An oil-in-water nanoemulsion composition for MRI, comprising an aqueous phase, a lipid phase as nanodroplets comprising an oil and magnetic particles based on an iron compound and covered with one or several C8-C22 fatty acids, and a mixture of surfactants at the interface between the aqueous and lipid phases, the mixture of surfactants comprising at least one amphiphilic lipid and at least one amphiphilic targeting ligand.
