with hyperperfusion.There was significant difference between the CBF on infarct side before and after thrombectomy(P<0.05).The late-arriving retrograde flow proportion on the infarct side was negatively correlated with the NIHSS after thrombectomy.Conclusion Asl with dual postlabeling delays can evaluate the cerebral hemodynamic more objectively before and after thrombectomy and evaluate collateral flow,and provide basis for the prognosis of acute cerebral infarction.