Choledocholithiasis refers to the presence of gallstones within the common bile duct (CBD), which can obstruct bile flow and lead to biliary colic, jaundice, cholangitis, and pancreatitis. Ultrasound plays a key role in identifying CBD dilation (>6 mm in adults without prior cholecystectomy) and, when stones are visible, demonstrating echogenic foci with posterior acoustic shadowing within the duct. Direct visualization of CBD stones on ultrasound has moderate sensitivity (50–75%) but high specificity. When ultrasound is inconclusive, magnetic resonance cholangiopancreatography (MRCP) or endoscopic ultrasound (EUS) may be used. Treatment is typically endoscopic stone extraction via ERCP.
Associated Anatomy: Common Bile Duct
Signs & Symptoms: Jaundice, right upper quadrant pain, elevated bilirubin and liver enzymes, fever (if cholangitis)
ICD-10: K80.5