The current status of magnetic resonance spectroscopy--basic and clinical aspects.

Magnetic resonance (MR) spectroscopy is a well-established method of chemical analysis in which the magnetic moment and radio-frequency emission characteristics of each atom and molecule are subjected to a high-intensity magnetic field. This method is now established as a noninvasive way of studying metabolism in vivo. With the development of wide-bore, high field (1.5 tesla or above) magnets, studies of human metabolism are now possible. Most metabolic MR spectroscopic studies have focused on the phosphorus 31 nucleus. Spectra can be obtained from phosphorylated metabolites such as adenosine triphosphate, phosphocreatine, inorganic phosphate and sugar phosphate. In addition, (31)P nuclear magnetic resonance spectra can provide a continuous monitor of the intracellular pH. The other nuclei used for metabolic studies are hydrogen 1, carbon 13 and, to a lesser extent, sodium 23. Much additional research is required before an assessment can be made of the extent to which MR spectroscopy can be used to provide diagnostically useful information. The noninvasive biochemical approach to human metabolism may involve as-yet-undiscovered metabolic features of disease processes.