BACKGROUND AND PURPOSE Various mechanisms are involved in the etiology of stroke caused by atherosclerosis of the middle cerebral artery (MCA). Here, we compared differences in plaque nature and hemodynamic parameters according to stroke mechanism in patients with MCA atherosclerosis. METHODS Consecutive patients with asymptomatic and symptomatic MCA atherosclerosis (≥50% stenosis) were enrolled. MCA plaque characteristics (location and plaque enhancement) and wall shear stress (WSS) were measured using high-resolution vessel wall and four-dimensional flow magnetic resonance imaging, respectively, at five points (initial, upstream, minimal lumen, downstream, and terminal). These parameters were compared between patients with asymptomatic and symptomatic MCA atherosclerosis with infarctions of different mechanisms (artery-to-artery embolism vs. local branch occlusion). RESULTS In total, 110 patients (46 asymptomatic, 32 artery-to-artery embolisms, and 32 local branch occlusions) were investigated. Plaques were evenly distributed in the MCA of patients with asymptomatic MCA atherosclerosis, more commonly observed in the distal MCA of patients with artery-to-artery embolism, and in the middle MCA of patients with local branch occlusion. Maximum WSS and plaque enhancement were more prominent in the minimum lumen area of patients with asymptomatic MCA atherosclerosis or those with local branch occlusion, and were more prominent in the upstream area in those with artery-to-artery embolism. The elevated variability in the maximum WSS was related to stroke caused by artery-to-artery embolism. CONCLUSION Stroke caused by artery-to-artery embolism was related to plaque enhancement and the highest maximum WSS at the upstream point of the plaque, and was associated with elevated variability of maximum WSS.

中文翻译：

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与中风发生和大脑中动脉粥样硬化机制相关的壁面剪切应力。

背景和目的 大脑中动脉 (MCA) 动脉粥样硬化引起的卒中的病因学涉及多种机制。在这里，我们根据 MCA 动脉粥样硬化患者的卒中机制比较了斑块性质和血液动力学参数的差异。方法连续纳入无症状和有症状的 MCA 动脉粥样硬化（≥50% 狭窄）患者。使用高分辨率血管壁和四维流动磁共振成像分别在五个点（初始、上游、最小管腔、下游和末端）测量 MCA 斑块特征（位置和斑块增强）和壁剪切应力 (WSS) ). 这些参数在无症状和有症状的 MCA 动脉粥样硬化患者之间进行了比较，这些患者具有不同机制的梗塞（动脉到动脉栓塞与动脉栓塞）。局部分支阻塞）。结果 总共对 110 名患者（46 名无症状、32 名动脉间栓塞和 32 名局部分支闭塞）进行了调查。斑块均匀分布于无症状 MCA 动脉粥样硬化患者的 MCA，更常见于动脉间栓塞患者的远端 MCA 和局部分支闭塞患者的 MCA 中部。最大WSS和斑块增强在无症状MCA动脉粥样硬化或局部分支闭塞患者的最小管腔区域更为突出，在动脉-动脉栓塞患者的上游区域更为突出。最大 WSS 的变异性升高与动脉到动脉栓塞引起的中风有关。