Conclusion The water-filled colon can be used as the acoustic window of extrahepatic bile duct, which makes the ultrasonic diagnosis much more sensitive to the extrahepatic bile duct obstruction.

• 结论被生理盐水充盈的结肠确能作为肝外胆管的透声窗，从而使肝外胆管梗阻病变的超声显示率显著提高。