1. A system comprising: a non-transitory memory storing computer-executable instructions; and a processor that executes the computer-executable instructions to at least: receive diffusion magnetic resonance imaging (dMRI) data; determine a diffusion tensor (DT) for the dMRI data; determine a diffusional kurtosis tensor (DKT) for the dMRI data; and determine a kurtosis diffusion orientation distribution function (dODF) for the dMRI data based on the DT and the DKT, wherein the kurtosis dODF extends a Gaussian approximation of the DT to include non-Gaussian corrections of the DKT, wherein the kurtosis dODF (ψ α,K ({circumflex over (n)})) is represented by the following equation: ψ α , K ⁡ ( n ^ ) = ψ α , G ⁡ ( n ^ ) ⁢ { 1 + 1 24 ⁢ ∑ i , j , k , l ⁢ [ 3 ⁢ U ij ⁢ W ijkl ⁢ U kl - 6 ⁢ ( α + 1 ) ⁢ U ij ⁢ W ijkl ⁢ V kl + ( α + 1 ) ⁢ ( α + 3 ) ⁢ V ij ⁢ W ijkl ⁢ V kl ] } , where ⁢ ⁢ V ij ≡ ( U ⁢ n ^ ) i ⁢ ( U ⁢ n ^ ) j n ^ T ⁢ U ⁢ n ^ , wherein ψ α,G ({circumflex over (n)}) represents the Gaussian dODF, U represents a dimensionless tensor equal to the product of the mean diffusivity and the inverse of the DT, W represents the DKT, α represents a radial weighting power, i, j, k, and l are indices carried out from 1 to 3, and {circumflex over (n)} is a unit direction vector.