The new technology uses a hyperpolarized form of the noble gases helium and xenon, which is extremely soluble in lipids. Conventional magnetic resonance imaging relies on the strong signal from water protons, abundant in living organisms, but which often produces low contrast images. This is particularly problematic in imaging the lungs and lipid parts of nerves and the brain - most significantly the perfusion of the white matter of the brain which is currently inaccessible to any form of MRI. Non-hyperpolarized xenon is only moderately detectable by MRI, and virtually undetectable at the concentrations attainable in living organisms. When xenon is hyperpolarized, however, its detectability is enhanced by about a hundred thousand times - producing extremely high resolution MRI images.

Professors Bennett Goldberg, associate professor of physics and of electric and computer engineering and Selim Unlu, assistant professor of electrical and computer engineering, together with Dr. Mitchell Albert of Brigham and Woman's Hospital, will develop the stable, high-power, diode-laser driven optical pumping apparatus necessary to produce the large quantities of hyperpolarized xenon which are key to the success of the system.

The multi-disciplinary research team, combining expertise ranging from optical engineering and atomic physics to MRI technology and physiology, is funded by the National Science Foundation.

Photo: An intensity/spectral map (left) of a typical commercial diode-laser shows large wavelength variations. It clearly illustrates the engineering challenge involved in producing the very high power, but narrow linewidth laser needed to produce the noble gases utilized in this process; an image of lungs (right) using the new MRI technique.