1. A method for mapping tissue magnetic susceptibility, the method comprising: acquiring magnetic resonance (MR) images acquired at multiple echo times, wherein the MR images correspond to a subject comprising at least two species of protons, and wherein each species has a different chemical shift in its respective resonance frequency; determining, for each species, an estimated chemical shift value; determining an estimated map of magnetic field inhomogeneity based on the estimated chemical shift values; determining an estimated susceptibility distribution of the subject and an error of each estimated chemical shift value based on the estimated map of magnetic field inhomogeneity and prior information regarding the subject; generating an image of the subject based on the estimated susceptibility distribution.