The Imaging Studies Of Internal Carotid Artery Atherosclerotic Stenosis And Infarct Patterns

Objective:To analyze the lesion patterns and major stroke mechanism of acute Ischemic stroke in patients with severe internal carotid artery atherosclerotic stenosis or occlusion by using early diffusion-weighted imaging(DWI) combined with CT angiography(CTA) and MR angiography(MRA). Identifying the major contributing mechanism is important to choose an optimal method for acute management and long-term prevention of recurrent stroke and to supply intervention treatment for patients with internal carotid artery atherosclerotic stenosis to prevent acute Ischemic stroke. Subjects and Methods:We recruited 116 patients with acute cerebral infarts who fulfilled the following criteria: 1) lesions of acute infarcts were verified by DWI performed within one week of stroke onset; 2) infarct lesions were located within the territory of unilateral internal carotid artery; 3) infarcts were definitedly caused by severe atherosclerosis stenosis(stenosis rate of 70%-99%) or occlusion of the ipsilateral ACA or MCA or IICA or EICA; 4) all other potential causes of stroke being entirely excluded. According to the location of arteries stenosis, all patients were divided into the ACA group, MCA group, IICA group, EICA group.The topography of ischemic lesions was determined using published templates. The vascular territories were divided into perforator, pial, and borderzone regions. According to the distributions of infarct lesions in the arterial territory of the ICA displayed on DWI, lesion patterns were classified as one of the following 8 patterns: single infarct�(1) perforating artery infarct(PAI);(2) pial infarct(PI);(3) borderzone infarcts(BZI);(4) large territorial infarct; and multiple infarcts �( 5) PI+PAI;(6)PI+BZI;(7)PAI+BZI;(8) PI+PAI+BZI? Results:1.There are 15 patients in ACA group. Eleven patients were male and four patients were female. The most common location of ACA severe stenosis or occlusion is A2 segment(80%). Most patients have single infart(73.3%). Large territorial infarct(40%) is the most common pattern in all patients of ACA group.2. There are 60 patients in MCA group. Thirty-eight patients were male and twenty-two patients were female. The most common location of MCA severe stenosis or occlusion is M1 segment(95%). Most patients have multiple infarts(63.3%). Concomitant pial,and border-zone infarcts(35%) is the most common pattern in all patients of MCA group.3. There are 18 patients in IICA group. Forteen patients were male and four patients were female. The most common location of IICA severe stenosis or occlusion is cavernous segment(66.7%). The number of single infarct and multiple infarcts are equal. In all patients of IICA group, Concomitant BZI and PI and/or PAI is the most common pattern.4. There are 23 patients in EICA group. Eight patients were male and five patients were female. The most common location of EICA severe stenosis or occlusion is a portion of the carotid sinus(60.9%). Most patients have multiple infart(60.9%). Concomitant BZI and PI and/or PAI is the most common pattern. Conclusions:The most commom lesion patterns in patients with severe ACA atherosclerotic stenosis or occlusion is large territorial infarct, which demonstrates situ thrombosis is major mechanism. The most commom lesion patterns in patients with severe MCA atherosclerotic stenosis or occlusion is concomitant pial, and border-zone infarcts, which demonstrates artery-to-artery embolization and hemodynamic compromise is a common stroke mechanism in these patients. Concomitant BZI and PI and/or PAI is the most common pattern in patients with severe IICA or EICA atherosclerotic stenosis or occlusion, which suggests Concomitant artery-to-artery embolization and hemodynamic compromise is a common stroke mechanism.