3.0T-HRMRI Study In The Diagnosis And Prognostic Evaluation Of Symptomatic Middle Cerebral Atherosclerotic

Objective: High resolution magnetic resonance imaging(HRMRI)technique was used to classify middle cerebral artery(MCA)atherosclerotic plaques and compare the plaque features of symptomatic and asymptomatic MCA atherosclerotic,in order to evaluate the clinical significance of 3.0T-HRMRI in the recovery and predicting outcome of patients with MCA atherosclerotic ischemic stroke(IS).Methods: We collected 63 patients with MCA atherosclerosis IS and completed the3.0T-HRMRI examination within 7 days after the onset,and 49 asymptomatic MCA atherosclerosis patients as controls for 3.0T-HRMRI examination,to compare the MCA atherosclerosis between the two groups plaque characteristics.In addition,we followed up 6months later to analyze the plaque characteristics of recurrent/new stroke patients.We performed the National Institutes of International Health Stroke Scale(NIHSS)scores on patients in the symptom group on the 1,7 and 14 days of admission,and the modified RANKIN(MRS)score on the 90 th day of admission to compare the severity and prognosis of different types of plaques in the symptom group.Results: 3.0T-HRMRI was performed in both groups,and the results were as follows1.Symptomatic vs.asymptomatic plaque characteristics(1)The number of enhanced plaques(71.4% vs 42.9%),plaque load(0.71±0.10 vs 0.62±0.15),plaque area at the stenosis site(5.19±0.91 vs 4.03±1.26),vascular area at the stenosis site(15.53±1.19 vs 14.96±1.32)and vascular remodeling index(1.06±0.12 vs 0.97±0.09)in the symptomatic group were higher than those in the asymptomatic group P<0.05.(2)The rate of vascular stenosis(64.87±12.24 vs 53.33±12.53)and the area of the most narrow lumen(4.81±1.17 vs 5.35±1.40)were lower in the symptomatic group than in the asymptomatic group,P<0.05;(3)In terms of vascular remodeling,the number of positive remodeling in the symptomatic group was higher than that in the asymptomatic group(54.0% vs 16.3%),while the number of negative remodeling was lower than that in the asymptomatic group(25.4% vs 46.9%),P<0.05.There was no significant difference in the number of intermediate remodeling between the two groups(20.6% vs 36.7%),P>0.05.(4)There was no significant difference between the two groups in the location of the ventral(28.6% vs 32.7%),dorsal(23.8% vs 16.3%),lower wall(14.2% vs 28.6%)and upper wall(33.3% vs 22.4%),P>0.05.2.Plaque characteristics in recurrence/new IS vs.no recurrence Follow-up 6 months later,10 patients had recurrence/new IS,including 7 in symptomatic group and 3 in asymptomatic group,compared the recurrence/new patients with no recurrence of the new patch characteristics,we found that the former is more than the latter in plaque load(0.75 ± 0.06 vs.0.67 ± 0.08),luminal stenosis rate(74.13±11.85 vs.58.56 ± 10.46)and the narrowest place plaque area(5.40 ± 0.76 vs 4.73 ± 0.49),P < 0.05;The area of the narrowest lumen in the relapsed/newly diagnosed group(4.54±0.80 vs 5.20±0.62)was smaller than that in the non-relapsed/newly diagnosed group(P<0.05).There were no significant differences between the two groups in enhanced plaques(90.0% vs 58.8%),eccentric plaques(60.0% vs 52.9%),remodeling index(0.97±0.11 vs 0.95±0.08)and vascular area at the strictest site(15.54±0.77 vs 15.07±0.64),P>0.05.3.Plaque typing in symptomatic vs asymptomatic groups Symptom group vs asymptomatic group:type I-II 0 vs 2.0%,P>0.05;type III 9.5% vs34.7%,P<0.05;IV-V plaque 33.3% vs 26.5%,P>0.05;Type VI plaque 44.4% vs 8.2%,P<0.05;7.9% vs 14.3% in type VII plaque,P>0.05;Type VIII plaque was 4.8% vs 20.4%(P<0.05).4.Relationship between plaque typing and NIHSS scores Among the 63 patients in the symptomatic group,we were found 0 cases of I-II type plaque,6 cases of III type plaque,21 cases of IV-V type plaque,28 cases of VI type plaque,5cases of VII type and 3 cases of VIII type plaques.Among them,III type,VII type and VIII type plaques are stable plaques,and IV-V type and VI plaques are unstable plaques.The results showed that:(1)NIHSS scores of patients with unstable plaques and stable plaques at different time points:There was no significant difference between IV-V type(7.85±2.66),VI type(8.04±2.76)and stable type(6.93±2.50)on day 1,P>0.05;on day 7,stable plaque(2.40±2.79))Is smaller than IV-V(6.00±3.63)and VI type plaques(5.39±3.51),P<0.05;stable plaques(0.80±1.30)on the14 th day are smaller than IV-V(3.81±3.16)and VI type(3.25±2.95)plaque,P<0.05;(2)Changes in NIHSS score difference within 14 days: between day 7 and day 1,patients with IV-V type plaque was 2.24±0.18,the VI type plaue was 2.07±0.17,and 2.00±0.15 for stable plaque,P>0.05;NIHSS score changes of IV type plaques(3.76±0.62)and stable plaques(2.45±1.00)on day 14 and day 1 were less than those of VI type plaques(4.83±0.83),P<0.05;5.Relationship between plaque typing and MRS scores The MRS scores of patients with unstable(IV-V,VI)and stable plaques on day 90,P>0.05.Conclusion:1.3.0T-HRMRI can effectively evaluate the features of MCA atherosclerotic plaques and be used for image classification of MCA atherosclerotic plaques;2.The characteristics of different types of plaques differentiated by 3.0T-HRMRI were used to evaluate the severity and prognosis of the disease,and assist clinicians in evaluating the therapeutic effect;3.3.0T-HRMRI may be able to predict the occurrence of acute ischemic stroke by evaluating atherosclerotic plaques in MCA.