高分辨率MRI在大脑中动脉粥样硬化斑块药物治疗随访中的应用

目的 探讨3.0 T高分辨率磁共振(HR-MRI)在大脑中动脉(MCA)斑块所致缺血性脑卒中急性期及非急性期药物治疗随访中的应用价值。方法 前瞻性纳入海军军医大学附属长海医院神经内科及脑外科2012年10月至2015年10月,因MCA粥样硬化狭窄致缺血性脑卒中住院并行HR-MRI管壁成像检查患者,根据患者最近一次症状到HR-MRI检查时间将患者分为急性卒中组与非急性卒中组,所有患者均知情同意接受抗血小板药物及强化降脂治疗,并进行HR-MRI随访复查。HR-MRI扫描序列包括T2WI、T1WI、增强T1WI,同时行常规头颅T2WI、DWI扫描,将治疗前后的HR-MRI图像数据进行对比分析,采用配对样本t检验比较各组责任血管管腔狭窄率、斑块强化率、斑块体积及斑块负荷变化差异及患者美国国立卫生研究院卒中量表(NIHSS)评分、血生化指标变化差异;采用χ2检验对比急性卒中组及非急性卒中组患者脑缺血事件复发差异。结果 本研究共纳入31例责任血管为MCA的急性卒中患者,20例非急性卒中患者。急性卒中组平均随访时间(671.71± 522.86)d,药物治疗后管腔狭窄率(P=0.039)、斑块强化率(P<0.001)、斑块体积(P=0.024)、斑块负荷(P=0.031)均较基线明显好转,神经系统功能NIHSS评分(P<0.001)较基线明显改善,12例随访后进行血脂检查的患者总胆固醇(TC)(P=0.011)、低密度脂蛋白胆固醇(LDL-C)(P=0.047)较基线明显降低。非急性卒中组患者平均随访时间为(695.35±555.90)d,随访后HR-MRI图像斑块变化:管腔狭窄率、斑块体积、斑块负荷均较基线稍减小,斑块强化率稍减低,但差异无统计学意义(P>0.05),神经系统功能NIHSS评分较基线变化不明显(P>0.05),7例随访后进行血脂检查患者TC、甘油三酯(TG)、LDL-C变化较基线无明显变化(P>0.05),但高密度脂蛋白胆固醇(HDL-C)较基线升高(P=0.02)。随访期间两组患者颅脑DWI图像均未发现复发新鲜脑梗死灶,急性卒中组患者短暂性脑缺血发作(TIA)复发6例,非急性卒中组患者TIA复发5例,两组TIA复发差异无统计学意义(χ2=0.229,P=0.632)。结论 HR-MRI可作为MCA粥样硬化斑块药物治疗随访的重要评估方法,急性期缺血性脑卒中患者经抗血小板及强化降脂治疗后MCA责任斑块体积及斑块负荷减小、斑块强化减低,而非急性期患者斑块治疗后变化不显著。

Evaluate the follow-up effect of drug treatment for middle cerebral artery atherosclerotic plaques using high resolution MRI

Objective To explore the value of 3.0 T high resolution MRI(HR-MRI)in the follow-up of drug treatment in acute and non-acute ischemic stroke caused by middle cerebral artery(MCA)plaque.Methods The perspective study enrolled patients with ischemic stroke caused by MCA stenosis from October 2012 to October 2015 in the department of Neurology and Neurosurgery of Changhai Hospital Affiliated to Naval Medical University.All the patients underwent HR-MRI and then were divided into acute and non-acute stroke groups according to the intervels of the last symptom onset to the time of HR-MRI examination.All patients were informed consent to receive antiplatelet drug and intensive lipid therapy and followed up with HR-MRI.The HR-MRI sequence including T2WI,T1WI and contrast-enhanced T1WI of vessel wall,and T2WI and DWI of brain were routinely performed.T-test of paired samples was used to evaluate the changes of stenosis rate of vascular lumen,plaque enhancement degree,plaque volume and plaque burden on HR-MRI,and the NIHSS score of nervous system and blood biochemical indicators of the patients before and after treatment.Chi square test was used to compare the difference in ischemic event recurrcence between the acute and the non-acute stroke group.Results A total of 31 acute stroke patients and 20 non-acute stroke patients were enrolled in the study.The mean follow-up time of acute stroke group was(671.71±522.86)days.Compare with the baseline,the stenosis rate of vascular lumen(P=0.039),plaque enhancement degree(P<0.001),plaque volume(P=0.024)and plaque burden(P=0.031)were all improved after the drug treatment,the NIHSS score of nervous system was also significantly improved,and the levels of total cholesterol(TC)and low density lipoprotein cholesterol(LDL-C)in 12 patients were significantly decreased.The mean follow-up time of patients with non-acute stroke was(695.35±555.90)days.The stenosis rate of vascular lumen,plaque enhancement degree,plaque volume and plaque burden were slightly improved,but without statistical significance(P>0.05).There were no significant changes in NIHSS score of nervous system,TC,triglyceride(TG)and LDL-C(P>0.05),however the high density lipoprotein cholesterol(HDL-C)was significantly increased than that in the baseline(P=0.02).During the follow-up period,no new cerebral infarction was found in the DWI images of the two groups.Six patients had transient ischemic attack(TIA)recurrence in the acute stroke group and 5 patients in the non-acute stroke group,there was no significant difference between both groups(χ2=0.229,P=0.632).Conclusion HR-MRI can be used as an important evaluation method for the follow-up of MCA atherosclerotic plaque therapy.After antiplatelet therapy and intensive lipid-lowering therapy,the plaque volume and burden of MCA offending plaque,and plaque enhancement decreased in acute stroke patients but there was no significant change in non-acute patients.