DIAGNOSING EXTRAHEPATIC BILE-DUCT STONES USING INTRADUCTAL ULTRASONOGRAPHY - A CASE SERIES

Background and Study Aims: Intraductal ultrasonography (IDUS). a new u ltrasonographic diagnostic procedure, was used to assess the presence of extrahepatic bile duct stones. Patients and Methods: The IDUS appar atus consisted of a 6-French high-frequency (20 MHz) probe, Prior to c linical application, in-vitro studies were conducted in a water tank, Clinically, IDUS was successful in 31 patients after endoscopic retrog rade cholangiography. Interpretations of IDUS images were evaluated in comparison with cholangiographic and fluoroscopic findings. Results: Experimental testing demonstrated that stones or fragments were typica lly visualized as strong, high-echo images with acoustic shadowing: ai r bubbles were seen as fan-shaped high-echo areas or comet-shaped high -echo areas: and sludge was visualized as soft, easily changing, high- echo structures, Extrahepatic bile duct stones were visualized by IDUS in 30 of 31 patients (96.8 %) while fluoroscopy and cholangiography i dentified 19 (61.3 %) and 25 (80.6%), respectively. Accurate different iation between stones and air bubbles was also possible. Conclusion: I DUS could be a useful modality in the diagnosis of extrahepatic bile d uet stones.