During an endoscopic retrograde cholangiopancreatography, a catheter is advanced through the endoscope and inserted into the pancreatic or biliary ducts. A contrast agent is injected into these ducts and X-rays are taken to evaluate their caliber, length and course. Narrowing, stones, and tumors in the ducts can be identified in the X-rays.
Review Date 4/22/2021
Updated by: Michael M. Phillips, MD, Emeritus Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.