XeNA: an automated 'open-source' (129)Xe hyperpolarizer for clinical use

Area of Science:

• Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI)
• Hyperpolarized Gas Physics
• Medical Engineering

Background:

• Nuclear spin polarization is crucial for enhancing NMR/MRI sensitivity.
• Existing hyperpolarization methods can be complex and expensive.
• Developing accessible and efficient hyperpolarization techniques is vital for broader clinical adoption.

Purpose of the Study:

• To report the construction and capabilities of an open-source, large-scale (129)Xe hyperpolarizer.
• To detail the engineering design for cost-effectiveness and ease of installation in research and clinical settings.
• To facilitate the adaptation and advancement of hyperpolarized gas applications in biomedicine.

Main Methods:

• Construction of an automated (129)Xe hyperpolarizer using off-the-shelf components.
• Operation in a xenon-rich regime (up to 1800 Torr Xe) in stopped-flow or batch mode.
• Spin-exchange optical pumping with high laser power (~200W) to achieve near-unity Rb electron spin polarization.

Main Results:

• Achieved in-cell (129)Xe nuclear spin polarization of ~30%-90% at high Xe loadings.
• Measured polarization build-up time of ~8.5 min and T1 relaxation of ~1.9 h.
• Maintained polarization during gas transfer, with ultra-long relaxation times (up to 6h) observed in Tedlar bags.

Conclusions:

• The developed hyperpolarizer is cost-effective (<$125,000) and suitable for clinical and research use.
• High polarization is maintained during gas transfer, enabling remote use.
• FDA IND approval for a clinical study signifies potential for in vivo biomedical applications.