title: Comparison of cerebral occipital gray and parietal white matter metabolite differences using PRESS and STEAM at different echo times.
abstract: BACKGROUND
  Reports regarding the differences in metabolite ratios with different echo times (TEs) at various brain regions are rare. The purpose of this study is to investigate in Chinese the cerebral metabolite ratios in gray matter (GM) and white matter (WM) using both STEAM and PRESS techniques at TEs of 30 ms and 136 ms, respectively.
  
  
  METHODS
  Using GE Signa 1.5 T Scanner with STEAM and PRESS sequences, automated single voxel localized proton magnetic resonance spectroscopy (1H-MRS) were applied to identify the metabolite ratio differences in cerebral parietal white and occipital gray matter of healthy volunteers.
  
  
  RESULTS
  Metabolite ratios between GM and WM were significantly different in N-acetyl aspartate/creatine (Cr), choline/Cr and myo-inositol/Cr. There were also significant differences in metabolite ratios when different echo times were applied.
  
  
  CONCLUSIONS
  Reliable metabolite ratios at different brain regions can be obtained using automated data acquisition and spectral processing in single voxel localized 1H-MRS. This technique may remove user-dependent bias and provide more efficient and consistent ways to analyze the spectral data. However, one must be careful in interpreting spectroscopic data based on different regions and acquisition parameters.
authors.affiliation: First Department of Diagnostic Radiology, Chang Gung Memorial Hospital, Taipei, College of Medicine and School of Medical Technology, Chang Gung University Taoyuan.
authors.forename: Y L
authors.initials: YL
authors.lastname: Wan
authors.forename: C
authors.initials: C
authors.lastname: Chang
authors.forename: S H
authors.initials: SH
authors.lastname: Ng
authors.forename: Y Y
authors.initials: YY
authors.lastname: Wai
authors.forename: H F
authors.initials: HF
authors.lastname: Wong
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008875:Middle Aged; D013997:Time Factors