Clinical comparison of 99mTc-diethyl-IDA and 99mTc-PIPIDA for evaluation of the hepatobiliary system.

Fifteen patients with a wide range of hepatobiliary function were studied with both 99mTc-diethyl-IDA and 99mTc-PIPIDA. In images obtained 5 to 60 minutes after injection, 99mTc-diethyl-IDA was clearly superior with respect to liver/background, hepatic ducts/liver, and small bowel/background ratios. The 99mTc-diethyl-IDA transit time from blood to small intestine averaged 12.2 minutes less than that of 99mTc-PIPIDA. Quantification of relative hepatocyte extraction efficiency indicated that it was 2.15 times higher for 99mTc-diethyl-IDA. Cumulative 3-hour urine collections following injection demonstrated increasing renal excretion of 99mTc-PIPIDA with rising total serum bilirubin levels in a manner quantitatively similar to that determined previously for 99mTc-diethyl-IDA. The authors conclude that 99mTc-diethyl-IDA is superior to 99mTc-PIPIDA for studies of the hepatobiliary system.