Biologic evaluation of radiocolloids for bone marrow scintigraphy

The validity of a primate animal model for studying the in vivo distribution of various colloids was established. Computerized images from two adult baboons injected with technetium-99m labeled sulfur colloid, stannous phytate and microaggregated albumin were analyzed to give the relative uptake of radioactivity in the liver, spleen and bone marrow. These values were in good agreement with those previously established in several animal species and in man. Antimony sulfide colloid and minimicroaggregated albumin, each having a significantly smaller particle size than Tc-99m sulfur colloid were evaluated. Compared with sulfur colloid the minimicroaggregated albumin showed three times the bone marrow uptake (15 to 20%) whereas microaggregated albumin and antimony sulfide gave somewhat lower values (8 to 12%). The stannous phytate showed no improvement over Tc-99m sulfur colloid