Serial ultrasonic examination to differentiate biliary atresia from neonatal hepatitis--special reference to changes in size of the gallbladder.

We performed serial ultrasonic examinations to differentiate biliary atresia from neonatal hepatitis. The subjects studied were 144 children (100 normal neonates and infants, 31 patients with neonatal hepatitis and 13 patients with biliary atresia). They were examined by ultrasound before, during and after feeding. In 97 out of 100 normal children and all patients with neonatal hepatitis, the gallbladder was identified, and the change in size following oral feeding was observed. In four children with severe neonatal hepatitis which could not be differentiated from biliary atresia by clinical and laboratory data, we readily identified the gallbladder and observed the change in the size following oral feeding. In 8 of 13 patients with biliary atresia, we identified a small gallbladder whose size was not affected by oral feeding. In the other patients the gallbladder was not identified before, during or after oral feeding. On the basis of these results, we consider that serial ultrasonic examination with oral feeding aids in a differential diagnosis of biliary atresia and neonatal hepatitis.