弥漫性轴索损伤大鼠易损区微结构损伤7．0TMRI定量研究  

Quantitative evaluation of micro-structural damage of vulnerable areas in rats with diffuse axonal injury with 7.0T MRI

作　　者：李甲[1] 李雪元[1] 滕皋军[2] 冯东福[1] 顾磊[1] 陈二涛[1] 朱志安[1] 

机构地区：[1]上海交通大学医学院附属第三人民医院神经外科,201900 [2]东南大学附属中大医院放射科、江苏省分子影像与功能影像重点实验室

出　　处：《中华创伤杂志》2011年第7期643-647,共5页Chinese Journal of Trauma

基　　金：上海市科委攻关计划资助项目（064119639）;上海交通大学医学院基金资助项目（09XJ21072）;上海交通大学医工结合专项资助项目（YG08PETMSl9）

摘　　要：目的探讨弥漫性轴索损伤（diffuse axonal injury，DAI）大鼠脑组织微结构损伤的空间分布特征，定量评估易损区轴索损伤的程度。方法使用7．0TMRI对DAI组（20只）和假损伤对照组（15只）大鼠进行扫描，合成弥散张量成像（diffusion tensor imaging，DTI）参数图并计算各易损区的参数值。免疫组化染色检测各易损区B—APP的表达情况，使用IPP软件定量评估轴索损伤的严重程度。结果与对照组大鼠比较，DAI大鼠部分各向异性（fractional anisotropy，FA）、轴向弥散系数（axial diffusivity，AD）图可见胼胝体局部信号缺损或减低；脑干、胼胝体FA值和AD值显著性降低（P〈0．05）；各易损区免疫组化染色的累积吸光度（IOD）值均显著性增高（P〈0．01），最高为脑干（P〈0．05）；各易损区标化后FA、AD、表观弥散系数（apparent diffusion Coefficient，ADC）与IOD呈负相关关系（P〈0．05）。结论DTI能够检测DAI易损区微结构的非可视病变，活体、定量地早期评估轴索损伤程度。Objective To observe the spatiotemporal characteristics of the micro-structural injury in a rat model of diffuse axonal injury （DAI） and quantitatively assess the axonal injury severity in the vulnerable areas. Methods The 7.0 T MRI was performed in rats in DAI group （ n = 20） and control group （n = 15 ） to synthesize the diffusion tensor imaging （DTI） parameter map and calculate the parameter value of the vulnerable areas. Immunohistochemistry was used to detect β-APP expression in the vul- nerable areas and the IPP software to quantitatively assess the axonal injury severity. Results Compared with the control group, FA and AD maps showed local signal defection or reduction in the corpus callosum and their values decreased significantly in the brain stem and corpus callosum in the DAI group （P 〈0.01 ）. The integrated optical density （IOD） value of the vulnerable areas in the DAI group was significantly higher than that of the control group （ P 〈 0.01 ） , with the highest level in the brain stem （P 〈 0.05 ）. The normalized FA, AD and ADC in the vulnerable areas were correlated negatively with the IOD （P 〈 0.05）. Conclusion DTI can detect invisible micro-structural injury in the vulnerable areas and quantitatively assess the axonal injury severity in vivo in the early stage.

关 键 词：弥漫性轴索损伤 弥散张量成像 免疫组织化学 累集光密度值 感兴趣区 

分 类 号：R686[医药卫生—骨科学]