INTRODUCTION

Nuclear Magnetic Resonance (NMR) involves the measurement of radiofrequency signals arising from transitions between nuclear energy states that are formed when spinning nuclei align with an applied magnetic field. In Magnetic Resonance Imaging (MRI) it is the spatial distribution of protons (eg. hydrogen nuclei and hence water) that are mapped in the 2 or 3 dimensional image. In Magnetic Resonance Spectroscopy (MRS), the concentration of important metabolites are measured in the body, usually from a well defined rectangular volume located relative to the MR image. In both cases, the technique is non-invasive and can be applied repetitively with no harm to the patient. MR scanners are costly (up to several million dollars/pounds) and incorporate a powerful magnet which is usually superconducting.