>106 x enhancement of 13C-enriched pyruvate via in situ hyperpolarization in an ultra-low field MRI scanner

Motivation: Altered cell metabolism is one of the hallmarks of cancer. 13C metabolic MRI has shown promise in delineating, grading and monitoring treatment response in cancer but 13C MRI has been dominated by dynamic nuclear polarization technology that is expensive and slow. Goal(s): A flexible and accessible alternative is necessary to enable the adoption of 13C MRI in standard of care cancer diagnosis and treatment. Approach: Spin-lock induced crossing signal amplification by reversible exchange (SLIC SABRE), a quick and versatile hyperpolarization technique, was used to polarize [1-13C] pyruvate in situ at 6.5mT. Results: Here we show hyperpolarized [1-13C] pyruvate enhanced by factors >106 times. Impact: These results are the first demonstration of 13C hyperpolarization generated and measured in situ at 6.5mT and showcase the flexibility and utility of SLIC SABRE as a hyperpolarization method to drive widespread adoption of 13C metabolic MRI in the clinic.