title: Quantitative in vivo 1H spectroscopic imaging of metabolites in the early postnatal mouse brain at 17.6 T.
abstract: OBJECTIVE
  Early postnatal brain maturation is closely connected to local changes of metabolite levels. Spatially resolved in vivo (1)H NMR spectroscopic imaging is applied to follow absolute changes of brain metabolites in early postnatal mouse brain.
  
  
  METHODS
  A short echo time semi LASER (localization by adiabatic selective refocusing) chemical shift imaging (CSI) sequence incorporating weighted k-space averaging was implemented at high magnetic field (17.6 T). In vivo measurements were carried out on postnatal days 5, 8, 12, 16, and 20. In vivo relaxation times T (1) and T (2) were measured using variable repetition times or a CPMG sequence, respectively, combined with LASER single voxel localization.
  
  
  RESULTS
  Spectra were obtained with a spatial resolution of (1 x 1) mm(2) in a 1.5 mm slice as early as postnatal day 5. Maturational changes of absolute metabolite concentrations of major metabolites were calculated in four different brain regions. A significant increase of N-acetylaspartate (NAA), total creatine (tCr), and glutamate/glutamine (Glx) concentration was paralleled by a decrease of taurine (Tau) concentration with age (P < 0.05). Differences between brain regions were found for NAA, tCr, and Tau (P < 0.05). Furthermore, in vivo T (1) and T (2) of the four major brain metabolites in adult mice are reported.
  
  
  CONCLUSIONS
  The implemented semi LASER CSI sequence allows following regional changes of metabolite levels. It is suitable for investigation of local differences in brain metabolism and development.
authors.affiliation: Department of Experimental Physics 5, University of Würzburg, Würzburg, Germany. kweiss@biomed.ee.ethz.ch
authors.forename: Kilian
authors.initials: K
authors.lastname: Weiss
authors.forename: Gerd
authors.initials: G
authors.lastname: Melkus
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.forename: Cornelius
authors.initials: C
authors.lastname: Faber
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000254:growth & development* / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D018377:Neurotransmitter Agents / Q000032:analysis*; D011522:Protons; D014018:Tissue Distribution
chemical_list: D018377:Neurotransmitter Agents; D011522:Protons