1H-13C MR spectroscopic imaging of dynamic glucose metabolism in rat brain in vivo

Motivation: Indirect 1H-13C MRSI can uniquely provide a wealth of metabolic information, provided that technical challenges are overcome. Goal(s): To develop 1H-13C MRSI methods for quantitative rate mapping of glucose metabolism on rat brain in vivo. Approach: 1H-13C MRSI was implemented with octagonal volume pre-selection, 2D phase encoding, 13C editing and 13C decoupling. Results: Dynamic mapping of 13C transfer from U-13C6-glucose to 4-13C-Glu, 4-13C-Gln and 3-13C-Lac was achieved at 15.6 μL spatial and 12 min temporal resolution. At isotopic steady-state the spatial resolution could be increased to 8 μL (in 33 min). Impact: 1H-13C-MRSI is characterized by unique spectral features not offered by other dynamic metabolic imaging methods (HP, DMI). The ability to separate cerebral Glu from Gln and detect total and 13C-labeled pools makes 1H-13C-MRSI an unique and valuable metabolic imaging method.