A study of o-cresolphthalexon and its analogs as cholescintigraphic 111In carriers.

111In has been complexed to a series of metal-complexing phthaleins and sulfonphthaleins, and the hepatobiliary excretion of the compounds were compared in rats. The highest biliary excretion was obtained with 111In-o-cresolphthalexon. In a normal human subject, sequential imaging with 111In-o-cresolphthalexon visualized his gallbladder, common bile duct, and the bowel from jejunum to rectum. The potential utility and limitation of this biliary scanning agent is discussed.