Magnetic resonance spectroscopy in traumatic brain injury

Magnetic resonance spectroscopy (MRS) offers a unique non-invasive approach for assessing the metabolic status of the brain in vivo and is particularl y suited to studying traumatic brain injury (TBI). In particular, MRS provi des a noninvasive means for quantifying such neurochemicals as N-acetylaspa rtate (NAA, creatine, phosphocreatine, choline) lactate, myo-inositol, glut amine, glutamate, adenosine triphosphate (ATP), and inorganic phosphate in humans following TBI and in animal models. Many of these chemicals have bee n shown to be perturbed following TBI. NAA, a marker of neuronal integrity, has been shown to be reduced following TBI, reflecting diffuse axonal inju ry or metabolic depression, and concentrations of NAA predict cognitive out come. Elevation of choline-containing compounds indicates membrane breakdow n or inflammation or both. MRS can also detect alterations in high energy p hosphates reflecting the energetic abnormalities seen after TBI. Accordingl y, MRS may be useful to monitor cellular response to therapeutic interventi ons in TBI.