A longitudinal evaluation of diffusion kurtosis imaging in patients with mild traumatic brain injury

Primary objective: To investigate longitudinal diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) changes in white and grey matter in patients with mild traumatic brain injury (mTBI). Research design: A prospective case-control study.

Methods and procedures: DKI data was obtained from 24 patients with mTBI along with cognitive assessments within 10 days, 1 month and 6 months post-injury and compared with age-matched control (n = 24). Fractional anisotropy (FA), mean diffusivity (MD), radial diffusion (λ_r), mean kurtosis (MK) and radial kurtosis (K_r) were extracted from the thalamus, internal capsule and corpus callosum. Main outcomes and results: Results demonstrate reduced Kr and MK in the anterior internal capsule in patients with mTBI across the three visits, and reduced MK in the posterior internal capsule during the 10 day time point. Correlations were observed between the change in MK or K_r between 1-6 months and the improvements in cognition between the 1 and 6 month visits in the thalamus, internal capsule and corpus callosum.

Conclusions: These data demonstrate that DKI may be sensitive in tracking pathophysiological changes associated with mTBI and may provide additional information to conventional DTI parameters in evaluating longitudinal changes following TBI.