摘要
目的 用改良的线栓法制作大脑中动脉阻塞（ＭＣＡＯ） 动物模型，探讨急性脑缺血及再灌注的磁共振扩散加权成像（ＤＷＩ） 的特点。方法 １８ 只ＳｐｒａｇｕｅＤａｗｌｙ 大白鼠，随机分为４ 组：Ａ 组（６ 只），非再通组；Ｂ、Ｃ、Ｄ组（ 各４ 只） ，分别于ＭＣＡＯ３０ 分钟、１ 小时、２ 小时后再通，于不同时间点作ＤＷＩ和Ｔ２ＷＩ，通过后处理得到表观扩散系数（ＡＤＣ）像并计算感兴趣区的ＡＤＣ、相对ＡＤＣ（ｒＡＤＣ）及ＤＷＩ上高信号区的面积。结果 ＭＣＡＯ后１５ 分钟即在ＤＷＩ上出现缺血区高信号，而Ｔ２ＷＩ示正常；随时间延长，信号强度逐渐增加，范围扩大，６ 小时内缺血区ＡＤＣ及ｒＡＤＣ呈不断下降趋势。ＭＣＡＯ３０ 分钟及１ 小时后再通者，ＤＷＩ上缺血区高信号完全或部分恢复正常；而ＭＣＡＯ２ 小时再通者，缺血区均无缩小。结论 ＤＷＩ对急性脑缺血非常敏感，为研究脑缺血及再灌注提供了定量的、无创的成像方法。
Objective To assess acute cerebral ischemia and reperfusion with magnetic resonance diffusion weightedimaging (DWI) in a modified modelofocclusion of middle cerebralartery(MCAO)- Methods 18 rats were divided into 4 groups:group A( n = 6) ,non reperfusion; group B,C,D(n = 4 for each) , reperfusionafter 30 min,1 h,2 h of MCAO- All rats were examined with DWIand T2WIat different time intervals- Apparentdiffusion coefficient(ADC) images were obtained- ADC,relative ADC(rADC) and area of hyperintensityon DWIwere measured- Results DWIdemonstrated increased signalintensity in the ipsilateral MCAterritory at15 minutes after MCAO- Theipsilateral DWIsignalintensity increased further and the area of hyperintensityslightlyincreased withtime- ADCandrADCofabnormalareacontinuouslydeclined within6 hoursof MCAO- Afterreperfusion,abnormalarea on DWIrecovered entirely or partially in group Band C,but notin group D- Conclusions DWIbeing highly sensitive to acute cerebralischemia is a quantitative,non invasive imaging modalityforevaluating acute cerebralischemia and reperfusion-
出处
《中华放射学杂志》
CAS
CSCD
北大核心
1999年第10期662-666,共5页
Chinese Journal of Radiology
关键词
脑缺血
再灌注
磁共振成像
扩散
评价研究
Cerebral ischemia Animals,laboratory Reperfusion Magnetic resonance imaging Diffusion Evaluation studies
