Study On The Relationship Between Symptomatic Middle Cerebral Artery Atherosclerotic Plaque And Infarction Patterns By High-resolution Magnetic Resonance Vessel Wall Imaging

Objective To study the symptomatic middle cerebral artery(MCA)atherosclerotic plaque by high-resolution magnetic resonance vessel wall imaging(VW-MRI),investigate the relationship between plaque characteristics and infarction patterns,and speculate on possible stroke mechanisms.Methods Patients with MCA atherosclerotic acute ischemic stroke in Zhongda Hospital Affiliated to Southeast University from December 2017 to February 2019 were collected.Clinical data of all patients were collected,conventional head magnetic resonance imaging(MRI)and cervicocerebral 3.0T VW-MRI were performed for all patients.Patients were divided into embolic infarction group and perforating infarction group based on diffusion weighted imaging(DWI)findings.Imaging indexes such as plaque burden,stenosis rate,remodeling index and plaque enhancement were measured,plaque distribution,high signal on T1-weighted images(HST1)and plaque surface irregularity were analyzed on T1 weighted imaging-volume isotropic turbo spin echo acquisition(T1-VISTA)(before and after contrast).The clinical and imaging data of the embolic infarction group and the perforating infarction group were compared.Results 43 patients were analyzed,including 23 patients in embolic infarction group and 20 patients in perforating infarction group.HST1 were more frequently observed in embolic infarction group(60.9% vs 20.0%,P=0.007).10 of the 16 HST1(62.5%)demonstrated hyperintense spots or areas located adjacent to the lumen versus 6 HST1(37.5%)located within the plaque in embolic infarction group.Furthermore,a higher incidence of plaque surface irregularity was also observed in embolic infarction group(43.5% vs 15.0%,P=0.043).The distribution of plaque enhancement was statistically different between the two groups(P=0.039),there was more grade 2 enhancement(60.9%)in embolic infarction group,however,the perforating infarction group had more grade 1 enhancement(55.0%).Logistic regression analysis showed that HST1 was the independent predictor of embolic infarction group(P=0.025,OR 0.139,95%CI 0.025~0.777).Conclusions Compared with perforating infarction group,embolic infarction group has distinct vulnerable plaque characteristic,including HST1 and plaque surface irregularity,of which HST1 may predict embolic infarction.The distribution of plaque enhancement is also different between the two groups.VW-MRI can clearly show intracranial atherosclerotic plaque,evaluate plaque characteristics,and provide clues to determinate the infarction patterns and stroke mechanisms.