Hyperpolarized ¹²⁹Xe MRI using dissolution dNP on a commercial polarizer: from solid-state optimization to in vivo lung imaging

Hyperpolarized ¹²⁹Xe gas is a powerful diagnostic tool in pulmonary MRI, uniquely enabling imaging of ventilation and gas exchange through its dissolved-phase signal. While xenon is conventionally hyperpolarized using spin-exchange optical pumping (SEOP), an alternative approach based on dynamic nuclear polarization (DNP) followed by sublimation has emerged. However, xenon DNP has so far been restricted to custom-built hardware and primarily explored for solid-state physics applications. In this work, we establish optimized conditions for solid-state polarization of xenon using a commercial DNP polarizer. The resulting robust and reproducible protocol enables in vivo imaging in porcine lungs, providing sufficient signal to extract biologically relevant information comparable to that obtained with SEOP. This work bridges a critical gap in xenon DNP, advancing it from proof-of-principle demonstrations on specialized systems to implementation on standardized instrumentation suitable for in vivo applications.