IN-VIVO SINGLE VOXEL H-1 MRS OF GLIAL BRAIN-TUMORS - CORRELATION WITHTISSUE HISTOLOGY AND IN-VITRO MRS

Eighteen patients affected by glial brain tumors were examined by loca lized single voxel magnetic resonance spectroscopy (H-1 MRS). For all patients histological diagnosis was obtained after stereotactic biopsy or surgical removal of the tumor. Histological nuclear atypia, tumor cellularity, necrosis, vascular proliferation and percentage of Ki-67 positive cells in the total cell populations were evaluated. It was fo und that some of the in vivo H-1 MRS parameters were related to the hi stological features of the tumor. In particular, the Cho(i)/Cr-i metab olite ratio obtained from the neoplastic tissues paralleled the Ki-67 cell proliferation index. For some of the patients H-1 and C-13 in vit ro high resolution magnetic spectroscopy of surgical specimens was als o carried out. H-1 MRS of aqueous extracts from different biopsy speci mens of the same tumor furnished fine biochemical information on intra tumor heterogeneity. The degree of histological vascular proliferation of the tumor was correlated to the presence of cholesteryl esters in the C-13 spectrum of the lipid fraction of surgical specimens.