SPECTRAL EDITING WITH ADIABATIC PULSES

Amplitude- and frequency-modulated pulses, known as adiabatic pulses, can induce uniform flip angles in the presence of extreme B-1 inhomoge neity, which makes them advantageous for in vivo surface-coil studies. This paper describes the conversion of conventional (square pulse-bas ed) spectral-editing sequences into their adiabatic counterparts. Eigh t adiabatic homo- and heteronuclear sequences are experimentally evalu ated for lactate editing. For homonuclear lactate editing, gradient-en hanced multiple-quantum-coherence filtering provides the best overall performance (100% signal recovery with excellent water and lipid suppr ession in a single acquisition). For heteronuclear [3-C-13]lactate edi ting, gradient-enhanced heteronuclear multiple-quantum-coherence filte ring provides the best suppression of unwanted signals in a single acq uisition, whereas J-modulated spin-echo sequences yield maximum sensit ivity. (C) 1995 Academic Press, Inc.