Abstract: Systems and methods facilitating high definition fiber tracking are disclosed. These systems and methods can utilize a directional Axonal Volume (dAV) value that can quantify the direction and volume of anisotropic water diffusion in axons to assess brain connection integrity. dAV provides a robust and anatomically interpretable measurement of connectivity strength of axon tracts. One method include receiving diffusion magnetic resonance imaging (dMRI) data, quantifying a vector axonal directional diffusion axon volume while removing extracellular isotropic water, segmenting fiber tracks from the data, voxelizing the fiber tracks into voxels, determining voxel dAV values for each voxel and directions, and determining fiber dAV values for each fiber track based on voxel dAV values. This non-invasive method can measure strength and integrity of brain tracts.