Fast PHIP-based hyperpolarization of 13C 𝛼-ketoacids using POLARIS: high polarization, reproducibility, and in vivo results

Motivation: To provide a commercially available hyperpolarizer producing hyperpolarized agents rapidly and reliably, to enable large scale metabolic imaging studies. Goal(s): To assess the reproducibility and polarization levels of the 13C-labeled 𝛼-ketoacids pyruvate and 𝛼-ketoglutarate achieved by POLARIS, a commercially available preclinical PHIP-based hyperpolarizer. Approach: POLARIS produced injectable doses of hyperpolarized 13C-labeled pyruvate and 𝛼-ketoglutarate in 90 seconds. Polarization and reproducibility were assessed, and in vivo hyperpolarized imaging data acquired. Results: Polarization of >30% for pyruvate and >25% for 𝛼-ketoglutarate were achieved reproducibly. In vivo images demonstrate biodistribution of 𝛼-ketoglutarate and metabolism of pyruvate in the healthy mouse brain. Impact: POLARIS enables rapid, reproducible and high polarization of 13C-labeled 𝛼-ketoacids with an easy-to-use, highly automated workflow. This breakthrough enables fast, reproducible results, paving the way for extensive, consistent studies that will significantly advance the field of hyperpolarized MRI.