Astafiev Serguei V, Wen Jie, Brody David L, Cross Anne H, Anokhin Andrey P, Zinn Kristina L, Corbetta Maurizio, Yablonskiy Dmitriy A
Department of Radiology, Washington University in St. Louis, 660 S. Euclid Ave, Campus Box 8225, St. Louis, MO.
Department of Psychiatry, Washington University in St. Louis, 660 S. Euclid Ave, Campus Box 8134, St. Louis, MO.
Mil Med. 2019 Mar 1;184(Suppl 1):218-227. doi: 10.1093/milmed/usy394.
It is widely accepted that mild traumatic brain injury (mTBI) causes injury to the white matter, but the extent of gray matter (GM) damage in mTBI is less clear.
We tested 26 civilian healthy controls and 14 civilian adult subacute-chronic mTBI patients using quantitative features of MRI-based Gradient Echo Plural Contrast Imaging (GEPCI) technique. GEPCI data were reconstructed using previously developed algorithms allowing the separation of R2t*, a cellular-specific part of gradient echo MRI relaxation rate constant, from global R2* affected by BOLD effect and background gradients.
Single-subject voxel-wise analysis (comparing each mTBI patient to the sample of 26 control subjects) revealed GM abnormalities that were not visible on standard MRI images (T1w and T2w). Analysis of spatial overlap for voxels with low R2t* revealed tissue abnormalities in multiple GM regions, especially in the frontal and temporal regions, that are frequently damaged after mTBI. The left posterior insula was the region with abnormalities found in the highest proportion (50%) of mTBI patients.
Our data suggest that GEPCI quantitative R2t* metric has potential to detect abnormalities in GM cellular integrity in individual TBI patients, including abnormalities that are not detectable by a standard clinical MRI.
轻度创伤性脑损伤（mTBI）会导致白质损伤，这一点已被广泛认可，但mTBI中灰质（GM）损伤的程度尚不清楚。
我们使用基于磁共振成像的梯度回波多元对比成像（GEPCI）技术的定量特征，对26名平民健康对照者和14名平民成年亚急性-慢性mTBI患者进行了测试。GEPCI数据使用先前开发的算法进行重建，该算法可将R2t*（梯度回波MRI弛豫率常数的细胞特异性部分）与受血氧水平依赖（BOLD）效应和背景梯度影响的整体R2*分离。
单受试者体素级分析（将每位mTBI患者与26名对照受试者的样本进行比较）显示，在标准MRI图像（T1加权和T2加权）上不可见的GM异常。对低R2t*体素的空间重叠分析显示，多个GM区域存在组织异常，尤其是额叶和颞叶区域，这些区域在mTBI后经常受损。左侧后岛叶是在最高比例（50%）的mTBI患者中发现异常的区域。
我们的数据表明，GEPCI定量R2t*指标有潜力检测个体TBI患者GM细胞完整性的异常，包括标准临床MRI无法检测到的异常。
