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

Localized in vivo 1 H MR spectra of four patients with brain tumors and in vitro multinuclear ( 1 H, 13 C and 31 P) 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 1 H MR measurements allowed for the identification of a much larger number of metabolites than those measured in vivo. Indeed, well resolved 1 H, 13 C and 31 P MR spectra were obtained for water soluble and lipid components in all cases. Our data confirm that some metabolites obsered in vitro could be specific markers of brain tumors.