Cholangiogram is an imaging test used to evaluate the bile ducts. It shows the path bile takes from the liver to the duodenum (small intestine).
This test can help identify bile duct blockages, gallstones, or tumors. It may be done with X-rays and a radiologic contrast agent, with an endoscope during ERCP, or with MRI during MRCP, depending on the type of cholangiogram.
A cholangiogram can help diagnose or treat conditions that affect the bile ducts. It is performed by a gastroenterologist or radiologist in specialized clinics or hospitals.
What it's for
A cholangiogram is indicated for:
-
Gallstones
-
Inflammation of the bile ducts or gallbladder
-
Tumor or cancer of the gallbladder
-
Acute or recurrent pancreatitis
-
Bile duct injuries after surgery
-
Pancreatic fistula
In addition, a cholangiogram may be indicated to help diagnose the cause of unexplained jaundice.
A cholangiogram is an imaging test usually ordered by a gastroenterologist or a hepatologist (liver specialist). It allows the doctor to look for blockages, dilation, or injuries in the bile ducts.
How to prepare
Preparation for a cholangiogram may vary depending on the type of test. However, general instructions include:
-
Fasting for 6 to 12 hours
-
Drinking only small sips of water up to 2 hours before the test
-
Telling the doctor about any medications being used, especially aspirin, clopidogrel, or warfarin
In some cases, the doctor may also request a blood test up to 2 days before the procedure.
How it's done
A cholangiogram is performed by a gastroenterologist or radiologist using different techniques, such as X-ray with contrast, endoscopy, MRCP, fluoroscopy, or ultrasound.
How the test is performed depends on the type of cholangiogram.
Main types
The main types of cholangiogram are:
1. Intravenous cholangiogram
An intravenous cholangiogram is an imaging test in which a contrast dye is injected into a vein. As the dye is excreted into the bile, X-ray images are taken to visualize the bile ducts.
After this, images are taken every 30 minutes. This allows the doctor to assess how the contrast moves through the bile ducts.
2. ERCP
ERCP, or endoscopic retrograde cholangiopancreatography, uses an endoscope. This is a tube with a light and camera at the tip that allows the doctor to see the bile ducts from the inside.
The endoscope is inserted through the mouth until it reaches the duodenum. A radiologic contrast agent is then administered, and an X-ray of the area is taken.
3. Intraoperative cholangiogram
An intraoperative cholangiogram is performed during gallbladder removal surgery, called cholecystectomy. During the procedure, contrast is administered and several X-rays are taken.
4. MRCP
MRCP, or magnetic resonance cholangiopancreatography, is an MRI test used to evaluate the liver, gallbladder, bile ducts, pancreas, and pancreatic duct. It may be used to identify stones, tumors, inflammation, infection, or other bile duct problems.
5. Postoperative cholangiogram
A postoperative cholangiogram is performed after gallbladder removal surgery to prevent and monitor complications or blockages caused by residual stones. A catheter is usually placed in the bile duct.
6. Percutaneous transhepatic cholangiogram
A percutaneous transhepatic cholangiogram is performed by inserting a needle through the skin and into the liver to access the bile ducts. Contrast is then injected, and X-rays are taken.
This type of cholangiogram may be guided by ultrasound or fluoroscopy to accurately locate the bile ducts where the needle will be inserted.
Possible risks
Although they are not very common, some risks may be associated with a cholangiogram, especially when the test is performed as ERCP.
According to the National Institute of Diabetes and Digestive and Kidney Diseases, ERCP may lead to complications such as pancreatitis, infection, bleeding, and perforation.
After a cholangiogram, if symptoms such as fever above 101.3ºF (38.5ºC) or abdominal pain that does not improve occur, it is recommended to go to the hospital.
Contraindications for the procedure
Although this test is considered safe, it is not recommended for people who are allergic to contrast agents, have an infection in the biliary system, or have high creatinine levels or high BUN.
In these cases, the doctor may recommend another test to evaluate the bile ducts.