前循环梗死患者影像学梗死模式和发病机制初探

目的 从磁共振弥散加权成像(diffusion-weighted imaging,DWI)角度,分析颈内动脉(internal carotid artery,ICA)、大脑中动脉(middle cerebral artery,MCA)重度狭窄或闭塞患者脑梗死的影像学模式特点,探讨其相应的梗死机制.方法 回顾性分析88例经全脑血管造影证实存在ICA、MCA中重度狭窄或闭塞的急性缺血性梗死患者,将其分为ICA病变组和MCA病变组.根据DWI将梗死模式分为单发和多发,前者再分为穿支动脉梗死(perforating artery infarct,PAI)、皮质支梗死(pial infarct,PI)、分水岭梗死和大面积梗死.结果 MCA供血区梗死模式可分为11种.DWI多发梗死模式占所有患者的62.5%(55/88).ICA病变组更多出现PI伴发分水岭梗死(11/45,P=0.040),而MCA病变组更多出现PI伴发PAI(10/43,P=0.037).结论 在伴有ICA或MCA重度狭窄或闭塞的脑梗死患者中,大多数表现为多发梗死模式,提示栓塞、低灌注/栓子清除能力下降以及局部穿支闭塞等机制是其发生梗死的主要机制.ICA病变组梗死的主要机制为栓塞合并低灌注/栓子清除能力下降,而MCA病变组则为栓塞合并局部穿支闭塞.

Preliminary study of imaging infarct patterns and pathogenesis in patients with anterior circulation infarction

Objective To analyze imaging infarct patterns and features in patients with severe stenosis or occlusion of internal carotid artery (ICA) and middle cerebral artery (MCA)from the point of view of diffusion-weighted imaging (DWI) and to investigate the infarction related mechanism. Methods Eighty-eight patients with acute ischemic stroke who had moderate to severe ICA or MCA stenosis or occlusion confirmed by cerebral angiography were analyzed retrospectively. They were divided into ICA lesion and MCA lesion groups. The infarct patterns were classified as single and multiple according to DWI. The former were reclassified as perforating artery infarct (PAI), pial infarct (PI), watershed infarct, and large infarct. Results There were 11 types of infarct patterns in MCA territories. The DWI multi-infarct pattern accounted for 62.5% of all patients (55/88). PI with watershed infarction appeared more often in the ICA lesion group (11/45, P=0. 040), and PI with PAI appeared more often in the MCA lesion group (10/43, P = 0. 037). Conclusions In patients with cerebral infarction associated with ICA or MCA severe stenosis or occlusion, most of them showed multi-infarct pattern,which suggested the mixed mechanisms such as embolization, hypoperfusion/impaired clearance of emboli, and local perforating branch occlusion were the main mechanisms of the occurrence of cerebral infarction. The main mechanism of cerebral infarction in the ICA lesion group was embolization combined with hypoperfusion/impaired clearance of emboli, while in the MCA lesion group was embolization combined with local perforating branch occlusion.