Scalable Hyperpolarized MRI Enabled by Ace-SABRE of [1-13C]Pyruvate.

Hyperpolarized (HP) MRI using [1-13C]pyruvate is emerging as a promising molecular imaging approach. Among hyperpolarization methods, Signal Amplification By Reversible Exchange (SABRE) is attractive because SABRE polarizes the substrates directly in room-temperature solutions avoiding complex hardware. Most SABRE experiments have historically been performed in methanol, a relatively toxic and difficult-to-remove solvent. Here we demonstrate the use of a 80/20 acetone/water (A/W) solvent system (Ace-SABRE) to provide hyperpolarized [1-13C]pyruvate with up to 17% polarization, then implement a solvent processing protocol to achieve injectable solutions retaining 74% of the initial polarization, and lastly we demonstrate HP in vivo spectroscopy and imaging using the Ace-SABRE platform to showcase metabolic tracking in a hepatocellular carcinoma (HCC) tumor as well as HP-MRI, both in direct comparison to dissolution dynamic nuclear polarization (d-DNP) experiments. The Ace-SABRE technique promises faster adoption of SABRE hyperpolarization in biological experiments, overall lowering the barriers to entry for HP-NMR and HP-MRI.