Higher orders diffusion MRI metrics along with enlarged perivascular spaces as markers in chronic mild traumatic brain injury

Motivation: : Inconsistent findings of white matter (WM) alterations in chronic mild traumatic brain injury (mTBI) across studies Goal(s): To demonstrate higher orders diffusion MRI metrics along with assessment of enlarged perivascular space (ePVS) can reveal mixed pattern of WM alterations in chronic mTBI Approach: We quantitated ePVS loads and applied non-Gaussian diffusion MRI to assess WM disruption after mTBI. Results: The findings of increased kurtosis fractional anisotropy and decreased free water volume fraction over the frontal WM, suggesting astrogliosis with neuroplasticity. Furthermore, decreased orientation distribution index with greater ePVS loads over the parietal region suggest loosely WM with neuronal loss after a remote mTBI. Impact: Higher model diffusion MRI along with ePVS loads assessment should be considered as a choice of option in evaluating subtle white matter alterations in mild traumatic brain injury due to heterogeneous injury and repair mechanisms after a remote brain injury.