Making the diagnosis of biliary atresia using the triangular cord sign andgallbladder length

Background. To evaluate the accuracy and utility of the triangular cord sig n and gallbladder length in diagnosing biliary atresia by sonography. Materials and methods. Sixty fasted infants with cholestatic jaundice aged 2-12 weeks were examined sonographically using a 5-10 MHz linear array tran sducer, focusing on the triangular cord sign (as described by Choi et al. [ I]), the gallbladder, and ducts. The triangular cord is defined as a triang ular or tubular echogenic density seen immediately cranial to the portal ve in bifurcation; it represents the fibrotic remnant of the obliterated cord in biliary atresia. The findings were blinded to blood chemistry, Tc-99m-DI SIDA hepatobiliary scintigraphy, and liver biopsy. Diagnosis of biliary atr esia was confirmed at surgery and histology. Non-biliary atresia infants re solved medically. Comparative charges of the various investigations was mad e. Results. Twelve infants had biliary atresia, and ten demonstrated a definit e triangular cord. The two false-negatives had small or nonvisualized,gallb ladders. No false-positives were recorded. Gallbladder length ranged from 0 -1.45 cm with a mean of 0.52 cm in biliary atresia compared to a mean of 2. 39 cm in nonbiliary atresia infants. Tc-99m-DISIDA hepatobiliary scintigrap hy showed no excretion (false-positive) in 23 % of nonbiliary atresia cases . Scintigraphy and liver biopsy charges were 2 and 6 times that of sonograp hy, respectively. Conclusion. The triangular cord sign and gallbladder length together are no ninvasive, inexpensive, and very useful markers for biliary atresia.