Introduction

The application of magnetic resonance spectroscopy (MRS) techniques to the study of neuropsychiatric disorders in childhood provides an extraordinary opportunity to advance our understanding of the neurobiological mechanisms underlying these disorders. Recent developments in imaging technology have afforded researchers the capability to examine in vivo not only brain structure but also neurochemistry and functional architecture. This review will focus on the use of MRS. All MR methods (MRS, magnetic resonance imaging (MRI) and functional MRI, (fMRI)) rely on the same basic principles. In the study of human brain, all three of these procedures use the same hardware. Of these techniques, MRS was the first technology to be developed, exploiting the magnetic properties of nuclei with unpaired protons and neutrons. The earliest observations of NMR signals from bulk matter were made independently by Purcell and colleagues (1946) and by Bloch et al. (1946). However, a number of important technical developments were necessary before the first spectra could be obtained from human brain in the 1980s (Krishnan and Doraiswamy, 1997). A glossary of technical terms used in functional neuroimaging is provided at the end of this book (p. 480).

Methods in MRS

The importance of MRS for understanding neuropathologic processes is derived from the information this technique provides regarding the chemical content of the tissue being studied. The application of this technology allows investigators to acquire data that describe both the chemistry and the physical environment of the tissue.