急性脑梗死腔内再通后液体衰减反转恢复序列高信号血管征变化的意义

Significance of change of fluid-attenuated inversion recovery hyperintense vessel sign after endovascular recanalization in acute ischemic stroke

目的探讨急性脑梗死腔内再通后MR液体衰减反转恢复序列（fluid．attenuated inversion recovery，FLAIR）高信号血管征（hyperintense vessel sign，HVS）的变化及其意义。方法回顾性分析2013年1月至2014年10月间经Solitaire支架取栓治疗的急性大脑中动脉闭塞患者的影像及临床资料。患者纳入标准：（1）术前MR检查资料完整，包括常规平扫的FLAIR、DWI、MRA及灌注加权成像（perfusion—weighted imaging，PWI），且FLAIR序列存在HVS；（2）血管内治疗术中脑血管造影证实大脑中动脉M1段闭塞；（3）术后48h内接受与术前相同序列的MR检查。符合以上纳入标准的患者共11例。按照脑梗死溶栓等级系统（thrombolysis in cerebral infarction，TICI）评价大脑中动脉再通情况，并分析其与血管再通后HVS变化及DWI变化的关系。结果11例急性大脑中动脉闭塞患者血管内治疗术后MRI复查9例HVS完全消失，大脑中动脉再通为TICI3级，DWI高信号区较术前略缩小1例、轻度增大6例、明显增大2例。2例表现为HVS部分消失且残留HVS信号强度较术前降低，其中1例大脑中动脉再通为TICI2a级（再通不足）、1例为TICI2b级（充分再通），但大脑中动脉M1段残余重度狭窄，此2例患者DWI高信号区较术均明显增大。结论急性脑梗死血管成功再通后FLAIR序列HVS消失或信号强度减弱可作为脑血流灌注改善的标志。

Objective To investigate the significance of change of fluid-attenuated inversion recovery（FLAIR） hyperintense vessel sign（HVS） after endovascular recanalization in acute ischemic stroke. Methods The clinical and imaging data of the patients with acute middle cerebral artery（MCA） occlusion treated by mechanical thrombectomy with Solitaire AB from January 2013 to october 2014 were analyzed retrospectively. The inclusion criteria： （1） The preoperative MRI included conventional non-enhanced MR, diffusion-weighted imaging （DWI）, magnetic resonance angiography（MRA） and perfusion-weighted imaging （PWI）, and HVS was observed on preoperative FLAIR images; （2） acute MCA occlusion verified by conventional angiography; （3） postoperative similar MR images examination was performed within 48 hours. The relationships among postoperative changes in the HVS, DWI and Thrombolysis In Cerebral Ischemia （TICI） scale （1--3） were assessed. Results After endovascular therapy, HVS of the 11 cases were showed to be disappeared（n = 9） and decreased （n = 2）. All the 9 patients with disappeared HVS achieved high grade flow （TICI 3）, and minor decrease of ischemic area on DWI in 1 case, minor progression in 6, and significant progression in 2. However, of the 2 patients with decreased HVS, one achieved relatively low grade flow （TICI 2a） and the other was found to be relatively high grade flow （TICI 2b）, but severe MCA stenosis. DWI demonstrated significant progression in both two cases. Conclusion Our data indicate that endovascular recanalization of acute MCA occlusion was effective for decreasing HVS. Postoperative decrease and disappear in HVS can be considered as a marker for hemodynamic improvement.