Mechanisms of Localization:

Phagocytosis

•  Reticuloendothelial system imaging is performed following the phagocytosis of radiocolloid particles by Kupffer cells in the reticuloendothelial System following IV injection od the radiolabeled colloid
   
•  Radiopharmaceutical: Tc-Sulfur Colloid
   
•  Diameter of average capillary is 7 mm. Particle size range of Tc-SC is 0.1-2.0 mm, so capillary blockade does not occur.
   
•  Distribution in RE System: 80-90% in liver, 5-10% in spleen; 5-10% in marrow.
   
•  t_biol of Tc-SC: infinitely long
   
•  t_1/2 of clearance from the blood pool: 2.5 min
   
•  Imaging performed 10 min  p