INTRAHEPATIC BILE-DUCT ULTRASOUND - IMPLI CATIONS OF THE COMET-TAIL ARTIFACT

Objectives. - The aim of this study was to evaluate the sensitivity an d specificity of the ultrasound intrahepatic bile duct wall comet-tail artifact for the diagnosis of biliary disease. Methods. - All subject s who underwent upper abdominal ultrasound examination were included i n the study over an 18-month period. The presence or absence of the co met-tail artifact (that is hyperechoic pattern with several parallels lines, constant, lining on the intrahepatic biliary ducts) was noted. Results. - Fourteen thousand four hundred and ninety-eight patients we re included. The comet-tail artifact was only found in 10 of the 14 21 1 patients without biliary tract disease (99.9 % specificity), but in 35 of the 287 patients with biliary disease (12.2 % sensitivity): The positive predictive value for the diagnosis of biliary tract disease w as 77.7 %. The artifact was associated with an angiocholitis in 83 % o f the patients. Conclusion. - Despite its low sensitivity, the sonogra phic comet-rail artifact of the intrahepatic bile duct wall was strong ly correlated with the presence of biliary disease. This artifact may be related to an enlargement ofthe bile duct wall.