Following intravenous administration, Technetium Tc 99m Sulfur Colloid Injection is rapidly cleared by the reticuloendothelial system from the blood with a nominal clearance half-life of approximately 2 1/2 minutes. Uptake of the radioactive colloid by organs of the reticuloendothelial system is dependent upon both their relative blood flow rates and the functional capacity of the phagocytic cells. In the average patient 80 to 90% of the injected colloidal particles are phagocytized by the Kupffer cells of the liver, 5 to 10% by the spleen and the balance by the bone marrow.

Following administration of Technetium Tc 99m Sulfur Colloid Injection by intraperitoneal injection, the radiopharmaceutical mixes with the peritoneal fluid. Clearance from the peritoneal cavity varies from insignificant, which may occur with complete shunt blockage, to very rapid clearance with subsequent transfer into the systemic circulation when the shunt is patent.

Serial images should be obtained of both the shunt and liver (target organ). However, an adequate evaluation of the difference between total blockage of the shunt and partial blockage may not be feasible in all cases.

Last reviewed on RxList: 3/4/2009
This monograph has been modified to include the generic and brand name in many instances.