31P-{1H} echo-planar spectroscopic imaging of the human brain in vivo

Abstract

Echo-planar spectroscopic imaging (EPSI) is one of the fastest spectroscopic imaging (SI) methods. It has been applied to 1H MR spectroscopy (MRS) studies of the human brain in vivo. However, to our knowledge, EPSI with detection of the 31P nucleus to monitor phosphorus-containing neurometabolites has not yet been considered, in this work, eight different 31P-{1H} EPSI sequence versions with spectral widths ranging from 313 Hz to 2.27 kHz were implemented on a clinical 1.5T wholebody MR tomograph. The sequence versions utilized the heteronuclear nuclear Overhauser effect (NOE) for 31P signal enhancement. The sensitivity observed in experiments with model solutions was in good agreement with theoretical predictions. In vivo measurements performed on healthy volunteers (N = 16) demonstrated the feasibility of performing two-dimensional (2D) 31P-(1H) EPSI in the human brain, and the technique enabled fast acquisition of well-resolved localized spectra. © 2007 Wiley-Liss, Inc.