MCAO脑缺血后同侧黑质MRI动态改变  

MRI dynamic changes in the ipsilateral substantia nigra following MCAO cerebral ischemia

作　　者：杨艳梅[1] 冯晓源[1] 姚振威[1] 蒋胜洪[1] 刘含秋[1] 张放[1] 童彤[1] 王非[1] 

机构地区：[1]复旦大学华山医院放射科,上海200040

出　　处：《中国临床医学影像杂志》2007年第2期77-80,共4页Journal of China Clinic Medical Imaging

摘　　要：目的:分析线栓法制作单侧大脑中动脉供血区脑缺血后同侧黑质的MR信号变化特点。方法:清洁级健康雄性SD大鼠(270～320g)16只,按照随机分组原则分成两组:永久性大脑中动脉阻塞(MCAO)组12只,假手术对照组4只。应用线栓法制作脑缺血模型,模型制作成功后1h、3h、6h、9h、12h、1d、3d、7d行俯卧位冠状面磁共振扫描。主要序列包括T2WI、T2map,观察脑缺血范围,计算并测量两侧纹状体、皮质和黑质T2值。结果:假手术对照组磁共振图像上双侧纹状体、皮质及黑质等脑组织各部均未出现异常表现。MCAO组大鼠MR扫描显示脑缺血范围累及脑皮质和左侧纹状体及其它皮质下结构,脑缺血区T2信号的动态变化具有一定的时间特征。1h、3h、6h、9h、12h、1d时双侧黑质未见异常MR表现。3d时MCAO组动物均显示脑缺血同侧黑质T2高信号,境界清楚,由T2map测得T2值增高。对侧黑质信号无明显变化,两侧黑质T2值差异有显著意义。7dMCAO组大鼠左侧黑质异常信号消失,双侧黑质T2值未见差异。MCAO后同侧黑质T2值的变化曲线与脑皮质和纹状体T2值的变化不同步。结论:线栓法制作单侧大脑中动脉阻塞脑缺血后3d同侧黑质出现MR异常信号。Objective： To analyze the MRI features of the substantia nigra（SN） following single side middle cerebral artery （MCA） occlusion by intraluminal thread in rats. Materials and Methods： Healthy adult male Sprague-Dawley rats （n=16） weighting 270 to 320g were divided into two groups randomly： permanent MCA occlusion （MCAO） group included 12 rats, and 4 rats in control group was sham-operated. The T2WI and absolute T2 values of the SN, cortex and striatum on MRI were assessed on 1h, 3h, 6h, 9h, 12h, 1d, 3d and 7d after MCAO using a 3.0T MR scanner. Results： The brains of the animals in the control group showed no noteworthy abnormality on MRI. All the rats in MCAO group showed cerebral infarction involving the ipsilateral cortex and striatum. The T2WI signal intensity of the mentioned lesions in MCAO group showed a dynamic changes according to time. No changes of bilateral SN can be seen on 1h, 3h, 6h, 9h, 12h and 1d after MCAO. On the 3rd day, the SN of the ipsilateral side to the occluded MCA showed obviously higher signal intensity on T2WI than that of the contralateral side with a clear demarcation. No changes of the signal on the contralateral side could be observed. The difference of the T2 value between the bilateral SN was significant. These changes in the ipsilateral SN were not displayed on the 7th day. The trend of the T2 value change of ipsilateral SN was not in-phase with that of cortex and striatum. Conclusios： MR signal changes can be seen in the ipsilateral SN on the 3rd day after MCAO.

关 键 词：脑缺血 黑质 磁共振成像 

分 类 号：R743.31[医药卫生—神经病学与精神病学] R445.2[医药卫生—临床医学]