急性弥漫性轴索损伤磁共振弥散张量成像实验研究  

Experimental study of diffusion tensor imaging in acute diffuse axonal injury

作　　者：何海涛[1] 黎海涛[2] 黎川[2] 王怡[2] 

机构地区：[1]解放军第82医院放射科,江苏淮安223001 [2]第三军医大学西南医院放射科,重庆400038

出　　处：《中华神经外科疾病研究杂志》2008年第3期212-215,共4页Chinese Journal of Neurosurgical Disease Research

基　　金：国家重点基础研究发展规划基金资助项目(2005CB522602)

摘　　要：目的通过对猫急性弥漫性轴索损伤(DAI)磁共振弥散张量成像(DTI)与病理的对比研究,探讨DTI对急性DAI的诊断价值。方法共选取22只猫,其中10只用于常规MR I及DTI扫描,以最大角加速度(6.43±0.15)×105rad/s2制成急性DAI模型,连续观察DAI前及DAI后3 h、6 h、24h、48 h、72 h 6个时相点,另于上述相同6个相点,分别选取6只猫用于嗜伊红(HE)及嗜银染色、6只猫用于透射电镜观察。结果常规MR I显示蛛网膜下腔出血1例、硬膜外或硬膜下出血2例、脑挫裂伤2例、脑室内出血1例、同时显示蛛网膜下腔出血和脑挫裂伤2例、同时显示硬膜下出血和脑实质内点状出血2例。DTI显示猫DAI后表观弥散系数(ADC)值降低,于48 h达最低,72 h轻度回升(但仍低于DAI前),各向异性(FA)值明显降低,72 h达最低。HE、嗜银染色及透射电镜显示血管通透性增加、细胞肿胀,轴索肿胀、断裂、轴索球形成。结论DTI可以在活体水平无创的观察DAI后脑水肿及轴索的病理改变。Objective To explore the diagnostic value of diffusion tensor imaging （DTI） in acute DAI comparing to the histopathological changes. Methods Twenty-two cats were involed in the study and cat DAI models were made with the angular acceleration of （6.43±0. 15）×10^5rad/s^2 by a rotating device. Ten of them undertook routine MRI and DTI before traumatic event and at the time points of 3 h, 6 h, 24 h, 48 h, 72 h after traumatic event. Six cats were observed under HE and silver staining light microscope and another 6 cats under transmission electron microscope at the same time points. Results The routine MRI scans showed that there were 1 case of subarachnoid hemorrhage （SAH）, 2 cases of subdural hemorrhage （SDH） or extradural hemorrhage （EDH）, 2 cases of contusion, 1 case of intravetricular hemorrhage （IVH）, 2 cases of SAH and contusion, and 2 cases of SDH and punctate hemorrhage （PH）. The decrease of apparent diffusion coefficient （ADC） values was observed after DAI, reached the minimum at 48 h and then increased slightly at 72 h. The gradual decrease in fractional anisotropy （FA） value happened after DAI and reached the minimum value at 72 h. Vasogenic brain edema, cytotoxic brain edema, axon swelling, axon disintegration, retraction ball and neuronal changes were found by histopathological observation. Conclusion DTI can sensitively and noninvasively reveal the changes of brain edema and axonal structure in vivo after DAI.

关 键 词：弥漫性轴索损伤 脑水肿 弥散张量成像 表观弥散系数 各向异性值 

分 类 号：R651.15[医药卫生—外科学] R445.2[医药卫生—临床医学]