Very selective suppression pulses for clinical MRSI studies of brain and prostate cancer

Focal three-dimensional magnetic resonance spectroscopic imaging (3D MRSI) methods based on conventional point resolved spectroscopy (PRESS) localizat ion are compromised by the geometric restrictions in volume prescription an d by chemical shift registration errors. Outer volume saturation (OVS) puls es have been applied to address the geometric limits, but conventional OVS pulses do little to overcome chemical shift registration error, are not par ticularly selective, and often leave substantial signals that can degrade t he spectra of interest. In this paper, an optimized sequence of quadratic p hase pulses is introduced to provide very selective spatial suppression wit h improved B-1 and T-1 insensitivity. This method was then validated in vol unteer studies and in clinical 3D MRSI exams of brain tumors and prostate c ancer. Magn Reson Med 43:23-33, 2000, (C) 2000 Wiley-Liss, Inc.