When the gradient strength is not strong enough to suppress the chemical shift effects, it is possible to apply a numerical deconvolution technique to remove the chemical shift artifacts. The Wiener filter and an apodization function are combined to produce an effective deconvolution method for the NMR images obtained by standard spin-echo NMR imaging technique. In the deconvolution process, an NMR spectrum is utilized which is taken at the same condition as the NMR image but with the phase encoding and the read gradients off.
Juwhan Liu, Antti O. K. Nieminen, and Jack L. Koenig, "Deconvolution of the Chemical Shift Effects in Proton Nuclear Magnetic Resonance Imaging," Appl. Spectrosc. 43, 1260-1264 (1989)