A Multi-echo Acquisition Method with Reduced Echo Spacing for Robust IDEAL Water-Fat Decomposition at 3T

images from 6-pt IDEAL reconstruction, and the R2* map (c) from 6-pt T2*-IDEAL reconstruction. The echo spacing was 1.3ms (1.1π). Uniform water-fat decomposition was achieved. Figure 1 (left): IDEAL cost functions for two sets of echo times. The purpose of the IDEAL iteration is to search for the minimum (0Hz in this example) of the cost function curves. To avoid converging to local minima, the initial guess needs to be within the marked tolerance zone. In general, a shorter echo spacing is associated with a bigger tolerance zone, thus offering more reliable decomposition.