Modeling white matter microstructure with fiber ball imaging.

摘要: Abstract Fiber ball imaging (FBI) provides a means of calculating the fiber orientation density function (fODF) in white matter from diffusion MRI (dMRI) data obtained over spherical shell with b-value about 4000 s/mm2 or higher. By supplementing this FBI-derived fODF dMRI acquired for two lower shells, it is shown that several microstructural parameters may be estimated, including axonal water fraction (AWF) and intrinsic intra-axonal diffusivity. This (FBWM) modeling method demonstrated healthy volunteers, results are compared those tract integrity (WMTI) method. Both AWF diffusivity FBWM found to significantly larger than WMTI, values being more consistent recent using isotropic weighting. An important practical advantage only nonlinear fitting required minimization cost just single free parameter, which facilitates implementation efficient robust numerical routines.