Renal concentration of131I-Rose Bengal confusing the interpretation of abdominal scans in liver disease

The renal excretion of radioiodinated Rose Bengal is significantly increased in patients with severe intrahepatic disease as well as those with obstruction of their extrahepatic biliary tracts. Based upon experimental evidence it is suggested that free 131I dissociated from Rose Bengal, in vivo, accounts for most of this urinary activity. Renal excretion of radioiodinated Rose Bengal on a scan must be distinguished from intestinal activity to avoid a mistaken impression of biliary tract patency in cases where an obstruction actually exists. Serial and lateral scans are very helpful in this regard.