Using injectable carriers of laser‐polarized noble gases for enhancing NMR and MRI

Laser-polarized noble gases hold enormous potential for enhancing sensitivity and contrast for a variety of nuclear magnetic resonance and magnetic resonance imaging experiments. Potential biomedical applications are especially tantalizing; however, overcoming the difficulty of delivering laser-polarized noble gases to living tissues with sufficient polarization and concentration may be critical to the feasibility of many proposed in vivo studies. One suggested means of delivering laser-polarized noble gases to tissues involves the local injection of biologically compatible solutions in which high noble gas concentrations and long polarization lifetimes can be achieved. In this review, the general topic of biomedical applications of laser-polarized noble gases is introduced. Special attention is given to a description of the injection technique and its applications, along with a discussion of potential advantages and limitations. Concluding remarks discuss the future outlook for biomedical applications of laser-polarized noble gases in general, particularly in light of recent low-field magnetic resonance experiments. ©1999 John Wiley & Sons, Inc. Concepts Magn Reson 11: 203–223, 1999