Modern imaging in patients with obstructive jaundice : main article

Cholestatic jaundice caused by intrahepatic hepatocellular disease may be clinically and biochemically indistinguishable from cholestasis due to extrahepatic bile duct obstruction. The most common intrahepatic causes of jaundice are viral hepatitis, alcohol-induced hepatitis, cirrhosis and drug-induced jaundice. Extrahepatic jaundice is most often due to a stone in the common bile duct or a pancreaticobiliary malignancy. Pancreatic pseudocysts, chronic pancreatitis, sclerosing cholangitis, benign bile duct strictures or parasites in the bile duct are less common causes. Ultrasound is a useful initial investigation because it is non-invasive and assesses pancreaticobiliary structures in real-time without exposing the patient to ionising radiation. Dilated ducts are indirect evidence of biliary obstruction. If bile ducts are not dilated, hepatocellular disease is the likely diagnosis; however, parenchymal liver disease or sclerosing cholangitis may prevent biliary dilatation despite obstruction being present.