THE DEVELOPMENT of radiopharmaceuticals that localize within the hepatobiliary system has facilitated evaluation of many difficult clinical problems, particularly differentiation between surgical and medical jaundice.
In 1909, Abel and Rountree found that certain phenolphthalein dyes were excreted almost exclusively by the biliary system, and developed a clinical test of liver function based on measurement of fecal excretion of the dye. Sulfobromophthalein was later found to be superior to the other dyes for hepatic-clearance study, and in 1923 rose bengal was introduced by Delprat as a possible alternative. With use of fluorescent techniques, Mendeloff showed that stable rose bengal concentrated only in the polygonal cells and not in the reticuloendothelial cells. This knowledge led to Taplin's labeling of rose bengal with iodine 131, and permitted detection and imaging of the labeled dye as it was cleared from the blood, localized in the hepatocytes, and excreted into the bile en route to