MR扩散加权成像对脑弥漫性轴索损伤的诊断价值

目的:探讨磁共振扩散加权成像在脑弥漫性轴索损伤诊断中的应用价值.方法:对13例临床诊断为弥漫性轴索损伤的脑外伤患者磁共振检查资料进行回顾性分析.结果:扩散加权成像对弥漫性轴索损伤出血性病灶和水肿性病灶检出均很敏感,尤其是对小出血灶和小水肿灶的检出能力显著超过自旋回波序列.扩散加权成像对小出血灶有独特优势,其特征性表现是斑点状低信号周围有水肿环,而且通过消除脑脊液信号,扩散加权成像能更好显示胼胝体水肿灶.讨论:与自旋回波序列比较,磁共振扩散加权成像能更加敏感地检出脑内小病灶,对脑弥漫性轴索损伤的诊断显示出更高的应用价值.

Role of Diffusion Weighted Imaging for the Diagnosis of Diffuse Axonal Injury of Brain

Objective:To investigate the value of MR diffusion weighted imaging (DWI) for the diagnosis of diffuse axsonal injury (DAI) of brain.Methods:Of 13 patients having brain trauma,with clinical diagnosis as diffuse axsonal injury (DAI),the magnetic resonance imaging data were retrospectively analyzed.Results:DWI is sensitive in detecting hemorrhagic and edematous lesion in DAI.Especially the detectability of DWI for the small hemorrhagic and edematous lesion is markedly superior than that of spin echo sequence T_1WI and T_2WI.The characteristic manifestations of small hemorrhagic lesion were low signal intensity spot with surrounding edematous halo.After eliminating signal of cerebral spinal fluid,edematous lesion of corpus callosum can be displayed by DWI more clearly.Conclusion:Compared with spin echo sequence,diffusion weighted imaging of MRI is more important in the diagnosis of DAI by its high sensitivity in detecting small brain lesion.