Quantitative Study On The Characteristics Of Responsibility Plaque In Acute Ischemic Stroke Under Different Stenosis Rates Based On MR-VWI

Objective: MR-VWI technique was used to quantitatively study the difference of MCA responsible plaques between<50% and≥50%M1 segments of primary acute ischemic stroke,and what are the characteristics of MCA responsible plaques in M1 segment of primary acute ischemic stroke excluding luminal stenosis factors.Methods: A retrospective study was conducted on 72 patients who underwent MR-VWI examination from January 2018 to December 2020 because of initial ischemic stroke.The responsible vessel was identified as M1 segment MCA according to DWI,TOF-MRA and pre-and post-enhanced MR-VWI images.According to the onset time,the patients were divided into acute ischemic stroke(time≤2 weeks)and non-acute ischemic stroke(time>2 weeks).According to the lumen stenosis rate measured by MR-VWI,the initial acute ischemic stroke was divided into lumen stenosis rate<50%and stenosis rate≥50%.The characteristics of responsible plaques(patch load,reconstruction index,patch length,eccentricity index,enhancement index,enhancement degree)were measured manually.The characteristics of responsible plaque in different lumen stenosis rates of primary acute ischemic stroke and the characteristics of responsible plaque in primary acute group and non-acute group were statistically analyzed.Results: There was no difference in clinical data between the group with stenosis rate<50% and the group with stenosis rate≥50%(p>0.05).Compared with the group with stenosis rate≥50%,the group with stenosis rate<50% had higher remodeling index(p<0.001)and lower plaque load(p<0.001).There was no significant difference in demographic data between initial acute ischemic stroke group and non-acute ischemic stroke group(p>0.05).Excluding the factors of lumen stenosis,the plaque enhancement index(p<0.001)and plaque load(p<0.001)in the first acute ischemic stroke group were higher than those in the non-acute ischemic stroke group.Conclusion:The first acute ischemic stroke with lumen stenosis rate<50% showed more positive remodeling and less plaque load in M1 segment,and more negative remodeling and greater plaque load were found in M1 segment of acute ischemic stroke with stenosis rate≥50%.Excluding the factors of lumen stenosis,the plaque load and enhancement index of responsibility plaque on M1 segment MCA of primary acute ischemic stroke were higher than those of non-acute ischemic stroke.