In vivo 1H MRS and in vitro multinuclear MR study of human brain tumors.

Localized in vivo 1H MR spectra of four patients with brain tumors and in vitro multinuclear (1H, 13C and 31P) MR characterization of water soluble and lipid components of the same tumors after surgical removal are reported herein. The in vivo spectra of the neoplastic regions of all patients showed N-Acetyl-Aspartate/Choline (NAA/Cho), Choline/Creatine (Cho/Cr) and N-Acetyl-Aspartate/Creatine (NAA/Cr) metabolite ratios markedly different from those of the controlateral healthy tissue. In vitro 1H MR measurements allowed for the identification of a much larger number of metabolites than those measured in vivo. Indeed, well resolved 1H, 13C and 31P MR spectra were obtained for water soluble and lipid components in all cases. Our data confirm that some metabolites observed in vitro could be specific markers of brain tumors.