Ultrasound has a very high sensitivity and specificity for detecting gallbladder stones, and also to rule out associated inflammation (cholecystitis). Ultrasound will also show dilation of the ducts which can be caused by various mechanisms. The exact cause is, however, not always demonstrated by ultrasound, so further imaging with CT or MRI in these circumstances may be necessary.
NM biliary scintigraphy shows cystic duct obstruction in acute cholangitis, will visualise post-operative bile leakage, and can diagnose biliary atresia.
