Figure 3.

3D ²H CSI of [6,6-²H₂]glucose metabolism in A11 and S2 tumors, in normal-appearing brain tissue, and in brain tissue in tumor-free mice. A-C, Representative spectrum from a voxel within the brain of a tumor-free mouse (A), and representative spectra from voxels within the tumor and normal-appearing brain of A11 (B) and S2 (C) tumor–bearing animals injected with 2 g/kg [6,6-²H₂]glucose. Fits to the spectra are shown in color: red, water; green, glucose; blue, Glx; and purple, lactate. The tumor is outlined in yellow on the T₂-weighted ¹H image. The locations of the CSI voxels are indicated by the boxes. The spectra are the sum of six 10-minute spectra acquired from 3 × 3 × 9 mm voxels. D-F, Comparison of ²H-labeled glucose (D), Glx (E), and lactate (F) concentrations in the brains of tumor-free mice and the normal-appearing brain of mice bearing A11 and S2 tumors. G-I, Comparison of ²H-labeled glucose (G), Glx (H), and lactate (I) concentrations in A11 tumors and adjacent normal-appearing brain tissue. J-L, Comparison of ²H-labeled glucose (J), Glx (K), and lactate (L) concentrations in S2 tumors and adjacent normal-appearing brain tissue. ns, not significant; *, P < 0.05; ***, P < 0.001.