A better understanding of white matter tract damage in patients with diffuse axonal injury (DAI) and mild traumatic brain injury (MTBI) is important to obtain an objective basis for sequelae. The purpose of this study was to clarify the characteristics of white matter tract degeneration in DAI and MTBI using automated tractography. T1-weighted and diffusion tensor imaging (DTI) was performed on seven DAI and seven MTBI patients as well as on nine healthy subjects. Automated probabilistic tractography analysis was performed using FreeSurfer and TRACULA (tracts constrained by underlying anatomy) for the reconstruction of major nerve fibers. We investigated the difference between DTI quantitative values in each white matter nerve fiber between groups and attempted to evaluate the classification accuracy of DAI and MTBI using receiver operator curve analysis. Both DAI and MTBI appeared to exhibit axonal degeneration along the nerve fiber tract in a scattered manner. The mean diffusivity of the ampulla of the corpus callosum was significantly higher in DAI than that in MTBI patients, suggesting axonal degeneration of the corpus callosum in DAI patients. Using mean diffusivity of the right cingulum-angular bundle, DAI and MTBI could be discriminated with an area under the curve of 94%. Both DAI and MTBI exhibited scattered axonal degeneration; however, DAI appeared to exhibit more pronounced axonal degeneration in the ampulla of the corpus callosum than MTBI. Our results suggest that DAI and MTBI can be accurately distinguished using DTI.

中文翻译：

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自动纤维束成像观察弥漫性轴突损伤和轻度创伤性脑损伤中的白质变性。

更好地了解弥漫性轴突损伤（DAI）和轻度创伤性脑损伤（MTBI）患者的白质束损伤对于获得后遗症的客观依据非常重要。本研究的目的是利用自动纤维束成像技术阐明 DAI 和 MTBI 中白质纤维束变性的特征。对 7 名 DAI 和 7 名 MTBI 患者以及 9 名健康受试者进行了 T1 加权和弥散张量成像 (DTI)。使用 FreeSurfer 和 TRACULA（受基础解剖结构限制的纤维束）进行自动概率纤维束成像分析，以重建主要神经纤维。我们研究了各组之间每个白质神经纤维的 DTI 定量值之间的差异，并尝试使用受试者工作曲线分析来评估 DAI 和 MTBI 的分类准确性。DAI 和 MTBI 似乎都沿着神经纤维束以分散的方式表现出轴突变性。DAI 患者胼胝体壶腹部的平均扩散率显着高于 MTBI 患者，提示 DAI 患者胼胝体轴突变性。使用右扣带回角束的平均扩散率，可以用 94% 的曲线下面积区分 DAI 和 MTBI。DAI 和 MTBI 均表现出分散的轴突变性；然而，DAI 似乎比 MTBI 胼胝体壶腹部表现出更明显的轴突变性。我们的结果表明，使用 DTI 可以准确地区分 DAI 和 MTBI。