Applications of Proton MRS to Study Human Brain Metabolism

Magnetic resonance spectroscopy (MRS) provides information that is rarely obtainable by other noninvasive means, or even by invasive methods using radioactive labels. For example, it provides the means to monitor in time and in space changes in various metabolic pools and allows one to think in terms of the biochemistry of these pools. In this sense, MRS is quite unique, and, although it cannot be said to be highly specific in diagnosing individual diseases, it nevertheless enables changes in many critical and characteristic parameters to be observed noninvasively for a broad range of metabolic abnormalities. By its nature MRS lends itself more toward the evaluation of diffuse brain diseases rather than that of focal lesions. For example, typical applications of MRS have been (1) to assess the regional distribution of neuronal dysfunction or death, (2) to evaluate distributions in the oxidative state of the brain, or (3) to detect regions of membrane abnormality. This list is growing as new MRS technology emerges. The adoption of MRS as a routine diagnostic and patient management tool in clinical medicine has, however, been quite slow when compared to the rapid acceptance of magnetic resonance imaging (MRI) several years ago. To understand this one must acknowl