Perfluorocarbon emulsions as intravenous delivery media for hyperpolarizedxenon

The use of perfluorooctyl bromide (PFOB) emulsions as delivery media for hy perpolarized xenon has been investigated. Emulsion droplet size was control led by varying the content of egg yolk phospholipid (EYP), which served as an emulsifier. Hyperpolarized Xe-129 nuclear magnetic resonance (NMR) spect ra of the dissolved gas were obtained. The NMR spectra were found to be cor related strongly with the emulsion droplet size distribution. The NMR line width is determined by xenon exchange between the PFOB droplets and the aqu eous environment. Our findings show that, in a 1.5-Tesla field, relatively narrow Xe-129 NMR spectra are obtained for droplet sizes larger than 5 mu m . Preliminary results on animal models show that PFOB emulsions have potent ial as hyperpolarized Xe-129 carriers for in vivo magnetic resonance applic ations. Magn Reson Med 41:442-449, 1999. (C) 1999 Wiley-Liss, Inc.