Assessment of Microstructural White Matter Changes During Early Development with Non-Gaussian Diffusion MRI

Els Fieremans¹, Vitria Adisetiyo¹, Amir Paydar¹, Hetal Sheth¹, John Nwankwo¹, Jens H. Jensen, ¹², Sarah Milla¹

White matter microstructural changes during the first two years of healthy brain development are characterized in terms of non-Gaussian diffusional kurtosis imaging (DKI) parameters. The observed significant non-linear age-related changes in the DKI-parameters suggest an increased sensitivity to brain maturation as compared to standard Gaussian diffusion tensor imaging (DTI). In addition, specific measures of white matter integrity can be derived from DKI, of which significant age-related changes were detected for the axonal water fraction and tortuosity, both markers for myelination, while the intracellular and extracellular diffusivities do not change appreciably in normal brain development.