Improvements in specificity by non-Gaussian diffusion modeling and double diffusion encoding (DDE) to characterize axonal injury

Diffusion MRI techniques that extend beyond diffusion tensor imaging (DTI) – including acquisition strategies and advanced modeling – could provide more specific tools to probe abnormalities in disease or injury states. To evaluate similarities and distinctions across several prominent diffusion MRI strategies in the context of injury, we acquired multi-shell diffusion weighted images (DWIs) and double diffusion encoded (DDE) DWIs in healthy and injured ferret spinal cords. Scalar metrics from DTI, diffusion kurtosis imaging (DKI), mean apparent propagator MRI (MAP-MRI) and DDE-based axonal modeling were directly compared to reveal the ways in which each approach can specify key features of cellular alterations.