title: Validation of glutathione quantitation from STEAM spectra against edited 1H NMR spectroscopy at 4T: application to schizophrenia.
abstract: OBJECTIVE
  Quantitation of glutathione (GSH) in the human brain in vivo using short echo time 1H NMR spectroscopy is challenging because GSH resonances are not easily resolved. The main objective of this study was to validate such quantitation in a clinically relevant population using the resolved GSH resonances provided by edited spectroscopy. A secondary objective was to compare several of the neurochemical concentrations quantified along with GSH using LCModel analysis of short echo time spectra in schizophrenia versus control.
  
  
  METHODS
  GSH was quantified at 4T from short echo STEAM spectra and MEGA-PRESS edited spectra from identical volumes of interest (anterior cingulate) in ten volunteers. Neurochemical profiles were quantified in nine controls and 13 medicated schizophrenic patients.
  
  
  RESULTS
  GSH concentrations as quantified using STEAM, 1.6 +/- 0.4 micromol/g (mean +/- SD, n = 10), were within error of those quantified using edited spectra, 1.4 +/- 0.4 micromol/g, and were not different (p = 0.4). None of the neurochemical measurements reached sufficient statistical power to detect differences smaller than 10% in schizophrenia versus control. As such, no differences were observed.
  
  
  CONCLUSIONS
  Human brain GSH concentrations can be quantified in a clinical setting using short-echo time STEAM spectra at 4T.
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of MN, Minneapolis, MN 55455, USA. melissa@cmrr.umn.edu
authors.forename: Melissa
authors.initials: M
authors.lastname: Terpstra
authors.forename: T J
authors.initials: TJ
authors.lastname: Vaughan
authors.forename: Kamil
authors.initials: K
authors.lastname: Ugurbil
authors.forename: Kelvin O
authors.initials: KO
authors.lastname: Lim
authors.forename: S Charles
authors.initials: SC
authors.lastname: Schulz
authors.forename: Rolf
authors.initials: R
authors.lastname: Gruetter
mesh_terms: D000328:Adult; D000465:Algorithms; D015415:Biomarkers / Q000032:analysis; D005260:Female; D005978:Glutathione / Q000032:analysis*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D011522:Protons; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis* / Q000378:metabolism*; D012680:Sensitivity and Specificity; D016037:Single-Blind Method
chemical_list: D015415:Biomarkers; D011522:Protons; D005978:Glutathione