i i i i i i t j t f j t jR j t f j t R t j t f j i e where W and F denote the water and the fat components in this pixel, respectively. ∆ f is the chemical shift of fat with respect to water. ψ represents the Bo field inhomogeneity at this pixel. We have used R2* ( = 1/T2*) for convenience. As can be seen, with the "complex field map" π ψ ψ 2 / ˆ * 2 jR + = , the above equation is similar to the IDEAL signal model (2), and a simple modification to the IDEAL reconstruction can be used. The R2* map is simply determined from the imaginary part of ψˆ , which is estimated iteratively (2). The source signals then are demodulated by ψˆ , correcting for both B0 field inhomogeneity and T2* decay, and final water-fat decomposition is achieved with a linear least squares inversion (2). Methods Phantom studies were performed to demonstrate the T2*-IDEAL algorithm. Acetone was used as an alternative for fat as it mixes well with water. The chemical shift of acetone was measured by spectroscopy and determined to be -155 Hz at 1.5 Tesla. Water and acetone were mixed in six 50ml tubes, which were then doped with varying concentrations of Feridex IV ®