利用非对称基于自旋回波的回波平面成像序列定量测量脑缺血动物模型脑氧代谢的变化  

Quantitative measurement of cerebral oxygen metabolism using asymmetric spin echo version of echo planar imaging sequence in an animal model of ischimia

作　　者：常飞燕 谢晟[1] 于磊[2] 程双娟 张真霞 王武[1] 

机构地区：[1]北京中日友好医院放射科,100029 [2]北京大学第一医院放射科

出　　处：《中华放射学杂志》2016年第4期302-306,共5页Chinese Journal of Radiology

基　　金：国家自然科学基金（81201154）

摘　　要：目的利用非对称基于自旋回波的回波平面成像（ASEEPI）序列测量犬脑缺血模型建模前后脑组织脑氧摄取分数（OEF）值的变化，验证该序列能否反映缺血引起的脑氧代谢的变化。方法采用健康杂种犬12只，先进行基础状态下脑MR扫描，扫描序列包括冠状面T2WI、DWI、MRA以及冠状面ASEEPI及三维伪连续脉冲动脉自旋标记（3DPCASL）序列。然后进行手术解剖分离双侧颈动脉（CA），6只犬仅结扎双侧颈动脉，另6只犬先结扎后栓塞双侧颈动脉。手术1h后再次进行犬脑MR扫描检查，序列同基础状态。扫描结束后将犬处死，完整取出大脑组织做冠状面冰冻切片及2，3，5-氯化三苯基四氮唑（TTC）染色。ASEEPI序列原始数据在工作站Functool软件进行后处理得到OEF图像，在双侧大脑半球各绘制2个等大的ROI，测量基础状态及手术后1h的OEF值。3DPCASL序列在主机Functool软件进行后处理得到脑血流量（CBF）图像，同样绘制ROI，测量基础状态及手术后1h的CBF值。双侧CA结扎犬、双侧CA栓塞犬手术前后测量值的变化采用独立样本t检验分析进行比较；双侧CA结扎犬手术前后、双侧CA栓塞犬手术前后各自测量值采用配对t检验进行比较。分析脑组织切片TFC染色后的着色情况，确定有无梗死发生。结果双侧CA结扎犬手术前后CBF值分别为（59．81±23．59）、（38．56±12．98）ml/（min·100g），双侧CA栓塞犬手术前后CBF值分别为（58．94±18．35）、（28．01±11．41）ml／（min·100g），术后CBF值均较基础状态明显下降（t值分别为8．92和13．42，P值均为0．00），且双侧CA栓塞犬CBF值下降更明显（t=2．92，P=0．00）。双侧CA结扎犬手术前后OEF值分别为0．29±0．02、0．32±0．06，双侧CA栓塞犬手术前后OEF值分别为0．29±0．02、0．35±0．06，术后OEF均较基础状态明显上升（t值分别为-7．21和-4．43，P值均为0．00）�Objective To assess whether asymmetric spin echo version of echo planar imaging （ASE EPI） sequence can reflect cerebral oxygen metabolism by means of the changes in oxygen extraction fraction values before and after surgical operations in the canine model of ischimia. Methods A total of 12 healthy crossbreed dogs were enrolled in this study. All canines underwent cerebral MR imaging including coronal T2WI, DWI, MRA, ASE EPI and 3D PCASL. The bilateral carotid arteries （CA） were separated by surgical operations. The bilateral CA were ligated in 6 dogs, and the other 6 dogs had embolization in ligated bilateral CA. The cerebral MR imaging with the above protocol was repeated at 1 hour after surgical operation for each dog. All dogs were executed when they finished the MR examinations. Then the whole brains of the dogs were taken out for cutting coronal sections and 2, 3, 5-triphenyltetrazolium chloride （TTC） staining. The ASE EPI data were processed by the Functool software in the workstation to generate OEF maps. For measuring the OEF values before and 1 hour after surgical operations, one and the same region of interest （ROI） was respectively placed in the left and right hemispheres on the OEF maps for each dog. 3D PCASL data were processed by the Functool software in the workstation to yield CBF maps. The method for measuring the CBF values before and 1 hour after surgical operations on CBF maps was same as that for measuring on OEF maps, The changes of measurements before and after surgical operations were compared between the dogs with ligated bilateral CA and the dogs with embolization in ligated bilateral CA by using an independent samples t test. The measurements before and after surgical operations were respectively compared in the dogs with ligated bilateral CA and the dogs with embolization in ligated bilateral CA by using a paired t-test. The cutting slices with Trc staining were analysed for determining ischimia. Results The CBF values of the dogs with ligated bilateral CA were （59.81

关 键 词：脑缺血 磁共振成像 动物实验 

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