Ultrasound diagnosis of biliary ascariasis.

Two patients with right upper quadrant pain underwent real time ultrasound examination and biliary ascariasis was diagnosed. One case was confirmed by endoscopic retrograde cholangiopancreatography with removal of the parasites, and the other by intravenous cholangiography. Patients with ascariasis in the bile duct occasionally presenting with atypical right upper quadrant abdominal pain can be diagnosed accurately by real time ultrasound, which shows the movement of the worms.