LOCALIZED PROTON MR SPECTROSCOPY OF THE BRAIN IN CHILDREN

Small-voxel (3.0-8.0 cm3), magnetic resonance (MR) imaging-guided prot on MR spectroscopy was performed in 54 patients (aged 6 days to 19 yea rs) with intracranial masses (n = 16), neurodegenerative disorders (n = 34), and other neurologic diseases (n = 4) and in 23 age-matched con trol subjects without brain disease. A combined short TE (18 msec) sti mulated-echo acquisition mode (STEAM) and long TE (135 and/or 270 msec ) spin-echo point-resolved spatially localized spectroscopy (PRESS) pr otocol, using designed radio-frequency pulses, was performed at 1.5 T. STEAM spectra revealed short T2 and/or strongly coupled metabolites; prominent resonances were obtained from N-acetyl aspartate (NAA), chol ine-containing compounds (Cho), and total creatine (tCr). Lactate was well resolved with the long TE PRESS sequence. Intracranial tumors wer e readily differentiated from cerebrospinal fluid (CSF) collections. A ll tumors showed low NAA, high Cho, and reduced tCr levels. Neurodegen erative disorders showed low or absent NAA levels and enhanced mobile lipid, glutamate and glutamine, and inositol levels, consistent with n euronal loss, gliosis, demyelination, and amino acid neurotoxicity. Pr eliminary experience indicates that proton MR spectroscopy can contrib ute in the evaluation of central nervous system abnormalities of infan ts and children.