Incorporating susceptibility effects into the Standard Model of diffusion in white matter

Estimating parameters of the Standard Model (SM) of white matter (WM) is an ill-posed problem (WM). To overcome this degeneracy, models extensions have been proposed adding echo-time dependent information. Here we investigate the feasibility of incorporating our analytical solution for the frequency shift from white matter axons accounting for magneto-structural anisotropy along with an empirical orientation dependence of relaxation into SM parameter estimation. This may also help achieving rotation-free mapping of susceptibility-related parameters using diffusion MRI instead of the impractical sample rotation in the scanner.