Magnetic resonance spectroscopy in schizophrenia: Methodological issues and findings - Part I

Our knowledge of the biological basis of schizophrenia has significantly in creased with the contribution of in vivo proton and phosphorus magnetic res onance spectroscopy (MRS) a noninvasive tool that can assess the biochemist ry from a localized region in the human body. Studies thus far suggest alte red membrane phospholipid metabolism at the early stage of illness and redu ced N-acetylaspartate, a measure of neuronal volume/viability in chronic sc hizophrenia. Inconsistencies remain in the literature, in part due to the c omplexities in the MRS methodology. These complexities of in vivo spectrosc opy make it important to understand the issues surrounding the design of sp ectroscopy protocols to best address hypotheses of interest This review add resses these issues, including I) understanding biochemistry and the physio logic significance of metabolites; 2) the influence of acquisition paramete rs combined with spin-spin and spin-lattice relaxation effects on the MRS s ignal; 3) the composition of spectral peaks and the degree of overlapping p eaks, including the broader underlying peaks; 4) factors affecting the sign al-to-noise ratio; 5) the various types of localization schemes; and 6) the objectives to produce accurate and reproducible quantification results. Th e ability to fully exploit the potentials of in vivo spectroscopy should le ad to a protocol best optimized to address the hypotheses of interest. (C) 2000 Society of Biological Psychiatry.