Gallbladder and biliary tree. Three-dimensional magnetic resonance image (MRI) showing the gallbladder (round) and biliary tract (branching). This imaging technique is known as magnetic resonance cholangiopancreatography (MRCP) when used to image this area of the body. The biliary tree is the collection of vessels through which bile passes from the liver, where it is produced, and into the duodenum and small intestine where it aids digestion of fats (lipids). The gallbladder stores bile. Here the gallbladder and biliary tree are distended due to gallstones and a stricture (narrowing, not seen).