MRI for hyperpolarized gases
Princeton, University of Virginia, University of New Hampshire
Result of NP research:
Polarized gas targets/spin filters for electron scattering experiments at MIT-Bates, Jefferson Lab, and Saskachewan Lab, and cold-neutron parity violation measurements at LANSCE.
Application currently being supported by:
Impact/benefit to spin-off field:
Static & dynamic imaging of lungs, heart, and possibly the brain, possible imaging of astronauts
'Hyperpolarized gas imaging
', a new type of magnetic resonance imaging (MRI), is an application arising from DOE-supported fundamental research. This is a technique in which a noble gas such as He-3 or Xe-129 is polarized using lasers, and is subsequently inhaled by a patient. A conventional whole-body scanner, with only minor modifications, can then be used to make images of the gas space of the lungs with unprecedented resolution. Hyperpolarized gas imaging is particularly important because, up until now, there were no techniques for producing high resolution images of the gas space of the lungs. Xe also dissolves into the blood and is transported throughout the body, raising expectations that detailed images of the brain or other organs might also be possible.
Hyperpolarized gas imaging (HGI) is an excellent example of how fundamental research can provide valuable and unanticipated benefits to society. The laser technique with which the noble gas is polarized was first demonstrated in the 1960's. It has evolved over 30 years of R&D in response to the availability of more advanced laser technology and the need to produce large volumes (~2 liters) of highly polarized targets for use at DOE Nuclear Physics labs such as Thomas Jefferson National Accelerator Facility (TJNAF). These advances led nuclear physicists in the 1990s to provide the first images of human lungs using He-3. Commercial applications of such techniques are currently undergoing formal FDA trials. The technique provides the first detailed images of lung air volume. It appears quite promising for the detection and management of pulmonary diseases like asthma, emphysema, and other pulmonary diseases, and will have future use for the study of other organs including the brain.
First image: using hyperpolarized 3He MRI to study the effect of asthma on human lungs. (University of Virginia)
Second image: first human lung images using 129Xenon hyperpolarized gas (1997). Normal proton image (left); 129Xe image of the lungs (right); composite image at the center. (University of Virginia)