Fat suppressed MR imaging can be achieved by selectively saturating lipid protons, just before applying a conventional spin-echo rf pulse sequence. The difference in the Larmor frequency between fat and water protons is only 3.5 ppm, so that the frequency response of the suppressing pulse, or pulses, has to be carefully designed. The choice of suitable binomial and modified trains of hard rf pulses was investigated by computer simulation, phantom testing and T1 weighted spin-echo imaging of a normal volunteer's optic nerve at 0.5 T.