Recent advances of in vivo magnetic resonance imaging with laser-polarized noble gases

The field of polarization-based magnetic resonance imaging has expanded rapidly in the past few years. Realization of this new modality of medical imaging is dependent upon the production of large quantities of noble gas. Additionally the noble gas must be delivered to the subject in controlled and efficient manner. The process of delivery must also preserve a large fraction of the polarization for the method to be effective. The authors have constructed a polarization and delivery system that is currently in use in the fringe field of a MRI magnet. This polarization system utilizes high power laser diode arrays as a practical means to delivery a high flux of polarized photons. The authors have done initial imaging studies using laser polarized xenon-129. The discussion covers the technique and optimization of the polarized noble gas production and delivery. The efficacy of the system is demonstrated in the spectroscopic and spatially resolved NMR data.