Techniques for Localisation and Signal Improvement in In Vivo Proton and Phosphorus MR Spectroscopy

Abstract

Magnetic resonance spectroscopy (MRS) is a unique tool providing non-invasive insight into human metabolism. At presence, the major limitations preventing a widespread clinical application of MRS are (i) the intrinsic low sensitivity of MR techniques, and (ii) the poor degree of integration and automation of techniques for localised MRS on commercially available MR scanners. On the other hand, the question for appropriate localisation techniques, exhaustively discussed in the early days of “whole body” MRS, can be considered solved: today, chemical shift resolved spectroscopic imaging (CSI, Brown et al., 1982; Maudsley et al, 1983) techniques have been established for 31P MRS, whereas single-voxel techniques based on the stimulated echo (STEAM; Frahm et al, 1989) or the spin echo (SE; Bottomley, 1982) as well as hybrid techniques, combining CSI and single-voxel techniques are routinely used for 1H MRS at many clinical MR scanners.