大脑中动脉形态与斑块分布及卒中的HR-MRI研究

HR-MRI Study of Morphology and Plaque Distribution of Middle Cerebral Artery and Stroke

目的分析大脑中动脉(MCA)几何特征与动脉粥样硬化斑块分布和卒中的关系。方法纳入症状性MCA斑块患者,根据有无梗死分为两组;并进一步根据斑块是否累及内侧壁分组,利用三维磁共振血管成像(3D-MRA)及重组最大密度投影(MIP)识别MCA曲线类型及方向,于高分辨率磁共振成像(HR-MRI)上确定斑块分布及其他斑块特征(斑块负荷、斑块长度及强化程度等),分析症状性MCA动脉粥样硬化患者MCA几何特征、斑块分布与卒中的关系。结果最终纳入46例患者,其中MCA M1段弯曲占91.3%;与20例MCA无梗死组患者相比,26例MCA梗死组患者有较低的下向曲线(P=0.013),较多的上侧斑块(P=0.031)、较大的斑块面积(P=0.045)、较大的狭窄程度(P=0.02)和更高比例的斑块强化(P=0.001);累及MCA曲线内侧壁的斑块更长(P=0.016);上侧斑块的存在与卒中独立相关(OR=9.24,95%CI 1.04~82.27)。结论MCA上向M1曲线可能为上侧斑块的形成和进展创造不利环境,提示血管几何学可能至少在一定程度上通过影响斑块的位置而促进缺血性梗死的发生。

Objective To analyze the relationship between the geometric characteristics of MCA and the distribution of atherosclerotic plaque and stroke.Methods Patients with symptomatic MCA plaques were retrospectively enrolled and divided into two groups according to the presence or absence of infarction;and further grouped according to whether the plaques involved the medial wall.We used 3 D-MRA and reconstructed MIP were used to identify the type and direction of the MCA curve,and HR-MRI to determine plaque distribution and other plaque characteristics(plaque load,plaque length and degree of enhancement,etc.),and analyze the relationship between MCA geometric characteristics,plaque distribution and stroke in patients with symptomatic MCA atherosclerosis.Results 46 patients were finally enrolled,of which the middle cerebral artery M1 segment accounted for 91.3%;compared with 20 patients in the MCA non-infarct group,26 patients in the MCA infarction group had a lower downward curve(P=0.013),and more Upward plaque(P=0.031),larger plaque area(P=0.045),greater degree of stenosis(P=0.02),and higher proportion of plaque enhancement(P=0.001).When the MCA curve was involved,the plaque on the medial wall was longer(P=0.016).The presence of the upper plaque was independently associated with stroke(OR=9.24,95%CI 1.04–82.27).Conclusion The upward M1 curve of the middle cerebral artery may create an unfavorable environment for the formation and progression of upward plaque,suggesting that vascular geometry may at least to some extent affect the position of the plaque and promote the occurrence of ischemic infarction.