Clinical studies with spleen-specific radiolabeled agents.

While 99mTc sulfur colloid imaging, because of its availability and convenience, remains the initial procedure of choice for spleen imaging, selective spleen scanning with damaged 99mTc-labeled RBCs can provide additional information in some cases. These cases include overlapping left hepatic lobe and suspected splenic pathology but with poor radiocolloid uptake that precludes visualization. Other indications are detection of residual splenic tissue after splenectomy, suspected asplenia, polysplenia, and situs ambiguus. The selective 99mTc-denatured RBC scan is most useful to confirm or exclude defects seen on the radiocolloid study and to detect small amounts of splenic tissue.