Objective: To evaluate the ultrasonographic (US) features distinguishing biliary atresia (BA) from infantile hepatitis syndrome (IHS).
Methods: The US results of infants with obstructive jaundice investigated between 2004 and 2009 were analyzed retrospectively and compared with the clinical and surgical findings, looking for features that distinguished between BA and IHS. US was used to obtain information about the gallbladder shape and the structures of hepatic portal system.
Results: A total of 182 infants were confirmed with intraoperative cholangiogram as having BA (151 cases), HIS (29 cases), or bile duct hypogenesis (2 cases). The gallbladder was visualized by US in 64.24% of BA cases (97/151) and 82.76% of HIS cases (24/29), a difference that was significant (P < 0.05). At US, the mean length of gallbladder was 1.28 cm in BA case and 2.03 cm in HIS cases. The mean volume of the gallbladder was 0.27 mL in BA babies and 0.61 mL in IHS babies, a significant difference (P < 0.05). The diagnostic sensitivity, specificity, and validity of combined visualization of the gallbladder and evaluation of the hepatic portal system were 99.34, 83.87, and 96.7%, respectively.
Conclusions: The ultrasonographic features useful in the differential diagnosis of obstructive jaundice cases are measurement of the gallbladder size, observation of its form, investigations of the triangular cord, and the presence of biliary lake in the area of the hepatic portal system. The validity of a BA diagnosis with these combined ultrasound parameters can, however, be improved effectively.