The short answer: MRCP (magnetic resonance cholangiopancreatography) is an MRI exam of the bile ducts, the pancreatic duct, the gallbladder, the liver, and the pancreas. It uses no radiation and no endoscope. Most centers ask you to fast first. MedlinePlus gives 4 to 6 hours for an abdominal MRI, but the instruction from your imaging center governs. In a Cochrane review, MRCP found about 93% of common bile duct stones.
What is an MRCP scan and what does it show?
MRCP is a type of MRI. The Radiological Society of North America and the American College of Radiology describe it on RadiologyInfo.org as an exam that produces detailed images of the liver, gallbladder, bile ducts, pancreas, and pancreatic duct. It is noninvasive and uses no ionizing radiation.
The bile ducts carry bile from the liver and gallbladder to the small intestine. The pancreatic duct carries digestive juices from the pancreas. Both are thin, fluid-filled tubes. MRCP settings make that still fluid look bright, so the ducts stand out against the organs around them.
Why would a doctor order an MRCP?
An MRCP answers a question about the ducts. RadiologyInfo.org says doctors use it to look for tumors, stones, inflammation, or infection in the liver, gallbladder, bile ducts, pancreas, and pancreatic duct. Common reasons include:
- A suspected bile duct stone. The NIDDK states that MRI can show gallstones in the ducts of the biliary tract. The same page calls ultrasound the best imaging test for finding gallstones in general, so MRCP is rarely the first test.
- Jaundice. The ACR Appropriateness Criteria for jaundice rate MRI with MRCP as "usually appropriate" when a mechanical blockage is suspected.
- Pancreatitis. MRCP can help find the cause. It can also show long-term scarring.
- Unexplained abdominal pain.
Yellow skin, dark urine, or upper belly pain have many possible causes. symptom.md covers common symptoms in plain language.
How is MRCP different from ERCP?
The names are close, but the two tests are very different. MRCP only takes pictures. ERCP (endoscopic retrograde cholangiopancreatography) is a procedure. A doctor passes an endoscope through the mouth to the small intestine, injects dye into the ducts, and takes X-rays. The doctor can remove a stone in the same session.
The NIDDK states that doctors use ERCP to treat problems of the bile and pancreatic ducts. Doctors use it to diagnose only if they expect to treat a problem during the procedure. For diagnosis alone, the NIDDK lists MRCP among the noninvasive tests that carry less risk than ERCP.
That risk is the main reason MRCP often comes first. The NIDDK lists these ERCP complications:
- pancreatitis
- infection of the bile ducts or gallbladder
- excessive bleeding
- a perforation in the ducts or the small intestine
- an abnormal reaction to the sedative
The NIDDK says these problems occur in about 5% to 10% of ERCP procedures. A guideline from the American Society for Gastrointestinal Endoscopy gives a similar range: ERCP is associated with adverse events in 6% to 15% of cases.
In the ACR criteria for jaundice, ERCP is rated "usually not appropriate" as the first imaging test when no cause is yet known. If the MRCP shows a stone, ERCP is then a common way to remove it.
How do you prepare for an MRCP?
Fasting is the main step. RadiologyInfo.org says the rules for eating and drinking before an MRCP vary by facility, and it gives no number of hours. For abdominal MRI in general, MedlinePlus says you may be asked not to eat or drink anything for 4 to 6 hours before the scan. Follow the instruction from your imaging center if it differs.
There is a reason for the fast. A review in the journal Radiology explains that fluid in the stomach can overlap the pancreatic duct on the images and make the duct hard to see. Our guide on eating and drinking before an MRI covers other scan types.
RadiologyInfo.org lists these other steps:
- Tell your doctor about health problems, recent surgery, allergies, and any chance of pregnancy.
- Tell the technologist about any implanted device or metal in your body.
- Take your regular medicines unless your doctor says otherwise.
- Leave jewelry at home and wear loose, comfortable clothes. You may get a gown.
- If closed spaces make you anxious, ask your doctor about a mild sedative before the day of the scan. Our MRI claustrophobia guide has more options.
Does an MRCP use contrast dye or secretin?
The MRCP images themselves need no injected dye. The fluid in the ducts supplies the contrast. Three additions are possible, and each depends on the question your doctor asks.
Gadolinium by vein. MRCP is often done with a full MRI of the abdomen. That part of the exam can use a gadolinium injection. The ACR jaundice criteria list MRI with MRCP both with and without IV contrast. Our guide to MRI with contrast explains the kidney check and the risks.
Oral contrast. RadiologyInfo.org notes that some facilities give a contrast drink for MRCP. Reactions are very rare, but the taste can be unpleasant.
Secretin. Secretin is a hormone that makes the pancreas release fluid. A 2021 expert review in the American Journal of Roentgenology states that secretin-enhanced MRCP helps show duct anatomy and gives insight into pancreatic function. Its established uses include pancreas divisum (a duct variant present from birth) and chronic pancreatitis. Most MRCP exams do not include secretin. The FDA label for human secretin (ChiRhoStim) lists three diagnostic uses, and MRCP is not one of them. Ask your radiologist why secretin is planned if your order includes it.
What is the scan like and how long does it take?
You lie on a table that slides into the scanner. RadiologyInfo.org states that you must lie still and follow breath-hold instructions while the images are recorded. Breathing moves the liver and pancreas, so the breath holds matter. The machine makes loud thumping and humming noises.
MedlinePlus says an abdominal MRI lasts about 30 to 60 minutes, but it may take longer. An MRCP is often one part of that exam. Ask the imaging center for the time planned for your appointment.
MedlinePlus states that an MRI exam causes no pain.
How accurate is MRCP and what are its limits?
For bile duct stones, the accuracy is high. A 2015 Cochrane review pooled seven MRCP studies with 996 participants. The summary sensitivity was 93%, and the summary specificity was 96%. In plain terms, MRCP found about 93 of every 100 stones, and it correctly cleared about 96 of every 100 people without a stone.
The review compared MRCP with endoscopic ultrasound (EUS), a test that uses an ultrasound probe on an endoscope. EUS had a sensitivity of 95% and a specificity of 97%. The authors found no evidence of a difference between the two tests.
The limits are real:
- It can miss a stone. A sensitivity of 93% means some stones are not seen. The Cochrane authors state that people with a negative result need more tests if symptoms persist.
- The evidence has gaps. The authors rated none of the included studies as high in methodological quality. They advise caution with the results.
- It cannot treat. MRCP only takes pictures. It cannot remove a stone.
- Movement blurs the images. RadiologyInfo.org states that image quality depends on how well you stay still and hold your breath.
- Implants and body size. Some implants and metal rule out the scan or distort the image. Some scanners have size and weight limits.
The bottom line
MRCP is an MRI that maps the bile ducts and the pancreatic duct without radiation and without an endoscope. Doctors order it for suspected bile duct stones, jaundice, and pancreatitis. It is a diagnostic test only. ERCP can treat the problem, but NIDDK reports complications in about 5% to 10% of ERCP procedures. Expect to fast, and follow the hours your imaging center gives you. MRCP finds most bile duct stones, but a clear result does not end the workup if your symptoms continue.
Last updated: October 2026. This article is for informational purposes only and does not constitute medical advice. Talk with your doctor or radiologist about which bile duct or pancreas imaging test fits your situation.