椎基底动脉延长扩张症的FLAIR影像分析

Analysis of imaging manifestations on fluid-attenuated inversion recovery sequence in vertebribasilar dolichoectasia

目的:探讨在椎基底动脉延长扩张症(VBD)患者FLAIR序列中血管高信号征(FVH)的特征及其意义。方法:2011年1月-2015年4月本院确诊的49例VBD患者,所有患者均行MRI常规检查及TOF-MRA检查,按照临床表现分为后循环缺血组(18例)及非后循环缺血组(31例),比较两组临床资料及影像表现的差异,并分析FVH征的临床意义。结果:49例VBD患者中,36例(73.5%)血管FVH征阳性。其中,22例(44.9%)表现为1级,11例表现为2级(22.4%),3例(6.1%)表现为3级,后循环缺血组FVH评分较高者(2或3级)的构成比显著高于非后循环缺血组(55.6%vs 12.9%,χ2=11.493,P=0.009)。VBD患者的FVH分级与基底动脉(BA)直径、长度及BA横向偏移之间具有低度相关性(r=0.473,P=0.001;r=0.483,P<0.001;r=0.542,P<0.001)。结论:VBD患者FVH征阳性率高,其形成机制可能与BA血流缓慢有关,且高级别FVH(2或3级)的出现可以提示VBD患者发生后循环缺血的可能性较大。

Objective：To study the features and significance of hypertense vessel sign（HVS）on FLAIR MRI in patients with vertebrobasilar artery dolichoectasia（VBD）.Methods：Forty-nine patients with VBD admitted in our hospital from January 2011 to April 2015 were included in this study.All patients completed routine MRI and TOF-MRA examination.According to the clinical manifestations of post circulation ischemia（PCI）,all patients were classified into positive PCI（18cases）and negative PCI groups（31cases）.The clinical materials and imaging features of the two groups were compared,and the clinical significance of HVS on FLAIR sequence was analyzed.Results：Of the 49 cases with VBD,36patients（73.5%）were positive for HVS on FLAIR sequence.Among them,there were 22patients（44.9%）as grade 1,11 as grade2（22.4%）,3as grade 3（6.1%）.The constitute ratio of higher FVH score（2or 3）in positive PCI group was significantly higher than that of negative PCI group（55.6% vs 12.9%,χ2=11.493,P=0.009）.The diameter、length and lateral displacement of the basilar artery had low correlation with the grading of HVS on FLAIR sequence（r=0.473,P=0.001;r=0.483,P0.001;r=0.542,P〈0.001）.Conclusion：The positive rate of HVS on FLAIR sequence in VBD patients was high.HVS on FLAIR sequence most likely correlate with slow arterial blood flow in VBD,and a higher grade of HVS on FLAIR sequence（grade 2or 3）might suggest the possibility of VBD patients having posterior circulation ischemia.