Figure 1.

Representative dynamic ¹³C MRS spectra measured in a C57BL/6 mouse (left) and a NMRI mouse (right) head following the injection of hyperpolarized [1-¹³C]lactate. Along with the substrate resonance at 183 ppm, the three expected metabolites were detected: [1-¹³C]pyruvate at 171 ppm, [¹³C]bicarbonate at 161 ppm, and [1-¹³C]alanine at 176 ppm (overlapping with an impurity peak). The delay between each acquisition was set to 3 s, starting 2 s after the beginning of the injection. A sum of spectra 2–26 is shown at the top.