Keynote talk: Hyperpolarized-gas MRI of the lung -- Can research potential translate to clinical application?
The exceptionally high magnetic-resonance signal provided by hyperpolarized noble gases, such as helium-3 and xenon-129, permits direct, high-resolution MRI of the airspaces of the lung. Combining this high signal with the inherent flexibility of MRI has resulted in an arsenal of techniques that offer a wealth of regional information on the functional status and structure of the healthy and diseased lung. No other medical-imaging modality can provide comparable information about the lung, which is of particular relevance considering the growing need to address the global impact of pulmonary diseases, such as asthma and chronic obstructive pulmonary disease, on health and quality of life.
Despite this impressive and unique potential, which has been amply demonstrated through a wide range of research studies in animals and humans, hyperpolarized-gas MRI has yet to translate to a clinical imaging tool. Although an outside observer of the field may conclude that lack of translation means lack of sufficient added value to the evaluation of pulmonary diseases, the true reason is rooted in practical and technical issues, not ultimate potential. On the practical side, commercial and patent issues have blocked widespread dissemination of hyperpolarized-gas technology since the late 1990s. On the technical side, improved image-analysis approaches are needed to distill imaging results into robust metrics for diagnostic or therapeutic decision making. Recent developments on both the commercial and technical fronts provide optimism that it will soon be possible to move hyperpolarized-gas MRI of the lung beyond a handful of academic centers, allowing the true value of this exciting technology for the treatment and monitoring of pulmonary diseases to be assessed.
John P. Mugler, III, Ph.D., is a Professor of Radiology & Medical Imaging, and Professor of Biomedical Engineering, at the University of Virginia. He has been an active researcher in human applications of MRI for 25 years, focusing on the development and application of techniques for imaging the lung using hyperpolarized noble gases, and on the development and optimization of pulse sequences for three-dimensional anatomical imaging. As Co-Director of the Center for In-Vivo Hyperpolarized Gas MR Imaging at the University of Virginia, he is the lead pulse-sequence developer for a team of researchers who have made pioneering contributions to hyperpolarized-gas imaging of the lung, including the first hyperpolarized-xenon images of the human lung in 1996.