弥散张量成像基于体素水平的定量分析在脑震荡综合征中的初步应用

The Preliminary Application of the Voxel-Based Quantitative Analysis for Diffusion Tensor Imaging in Post Concussion Syndrome

目的：探讨弥散张量成像（diffusion tensor imaging, DTI）基于体素水平的定量分析在轻度创伤性脑损伤（mild traumatic brain injury, mTBI）早期脑震荡综合征（post concussion syndrome, PCS）中的应用，以期能够通过在体检测在病理层面上对mTBI早期PCS的病理机制加以阐述。方法选择临床确诊且常规影像学检查（CT平扫及常规MRI）阴性的mTBI早期（伤后24 h内）PCS患者17例，并选取年龄、性别、受教育程度等方面与病例组相匹配的正常对照组13名，所有病例组及对照组均行常规MRI检查及DTI检查。所得DTI检查数据应用FSL软件包分别利用部分各向异性和平均弥散率参数对病例组与对照组差异显著性进行基于体素水平的组间多对象统计分析，最后将图像后处理结果以伪彩图方式直观显示。结果mTBI早期PCS病例组与正常对照组相比，右额枕束上部、左额枕束上后部、胼胝体体部、左上纵束近颞部及左下纵束、中脑等区域脑白质FA值升高，左额枕束后部、胼胝体体部、右内囊后肢、中脑及脑桥左侧部等区域脑白质M D值降低。结论DTI基于体素水平的定量分析可以从影像学角度为mTBI早期PCS的脑实质内微结构损伤提供在体病理证据，纤维轴索损伤以细胞毒性水肿、局部炎性反应为主。

Objective To study the application of the voxel-based quantitative analysis for diffusion tensor imaging (DTI) in the post concussion symptoms (PCS) after mild traumatic brain injury (mTBI), to explore the pathogenesis of the PCS early after mTBI vivo. Methods 17 clinical diagnosised mTBI patients at early stage (within 24 hours after injury) were selected, whose conventional imaging scans (CT and conventional MRI) were negative as well as 13 normal controls whose age, gender and education were matched. The conventional MRI and DTI examination was performed for all patients and controls. The voxel-based statistical analysis between the case group and the control was performed using the parameters of fractional anisotropy (FA) and mean diffusivity (MD) separately, which resulted from the DTI data with FSL package, ultimately, the final processing results was visually displayed in pseudo-color composite image. Results Comparing patients with controls, FA was increased in the right superior fronto-occipital fasciculus, the latter part of the left superior fronto-occipital fasciculus, the body of the corpus callosum, the temporal part of the superior longitudinal fasciculus and the inferior longitudinal fasciculus, as well as the mesencephalon, while MD was decreased in the latter part of the left superior fronto-occipital fasciculus, the body of the corpus callosum, the posterior limb of the right internal capsule, the mesencephalon and the pons plpontes. Conclusion The cytotoxic oedema and localized inflammatory responses prevail in the acute stage of the injury of neuraxon for the mTBI patients. The voxel-based quantitative analysis for DTI imaging can provide objective evidence of microstructural brain injury as a pathological substrate of the PCS.