Towards accurate quantification of metabolites and macromolecules in HR-MAS spectra of brain tumor biopsies using LCModel
Opstad K, Byrnes T, Loosemore A, Bell B, Griffiths J, Howe F
St. George's, University of London
HR-MAS 1H MRS of whole biopsies provides detailed biochemical profiles that can be related to the lower resolution spectra obtained in vivo. Nevertheless there is still significant overlap of many resonance peaks and contributions from broad macromolecule resonances that impede accurate quantification. We have determined a first set of metabolite and macromolecule resonances needed for an LCModel quantification of brain tumor biopsies. Our data suggests that when fitting resonances of coupled spins systems in high-resolution spectra interactions between metabolites and the macromolecular environment of the biopsy cause small peak shifts not found in solution spectra, which must be accounted for.