Physical Basis of Magnetic Resonance Spectroscopy and its Application to Central Nervous System Diseases

Magnetic Resonance Spectroscopy is based on the chemical shift property of the atom nuclei when a magnetic field is applied. This technique offers invaluable information about living tissues with special contribution to the diagnosis and prognosis of the central nervous system diseases. Concentration of several metabolites can be assessed in a reproducible manner by means of modern clinical scanners. N-acetyl-aspartate is regarded as a neuronal marker and its levels reflect the neuronal density with significant decreases in degenerative disease such as Alzheimer's disease. Choline-compounds reflect the cell's membrane turnover and degradation. Myo-inositol has emerged as a glial marker with increases in degenerative diseases. The major usefulness of MRS has been reported in brain tumors, degenerative disorders, myelination defects and encephalopathies. In this review we report the physical basis and the contribution of MR spectroscopy to the diagnosis and prognosis of several diseases of the Central Nervous System.