Clinical Study Of Symptomatic Intracranial Atherosclerotic Plaque Based On Three-dimensional High-resolution Magnetic Resonance Imaging

PurposeIntracranial atherosclerosis(ICAS)is the main cause of ischemic stroke and transient ischemic attack(TIA).In recent years,high-resolution magnetic resonance imaging(HR MRI)has been used to investigate the cerebrovascular diseases.The purpose of this study was to evaluate the traditional characteristics and enhancement characteristics of symptomatic intracranial atherosclerotic plaques using 3D HR MRI,as well as the changing trend of plaque features with the course of disease.Meanwhile we want to explore the vulnerability of culprit plaques and the predictive value of ischemic cerebrovascular events recurrence,so as to provide a new potential imaging biomarker for ICAS.MethodsIn this retrospective cohort study,patients with ischemic stroke or TIA attributed to intracranial atherosclerosis who underwent high-resolution magnetic resonance imaging from July 2016 to July 2020 were included.Plaque characteristics,including traditional features and enhancement features were evaluated qualitatively and quantitatively.All plaques were divided into groups according to whether there were ischemic events or not,and the differences between culprit plaques and non-culprit plaques were analyzed.A univariate/multivariate logistic regression analysis was performed to identify the independent variables associated with the culprit plaque.According to the temporal course of ischemic events,the culprit plaques were divided into acute,subacute and chronic stages.The differences of plaque characteristics among the three groups were compared,and the correlation between plaque characteristics and temporal course was analyzed by ordinal logistic regression.Each symptomatic patient was followed clinically for recurrent ischemic events or transient ischemic attack(TIA)up to 72 months or until the recurrence of ischemic cerebrovascular events occurred.Univariate and multivariate Cox regression analyses were used to calculate the association between the plaque characteristics and recurrent events.ResultsPart Ⅰ:231 culprit plaques and 56 non-culprit plaques were detected in 171 patients171 with symptomatic ICAS.In the traditional characteristics,the stenosis ratio,plaque distribution,plaque burden,centripetal thickening,irregular plaque surface and IPH were significantly greater in the culprit plaques than in the nonculprit plaques,and lumen area,remodeling index were lower.In the enhancement characteristics,the enhancement degree,enhancement length,enhancement distribution and the enhancement length/plaque length ratio were significantly greater in the culprit plaques than in the non-culprit plaques.Multivariate regression analysis showed that the stenosis ratio(P<0.001),the degree of enhancement(P=0.002)and enhancement length(P=0.017)were independently associated with the culprit plaque.Part Ⅲ:230 culprit plaques in 170 patients were followed up,with a median follow-up of 16.8 months.There were 39 culprit plaques ocoured recurrent ischemic stroke or TIA.In the recurrent group,stenosis ratio,plaque burden,the degree of enhancement and enhancement length/plaque length ratio were significantly greater and lumen area,remodeling index were lower.Negative remodeling was most common.Multivariate Cox regression analysis suggested that stenosis ratio(P=0.002)and plaque remodeling pattern(P=0.02)were independent risk factors for recurrent cerebrovascular events.Conclusion(1)The degree of enhancement,enhancement length,enhancement distribution and enhancement length/plaque length ratio of culprit plaques were more significant than those of non-culprit plaques.Multidimensional evaluation of the enhancement characteristics of plaques may suggest the pathological mechanism of plaques.(2)The stenosis ratio,degree of enhancement and enhancement length were independently associated with culprit plaque,and plaque enhancement length is a potential imaging marker of culprit plaque.(3)Irregular plaque surface,degree of enhancement,enhancement thickness/plaque thickness ratio and enhancement length/plaque length ratio were associated with the temporal course of ischemic events,reflecting the change of culprit plaque with time.(4)The stenosis ratio and remodeling pattern were independently associated with the recurrence of schemic cerebrovascular events,and the evaluation of plaque characteristics can beter predict the recurrence of stroke and risk stratification.