急性脑缺血表观扩散系数成像的实验研究

用改良的线栓法大脑中动脉阻塞模型,探讨急性脑缺血及再灌注的表现扩散系数成像特点。方法：２０只ＳＤ大白鼠,分为４组：Ａ组（８只）,非再通组,Ｂ、Ｃ、Ｄ组（各４只）,分别于ＭＣＡＯ３０ｍｉｎ、１ｈ、２ｈ后再通,于不同时间点作ＡＤＣ成像和Ｔ２ＷＩ,并测量感兴趣区的ＡＤＣ、相对ＡＤＣ（ｒＡＤＣ）。结果：ＭＣＡＯ后１５ｍｉｎ好出现缺血区ＡＤＣ下降,而Ｔ２ＷＩ最早在栓塞后２ｈ出现异常。６ｈ内缺血区,ＡＤＣ及ｒ

An experimental study on acute cerebral ischemia and reperfusion with diffusion-weighted imaging

Objective:To assess acute cerebral ischemia and reperfusion with apparent diffusion coefficient (ADC) in a modified model of occlusion of middle cerebral artery (MCAO). Methods:20 rats were divided into 4 groups:group A (n=8), non-reperfusion;group B,C,D (n=4 for each),reperfusion at 30m,1h,2h following MCAO.All rats were examined with diffusion imaging and T 2WI at varying time point.ADC,relative ADC (rADC) were measured.Results:ADC decreased in the ipsilateral MCA territory at 15 minutes of MCAO,while hyperintensity was found on T 2WI as early as 2h after MCAO.ADC and rADC of abnormal area continuously declined within 6 hours after MCAO.After reperfusion,abnormal area on DWI recovered entirely or partially in group B and C,but not in group D.The rADCs of the area which could be recovered by reperfusion were significantly lower than those which not be salvaged by reperfusion.Conclusions:ADC imaging is highly sensitive to acute cerebral ischemia and serves as a quantitative,non-invasive imaging modality for evaluating acute cerebral ischemia and reperfusion.