Liposomes are spherical bilayers which spontaneously form when water is added to a dried lipid mixture. Much progress has been made in the use of liposomes as vehicles for the delivery of gamma imaging agents. These radiolabeled liposomes have a wide variety of potential diagnostic uses including the detection of sites of infection, inflammation, gastrointestinal bleeding, tumor, cardiac blood pool imaging and lymphoscintigraphy. The ability to modify the surface of the liposomes permits the customization of liposome formulations for each particular diagnostic use.