For the brain, a variety of automated non-iterative shimming methods using phase evolution derived B.sub.0 maps have been reported. These methods assume that there is only a single chemical species contributing to the image. Although true in the brain, lipid contributions from skin, bone marrow and structural fat, may approach or exceed the concentration of water in other organs. In these instances, standard B.sub.0 mapping methods cannot be used due to contributions arising from the lipids. To overcome these limitations the present invention discloses a multi-point B.sub.0 mapping method combined with Dixon imaging to provide fully automated shimming of the human calf.