大鼠超急性脑梗死弥散-灌注磁共振成像的实验研究

Diffusion-Perfusion MRI in Superacute Cerebral Infarction: An Experimental Study in Rats

目的 应用弥散 灌注磁共振成像技术对改良线栓法制作的鼠大脑中动脉阻塞超急性脑梗死进行实验研究。材料与方法 34只SD大鼠 ,随机分成 5组 ,其中 2只为假手术A组 ,其余按栓塞时间 30分钟、1、3、6小时分成B、C、D、E 4组。A组于 2、2 4小时后 ,B、C、D、E组分别于栓塞后 30分钟、1、3、6小时以及线栓拔出后 2、2 4小时行弥散和灌注成像扫描。结果 假手术A组弥散、灌注成像无异常信号。实验B、C、D、E组均见灌注异常信号且范围无变化 ,弥散高信号区随时间延长而范围增大 ,6小时后与灌注异常信号区一致。栓塞 2小时后T2 WI显示高信号。结论 弥散磁共振成像可显示超急性脑梗死灶大小及其演变规律 ,灌注成像显示脑梗死缺血范围。

Objective To study superacute cerebral infarction with diffusion perfusion MRI in experimental rat model by occluding middle cerebral artery. Materials and Methods The total 34 rats were randomly divided into 5 groups. Group A (n=2) was control group and was used as sham operated rats. The remaining rats were divided into group B, C, D and E (n=8 each) with the middle cerebral artery occlusion time of 30 minutes, 1, 3 and 6 hours, respectively. At the end of the scheduled occlusion time, all rats of group B, C, D, and E were studied with diffusion weighted imaging (DWI) and perfusion imaging (PI). DWI and PI were repeated in rats of above groups at 2 and 24 hours after reperfusion of middle cerebral artery. DWI and PI were carried out in rats of group A at 2 and 24hours after the procedure.Results In sham operated rats of group A, no abnormal signal was seen on DWI and PI. In rats of group B, C, D and E, abnormal signal was seen on PI. The high intensity signal area on DWI enlarged with the time, and became the same size as the abnormal signal area on PI after 6 hours. High signal was seen on T 2WI in only 2 hours after the occlusion of middle cerebral artery.Conclusion The size, extent and development of superacute cerebral infarction can be well demonstrated on DWI, while the area of ischemia can be displayed on PI.