Effect of therapeutic dose of heparin on in vivo labeling of red blood cells with Technetium-99m for blood-pool imaging: Importance of stannous ion concentration

While convenience and economy favor the use of in vivo methods for labeling red blood cells (RBC's) with technetium-99m pertechnetate, previous reports suggested that patient medication and therapy in some cases might interfere with the RBC labeling and thus resulting in inferior quality images. Using a canine model, the role of stannous ion in labeling RBC's both in the presence and absence of a therapeutic dose of heparin was investigated. The systematic investigations described in this paper suggested that 20 micrograms per kiolgrams of body weight regularly provided better than 80% labeling yields even in the presence of therapeutic dose of heparin. Superior quality blood pool images were obtained by this improved procedure.