Frequency-dependent diffusional kurtosis is sensitive to white matter damage following rotational mild TBI

Motivation: Diffusion MRI (dMRI) is commonly used to examine microstructural changes following mild traumatic brain injury (mTBI), but there are inconsistencies in reports of brain regions affected. Goal(s): We examine how injury kinematics play a role in brain regions affected using advanced dMRI to disentangle various co-occurring microstructural changes. Approach: Use a clinically relevant rotational mTBI model in humanized mice, paired with an advanced oscillating gradient dMRI acquisition, to examine orientation-dependence of tract damage. Results: We show tracts oriented within the rotation plane exhibit more microstructural alterations as measured using dMRI and validated with histology. Advanced dMRI reveals changes not detectable with conventional techniques. Impact: Our results demonstrate that white matter microstructural changes are dependent on mTBI kinematics and thus impact dynamics should be considered when interpreting mTBI studies. Advanced dMRI improves microstructural specificity, which is particularly important when examining conditions with co-occurring microstructural changes.