Detection of acute radiation damage to the spleen in mice by using fluorine-19 MR imaging

Previous work in our laboratory has shown that an IV-administered emulsion of perfluorooctylbromide, an agent known to localize in functioning macrophages in the reticuloendothelial system, can be detected in the liver and spleen by using fluorine-19 (19F) MR imaging. In mice that have received a single radiation dose of 1300 rad (13 Gy) (250 kVp) to the abdomen, relatively diminished uptake of perfluorooctylbromide emulsion in the spleen is seen as few as 12 days after irradiation when using 19F MR. When a GE NMR CSI 2-T spectroscopy/imaging system was used, 19F MR images were obtained in 2-16 min, and the postirradiation changes in the spleen were shown. This approach is the first that allows detection of acute postirradiation damage in the spleen in as few as 12 days and potentially allows assessment of macrophage dysfunction in vivo.