Water suppression in 1H magnetic resonance images by the generation of multiple-quantum coherence

Pulse sequences which generate multiple- and zero-quantum coherence and suppress the detection of single-quantum coherence have ben used to greatly reduce the intensity of the water signal in NMR images. In the experiment, image signals having multiple-quantum behavior add constructively while single-quantum signals, such as the signal arising from water, are canceled. Since the generation of multiple-quantum coherence is only a function of spin-spin coupling, water suppression by this technique is independent of chemical shift. Consequently, suppression of the water resonance in a 1H NMR image can be accomplished in an inhomogeneous magnetic field provided that the excitation profile of the rf pulses is equal for all spins. Furthermore, variations in the T1 and T2 of coupled and uncoupled spins do not affect the efficiency of the multiple-quantum filter.