Biliary atresia: making the diagnosis by the gallbladder ghost triad.

OBJECTIVE

To describe the gallbladder ghost triad and evaluate its usefulness in the sonographic diagnosis of extrahepatic biliary atresia (BA).

METHODS

From October 1997 to February 2002, 217 fasted infants with cholestatic jaundice aged 2-12 weeks were examined sonographically. We defined the gallbladder ghost triad as gallbladder length <1.9 cm, lack of smooth/complete echogenic mucosal lining with an indistinct wall and irregular/lobular contour, and used it as a criteria for BA. Gallbladder wall thickness, triangular cord, diffuse periportal echogenicity and hepatic artery calibre were also recorded. Diagnosis of BA was confirmed surgically and histologically.

RESULTS

Thirty of 31 babies with BA demonstrated the gallbladder ghost triad. No false-positives were recorded. The 31st BA baby showed a normal gallbladder at 6 weeks, but developed the ghost triad at 8 weeks. Gallbladder wall thickening was seen in 46/186 non-BA babies, but not in BA. Triangular cord was observed in 24/31 babies. Twenty-two of 186 non-BA babies and 5/31 BA babies showed diffuse periportal echogenicity. The hepatic artery appeared more prominent in BA. All 31 babies diagnosed sonographically as BA had surgery. Three non-BA babies had "negative" laparotomies showing hypoplastic bile ducts.

CONCLUSIONS

The gallbladder ghost triad is a very accurate sign of BA. Indeterminate cases require close follow-up.