High-Pressure Clinical-Scale 87% Parahydrogen Generator

Area of Science:

• Hyperpolarized contrast agents
• Magnetic Resonance Imaging (MRI)
• Quantum chemistry

Background:

• Parahydrogen-induced polarization (PHIP) and Signal Amplification by Reversible Exchange (SABRE) enhance MRI sensitivity.
• Existing parahydrogen generators have limitations in enrichment, pressure, or cost.
• Clinical translation of PHIP/SABRE requires scalable and efficient parahydrogen production.

Purpose of the Study:

• To present an automated, high-pressure parahydrogen generator (ParaSun) for clinical-scale PHIP and SABRE.
• To achieve high parahydrogen enrichment using a cryo-cooler and efficient catalyst.
• To bridge the gap between low-enrichment and high-cost, high-enrichment systems.

Main Methods:

• Utilized a vacuum-pumped Sunpower cryo-cooler for cooling to ~40 K.
• Employed an FeO(OH) catalyst for ortho- to para-state conversion.
• Integrated a mass-flow controller for controlled H2 gas flow at 150 sccm and up to 490 PSI.

Main Results:

• Achieved up to ~87% parahydrogen enrichment.
• Reached target temperature in under 1 hour.
• Operated at a maximum outlet pressure of ~490 PSI.

Conclusions:

• The ParaSun generator offers a practical solution for clinical-scale PHIP and SABRE.
• It provides a cost-effective alternative to existing high-enrichment systems.
• Enables the development of novel hyperpolarized contrast agents for biomedical imaging.