Figure 2.

(a) The total magnetic susceptibility of myelin can be expressed as the summation of two components: an isotropic component, χ _i and the anisotropic component, χ _a. (b, c) Tensor formulations for χ _i and χ _a in the unrotated frame. (d, e) Orientations of the longitudinal tensor component χ _|| with H is plotted about the azimuth (∠ϕ) for two geometric cases: a nested cylinder and a nested elliptical fiber model. Longitudinal axes of the fibers are assumed to be orthogonal to H (∠θ = π/2); perpendicular cross‐sections are shown. (f–i) Isotropic and anisotropic fields corresponding to the nested cylinder (f, g) and elliptical geometries (h, i).