In contrast, DTI can assess structural networks by quantifying the diffusion of water molecules in neural tissue, indicating white matter structural organization and integrity. We compared four scalar diffusion measurements: (i) fractional anisotropy (FA), which reflects directional coherence of diffusion motion; (ii) mean diffusivity (MD), quantifying the average magnitude of diffusion motion; (iii) axial diffusivity (AD), reflecting diffusion along the axis of white matter fibers; and (iv) radial diffusivity (RD), indicating diffusion perpendicular to the axis of white matter fibers.
