1. A method of determining a set of parameter estimates for an incoherent motion model from diffusion-weighted magnetic resonance data of a portion of a biological body, the method comprising: (A) determining a first set of parameter estimates for a plurality of voxels associated with one or more images based, at least in part, on the diffusion-weighted magnetic resonance data; (B) determining a second set of parameter estimates by stochastically perturbing the first set of parameter estimates; (C) determining a third set of parameter estimates based, at least in part, on the first set of parameter estimates and the second set of parameter estimates; (D) determining whether at least one criterion associated with the third set of parameter estimates is satisfied; (E) performing acts (B)-(C) using the third set of parameter estimates as the first set of parameter estimates if the at least one criterion is not satisfied; and (F) outputting an indication of the third set of parameter estimates if the at least one criterion has been satisfied.