A new localization method using an adiabatic pulse, BIR-4.

A new method is described for accomplishing localized spectroscopy with an adiabatic pulse, BIR-4. The method has advantages similar to previously described combinations of outer-volume suppression (OVS) and ISIS, with the additional advantages that localization is achieved with only three radiofrequency pulses and the localization remains accurate even in the presence of intense signals with short relaxation times. This new localization pulse sequence is referred to as integrated OVS-ISIS. Computer simulations, experimental images of the localized volumes, and in vivo 1H spectroscopy measurements demonstrate the high degree of localization achievable with integrated OVS-ISIS.