title: Quantitative brain proton MR spectroscopy based on measurement of the relaxation time T1 of water.
abstract: OBJECTIVE
  To provide a straightforward method for metabolite quantitation in the brain. Tissue water concentration can be determined in a voxel by measuring T(1) and it may provide an internal reference for the calculation of the metabolite concentrations.
  
  
  METHODS
  Water-suppressed stimulated echo acquisition mode spectra were obtained at 1.5T, and the tissue water content was calculated from T(1).
  
  
  RESULTS
  The calculated water content values demonstrated very good agreement with literature data. Metabolite concentrations (mmol/liter) in the gray and white matter: N-acetyl-aspartate = 14.02 +/- 1.93, creatine = 9.98 +/- 1.03, and choline = 1.14 +/- 0.24; N-acetyl-aspartate = 11.08 +/- 2.24, creatine = 7.83 +/- 0.66, and choline = 2.05 +/- 0.38, respectively.
  
  
  CONCLUSIONS
  The water content calculated from T(1) can yield an internal reference in MR spectroscopy, and the accurate measurement of metabolite concentrations is feasible. The proposed method is simple and can readily be applied in any MR center without the need for complicated corrections or calibration procedures.
authors.affiliation: Institute of Diagnostic Radiology and Radiation Oncology, University of Kaposvár, 40 Guba Sándor Street, Kaposvár, Hungary. bajzik.gabor@sic.hu
authors.forename: Gábor
authors.initials: G
authors.lastname: Bajzik
authors.forename: Tibor
authors.initials: T
authors.lastname: Auer
authors.forename: Péter
authors.initials: P
authors.lastname: Bogner
authors.forename: Miklós
authors.initials: M
authors.lastname: Aradi
authors.forename: Gyula
authors.initials: G
authors.lastname: Kotek
authors.forename: Imre
authors.initials: I
authors.lastname: Repa
authors.forename: Tamas
authors.initials: T
authors.lastname: Doczi
authors.forename: Attila
authors.initials: A
authors.lastname: Schwarcz
mesh_terms: D000328:Adult; D001923:Brain Chemistry; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D014764:Viral Proteins; D014867:Water / Q000032:analysis
chemical_list: D014764:Viral Proteins; C079287:scaffold protein, Herpes simplex virus-1; D014867:Water