A cross-over study comparing the kinetics of Tc-99m-labeled diisopropyl and p-butyl IDA analogs in patients.

Tc-99m-diisopropyl-IDA (DISIDA) and Tc-99m-p-butyl-IDA (BIDA) were compared in each of 33 patients who had serum bilirubins ranging from normal to 23.5 mg/dl. DISIDA exhibited quantitatively a higher liver uptake and faster rate of washout at all levels of bilirubinemia. There was a tendency for BIDA to have a slower blood clearance, particularly in hyperbilirubinemias exceeding 5 mg/dl. On visual comparison of the images, BIDA failed to identify the gallbladder in three icteric patients and dilated biliary tracts in two others.