Since its first demonstration as an imaging agent in MRI nearly a decade ago, the promise of hyperpolarized xenon has captured the attention of the research community. It can be introduced into a subject non-invasively by breathing, and has a well-understood short-term biological effect. Relative to hyperpolarized helium, its advantages include its natural abundance and low cost. Both hyperpolarized xenon and helium have demonstrated utility in lung imaging, and quantifying lung disease. In contrast to helium, however, hyperpolarized xenon has a high solubility in fluids and tissues and a characteristic chemical shift, revealing its microscopic environment in dissolved-phase imaging. Consequently, the time dependence of its transport and absorption offer prospects for functional imaging of perfusion. Using NIH R21 and R15 funds, the UNH group demonstrated a new type of xenon polarizer that flows the gas mixture at relatively high velocity and low pressure along a direction opposite to the laser beam. This polarizer demonstrated polarization of over 20% for a production rate of over four liters per hour. The figure-of-merit (polarization times production rate) of this polarizer presently exceeds all other polarizer technologies by an order of magnitude. The technology routinely used to accumulate hyperpolarized xenon, freezing in a liquid-nitrogen bath, is not well suited to accumulating multi-liter quantities. We request STTR funding to develop and test a novel, scalable approach to accumulating unlimited quantities of hyperpolarized xenon. This new method of accumulating the hyperpolarized gas will extend the capacity of our world-leading hyperpolarized xenon production apparatus. This development helps to convert this laboratory installation to a practical hospital based device. Hyperpolarized gas has already demonstrated utility in diagnosing and quantifying lung disease. We present technological, physiological, and economic arguments that hyperpolarized xenon can and perhaps will surpass gadolinium as the contrast agent of choice in a broad spectrum of diagnostic imaging protocols.
| Hersman, F William; Ruset, Iulian C; Ketel, Stephen et al. (2008) Large production system for hyperpolarized 129Xe for human lung imaging studies. Acad Radiol 15:683-92 |
| Patz, Samuel; Hersman, F William; Muradian, Iga et al. (2007) Hyperpolarized (129)Xe MRI: a viable functional lung imaging modality? Eur J Radiol 64:335-44 |
