Biliary excretion disorders in infants: evaluation using 99mTc PIPIDA.

A new class of hepatobiliary imaging agents has become available--the N-substituted iminodiacetic acids. After intravenous administration, these compounds are quickly extracted by the hepatocytes and rapidly excreted into the biliary tree. By using a 99mTc label, sufficient activity may be given to allow excellent gamma-camera imaging, 99mTc-labeled p-isopropylacetanilido-iminodiacetic acid (PIPIDA) has been used in the evaluation of infants with biliary excretion disorders, including two infants with neonatal hepatitis, three with intrahepatic cholestatic jaundice, and 10 with biliary atresia. Follow-up evaluation of surgically created portoenterostomies has been performed as well. In comparison with the previously available agent (131I rose bengal), the marked reduction in radiation to the liver alone should predicate the use of 99mTc PIPIDA. In addition, the speed of handling of this agent by the liver and the vastly improved imaging statistics make 99mTc PIPIDA a desirable agent for the evaluation of biliary excretion disorders in infancy.