Imaging oxygen tension in liver and spleen by 19F NMR

Abstract

¹⁹F NMR imaging of the perfluorocarbon emulsion Fluosol^TM has been used to study regional variations in oxygen tension in rat liver and spleen. We have used the linear dependence of spin lattice relaxation rate (1/T₁) on the partial oxygen pressure (pO₂) of Fluosol^TM to determine the oxygen tension in the reticuloendothelial system (RES) of the liver and spleen of male Sprague‐Dawley rats which have serial infusions of Fluosol^TM. Oxygen tension maps have been computed from ¹⁹F NMR images using a calibration obtained for Fluosol^TMin vitro at 37.5°C. The spatial resolution of the pO₂ maps computed using this technique is 1.2 × 1.2 mm in 3‐mm thick slices. Calculations from in vivo pO₂ maps indicate an average change in the median pO₂ of the RES from 118 to 80 mmHg for (n = 7) rats breathing 95% O₂ and 5% CO₂ (carbogen) and air, respectively.