Figure 4.

image estimates from a 256×256 ankle using a single-channel birdcage coil; inaccurate field map estimates in the 1× voxel-independent (VI) method cause water-fat swaps (see outlined regions in VI images); estimates using the proposed method at 2× and 2.5× avoid local minima field map solutions resulting in proper water-fat separation; field map colorbar is in Hertz (Hz);