症状性大脑中动脉狭窄斑块分布与缺血性卒中发病机制分型的关系

Relationship Between the Distribution of Plaque in Symptomatic Middle Cerebral Artery Stenosis and Ischemic Stroke Mechanism Subtype

目的探讨症状性大脑中动脉(MCA)狭窄段粥样硬化斑块分布特征及其与缺血性卒中发病机制分型的关系。方法搜集136例粥样硬化性MCA主干M1段狭窄且经磁共振扩散加权成像(DWI)证实同侧MCA供血区急性缺血性脑卒中患者,对MCA狭窄段进行高分辨率磁共振成像(HR MRI)及全脑三维伪连续式动脉自旋标记(3D-p CASL)检查,观察斑块的位置、MCA供血区脑血流量(CBF)及DWI高信号的分布情况,分析斑块分布特征及其引起缺血性卒中的机制是否存在差异。结果 HR MRI清楚地显示MCA狭窄段管壁结构,136例患者中共136支MCA发现斑块,其中前壁斑块36例(26.47%),下壁斑块14例(10.29%),前下壁斑块28例(20.59%),后壁斑块11例(8.08%),上壁斑块10例(7.35%),后上壁斑块9例(6.62%),环形斑块17例(12.5%),前上斑块4例(2.94%),后下斑块7例(5.15%)。前壁、下壁和前下壁斑块引发低灌注/栓子清除下降39(50%)例、动脉到动脉栓塞30(38.46%)例,上壁、后壁和后上壁斑块引发穿支病变21(70%)例,环形斑块引发混合型脑卒中13(76.47%)例,差异有显著性(P<0.001)。低灌注/栓子清除下降缺血性脑卒中症状性MCA供血区CBF值[(30.92±8.75)ml/min/100 g]明显低于镜像侧[(54.17±10.41)ml/min/100 g],差异有显著性(t=14.519,P<0.001)。结论症状性MCA狭窄患者责任动脉粥样硬化斑块的分布与缺血性脑卒中发病机制有关。HR MRI及3D-p CASL技术联合应用有助于揭示缺血性卒中亚型发病机制。

Objective To explore the relationship between the distribution of plaque in symptomatic middle cerebral artery（MCA）stenosis and ischemic stroke mechanism subtypes.MethodsOne hundred and thirty-six acute ischemic stroke patients on diffusion weighted imaging（DWI）with atherosclerotic MCA（M1 segment）stenosis were collected.High resolution magnetic resonance imaging（HR MRI）was performed on the target segment by using a 3.0T MR scanner,and3D-pulsed continuous arterial spin labeling（3D-pC ASL）examination on whole brain was conducted on them.The distribution of plaque and DWI high signal intensity were observed,cerebral blood flow（CBF）in MCA supply area was assessed to compare whether there were differences in cerebral infarction mechanism caused by the distribution of different plaques.Results HR MRI could clearly show the structure of the MCA vascular wall.Among 136 enrolled patients（136 atherosclerotic plaques of MCA）,36（26.47%）patients had ventral plaques,14（10.29%）had inferior wall plaques,28（20.59%）had ventral and inferior wall plaques,11（8.08%）had dorsal plaques,10（7.35%）had superior wall plaques,9（6.62%）had dorsal and superior plaques,17（12.5%）had annular plaques,4（2.94%）had ventral and superior wall plaques,and7（5.15%）had dorsal and inferior wall plaques.Thirty-nine（50%）patients had hypoperfusion/impaired emboli clearance and 30（38.46%）patients had artery-to-artery embolism in the ventral,inferior,ventral and inferior wall plaques,21（70%）had perforating branch lesions in the superior,dorsal,dorsal and superior wall plaques,13（76.47%）had multi-ple mechanisms lesion with annular plaques.Differences were statistically significant（P〈0.001）.The CBF value（30.92±8.75）ml/min/100 g in the affected side MCA supply area were significantly lower than that in（54.17±10.41）ml/min/100 g the contralateral side,t=14.519,P〈0.001）.Conclusion The distribution of plaque in symptomatic MCA stenosis is related to ischemic stroke mechanism subtype.Combining HR MRI with 3D-pC ASL technique may assist in revealing ischemic stroke mechanism subtypes.