Optimized Shinnar-Le Roux RF 180°pulses in fast spin-echo measurements

Abstract

Optimized Shinnar-Le Roux (SLR) pulses have very good slice profiles with no sidelobes and very small out-of-slice ripples with nearly constant amplitude. In multislice fast spin-echo (FSE) imaging, a better slice definition changes the stimulated echo (STE) and magnetization transfer (MT) contribution on contrast and signal. We investigated the effects of STE and MT on signal and contrast enhancement when optimized 180°SLR pulses are used in multislice FSE measurements. From the results obtained in both phantom and volunteer studies, it can be inferred that using optimized 180°SLR pulses with band-widths larger than that of the conventional 180°sinc-pulse allows significant signal improvement and contrast enhancement.