Clinical application of spontaneous red blood cell labeling with Tc-99m sodium pertechnetate.

Red blood cells (RBC) may be labeled with Tc-99m after Tc-99m sodium pertechnetate is injected in the presence of a reducing agent, such as stannous chloride. Thus, spontaneous RBC labeling with Tc-99m is expected to be seen in patients with a high plasma concentration of tin. Spontaneous RBC labeling with Tc-99m was obtained in a 73-year-old woman who was clinically diagnosed with tin intoxication and proved to have a high concentration of plasma tin. The RBC labeling rate was calculated as 96% with blood sampling. Spontaneous RBC labeling with Tc-99m is a very simple method for proving a high plasma tin concentration and is adaptable to clinical diagnosis.