In vivo 19F NMR imaging.

In vitro and in vivo 19F spectra and images were obtained using various clinically safe fluorinated compounds. Standard and chemical shift images were acquired in solutions of fluorinated anesthetics with the chemical shift images clearly separating signals arising from a mixture of halothane and methoxyflurane. The 19F images of halothane in rats were unsuccessful at anesthetic concentration. In vivo 19F nuclear magnetic resonance (NMR) images were acquired at 57.9 MHz in rats receiving chronic injections of 14% perfluorodecalin, 6% perfluorotripropylamine (Fluosol-DA). The liver accumulates Fluosol-DA in the reticuloendothelial cells to concentrations that allow images to be obtained in less than 30 min. Image intensity from the perfluorochemicals reflects reticuloendothelial cell activity and thus is a functional image. Conventional proton NMR images at corresponding levels confirmed that the 19F signal arose from the liver and not muscle or fat. The 19F NMR images of the large bowel and stomach in rats were obtained by filling the lumen with concentrated Fluosol-DA. High contrast anatomical images showing gross structure of the gastrointestinal tract were acquired in as little as 12 min. These data suggest that 19F NMR may have a potential role in clinical imaging.