Biliary dilatation: Meaning in a Radiology Report

Also written as: biliary dilation, dilated bile ducts, biliary ductal dilatation, dilated common bile duct

Biliary dilatation means the bile ducts, the tubes that carry bile from the liver to the gut, are wider than usual.

What it means

Bile is a digestive fluid made in the liver. It drains through a tree of small ducts inside the liver, then down the common bile duct into the small intestine. When the flow is slowed or blocked, the ducts above the problem widen, like a hose behind a kink. Reports say whether the widening is inside the liver (intrahepatic), outside it (extrahepatic) or both, and give the duct's width in millimeters.

When it matters

Mild widening is often harmless. The duct can widen a little with age and is often wider after gallbladder removal. Doctors look more closely when the widening is new or marked, or comes with pain, fever, yellowing skin (jaundice) or abnormal liver blood tests. Causes include a stone in the duct, a narrowing and, less often, a growth. Next steps may include blood tests, an MRI of the ducts (MRCP) or an endoscopic ultrasound.

Questions to ask your doctor

Could my age or past gallbladder surgery explain the widening?
Is anything blocking the duct, such as a stone or a narrowing?
Do my liver blood tests fit with this, and do I need an MRCP?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.