High Sensitivity 19F MRI Allows Dynamic Biodistribution Study & Oxygen Tension Mapping at Pharmaceutical Doses of a PFOB Emulsion in the Mouse Reticuloendothelial System

Cline Giraudeau¹, Boucif Djema¹, Sidi Mohamed Ould Ahmed Ghaly¹, Philippe Robert², Marc Port², Caroline Robic², Denis Le Bihan¹, Franck Lethimonnier¹, Julien Valette¹

PFOB emulsions are promising tracers for quantitative ¹⁹F MRI of the reticuloendothelial system (RES). Using a PFOB-dedicated multi spin echo (MSE) sequence, we show that kinetics of accumulation of PFOB nanoparticles in the RES can be quantified and that stealth of emulsions including different quantities of polyethylene glycol can be assessed. Moreover, oxygen pressure mapping can be performed in the RES after one single injection of emulsion. These results are promising for monitoring of the RES status in vivo.