目的：通过DTI检测大鼠大脑中动脉闭塞（Middle cerebral artery occlusion，MCAO）后梗死核心远隔区域扩散参数的变化情况，并运用免疫组化检测脑组织RGMa蛋白的表达。检测脑梗死核心区域及双侧小脑半球的扩散情况及病理改变，进一步了解交叉性神经机能联系不能（Crossed cerebellar diaschisis，CCD）的相关机制。方法：将所有动物随机分为2组，实验组56只，对照组14只。实验组及对照组大鼠在模型制作成功后1 h、3 h、6 h、9 h、12 h、24 h和72 h分别行MRI动态观察，并用免疫组化法检测大鼠双侧小脑半球RGMa蛋白的表达。结果：实验组大鼠MCAO后各时间点，磁共振成像结果示：双侧小脑半球与正常对照组相比，FA值均降低，12 h降至最低，对侧（右侧）小脑半球较同侧（左侧）小脑半球降低更明显。免疫组化结果示：双侧小脑半球与正常对照组相比，RGMa蛋白表达均升高，至24 h达最高峰，对侧小脑半球较同侧小脑半球升高更明显。结论：磁共振DTI技术结合RGMa蛋白病理学检查可以发现幕上脑梗死后CCD现象，并可以解释CCD发生的相关机制。

Objective: To detect the change of diffusion parameter in remote regions of the infarct core after middle cerebral artery occlusion(MACO) in rats using diffusion tensor imaging(DTI), to detect the RGMa protein expression of the brain tissue by immunohistochemistry, and to detect the diffusion and pathological changes of the cerebral infarction core area and bilateral cerebellar hemispheres, and to further understand the relevant mechanism of crossed cerebellar diaschisis(CCD). Methods: All the animals were randomly divided into experimental group(n=56) and control group(n=14). After making the successful model, the control group and the experimental group rats underwent MRI at 1 h, 3 h, 6 h, 9 h, 12 h, 24 h and 72 h, and the expression of RGMa protein was detected by immunohistochemistry in the bilateral cerebellar hemispheres of rats. Results: The results of MRI in the experimental group at each time point after MCAO in rats showed that the FA values were all decreased in the bilateral cerebellar hemisphere compared with normal control group, and the FA values were decreased to the lowest at 12 h, and the FA value of the contralateral(right) cerebellar hemisphere was significantly lower than that of the ipsilateral(left) cerebellar hemisphere. The results of immunohistochemistry showed that the expressions of RGMa protein were increased in the bilateral cerebellar hemisphere compared with the normal control group, and the expression were increased to the peak at 24 h, and the expression of the contralateral cerebellar hemisphere was significantly higher than that of the ipsilateral cerebellar hemisphere. Conclusion: The MR DTI combined with RGMa protein pathology can be used to detect the phenomenon of CCD after supratentorial cerebral infarction, and to explain the mechanism of CCD.