In Vivo 19F NMR Imaging

Abstract

Surgicaln vitro and in vivo ¹⁹F spectra and images were obtained using various clinically safe fluorinated compounds. Standard and chemical shift images were aquired 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 reticulendothelial 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.