Biological magnetic resonance imaging using laser-polarized super(129)Xe

• Published in: Nature (London) 1994-01, Vol.370 (6486), p.199-201
• Main Authors: Albert, MS, Cates, G D, Driehuys, B, Happer, W, Saam, B, Springer, CS Jr, Wishnia, A
• Format: Article
• Language: English
• ISSN: 0028-0836

As currently implemented, magnetic resonance imaging (MRI) relies on the protons of water molecules in tissue to provide the NMR signal. Protons are, however, notoriously difficult to image in some biological environments of interest, notably the lungs and lipid bilayer membranes such as those in the brain. Here we show that super(129)Xe gas can be used for high-resolution MRI when the nuclear-spin polarization of the atoms is increased by laser optical pumping and spin exchange. This process produces hyperpolarized super(129)Xe, in which the magnetization is enhanced by a factor of about 10 super(5). By introducing hyperpolarized super(129)Xe into mouse lungs we have obtained images of the lung gas space with a speed and a resolution better than those available from proton MRI or emission tomography. As xenon (a safe general anaesthetic) is rapidly and safely transferred from the lungs to blood and thence to other tissues, where it is concentrated in lipid and protein components, images of the circulatory system, the brain and other viral organs can also be obtained. Because the magnetic behaviour of super(129)Xe is very sensitive to its environment, and is different from that of super(1)H sub(2)O, MRI using hyperpolarized super(129)Xe should involve distinct and sensitive mechanisms for tissue contrast.