Alexander
  Gussew1, Marko Erdtel1,2, Reinhard Rzanny1,
  Juergen R. Reichenbach1
1Medical Physics Group, Department of
  Diagnostic and Interventional Radiology, Jena University Hospital, Jena,
  Germany; 2University of Applied Sciences Jena, Jena, Germany
This
  work describes in vitro and in vivo validation of absolute
  quantitation of 1H-MRS brain data with respect to heterogeneous
  tissue distributions within the MRS-volume. NAA concentrations were estimated
  from metabolite and water spectra obtained from MRS-voxels containing
  different metabolite and water
  concentrations and were compared with nominally adjusted values. The maximal
  error was 4% compared to 41%, if the tissue heterogeneity was neglected. Inter-individual
  distributions of NAA-, Cr- and tCho-concentrations obtained in insular cortex
  of volunteers had twice less scatter when taking into account the
  heterogeneous tissue composition in the voxel.
Keywords