Hyperpolarized 13C Magnetic Resonance Imaging of Fumarate Metabolism by Parahydrogen‐induced Polarization: A Proof‐of‐Concept in Vivo Study

Hyperpolarized [1-C-13]fumarate is a promising magnetic resonance imaging (MRI) biomarker for cellular necrosis, which plays an important role in various disease and cancerous pathological processes. To demonstrate the feasibility of MRI of [1-C-13]fumarate metabolism using parahydrogen-induced polarization (PHIP), a low-cost alternative to dissolution dynamic nuclear polarization (dDNP), a cost-effective and high-yield synthetic pathway of hydrogenation precursor [1-C-13]acetylenedicarboxylate (ADC) was developed. The trans-selectivity of the hydrogenation reaction of ADC using a ruthenium-based catalyst was elucidated employing density functional theory (DFT) simulations. A simple PHIP set-up was used to generate hyperpolarized [1-C-13]fumarate at sufficient C-13 polarization for ex vivo detection of hyperpolarized C-13 malate metabolized from fumarate in murine liver tissue homogenates, and in vivo C-13 MR spectroscopy and imaging in a murine model of acetaminophen-induced hepatitis.