First hyperpolarized [2

We developed methods for the preparation of hyperpolarized (HP) sterile [2-(13)C]pyruvate to test its feasibility in first-ever human NMR studies following FDA-IND & IRB approval. Spectral results using this MR stable-isotope imaging approach demonstrated the feasibility of investigating human cerebral energy metabolism by measuring the dynamic conversion of HP [2-(13)C]pyruvate to [2-(13)C]lactate and [5-(13)C]glutamate in the brain of four healthy volunteers. Metabolite kinetics, signal-to-noise (SNR) and area-undercurve (AUC) ratios, and calculated [2-(13)C]pyruvate to [2-(13)C]lactate conversion rates (k(PL)) were measured and showed similar but not identical inter-subject values. The k(PL) measurements were equivalent with prior human HP [1-(13)C]pyruvate measurements.