Diagnosis

Tests and procedures used to diagnose primary sclerosing cholangitis include:

• Liver function blood test. A blood test to check your liver function, including levels of your liver enzymes, can give your doctor clues about your diagnosis.
• MRI of your bile ducts. Magnetic resonance cholangiopancreatography (koh-lan-jee-o-pan-cree-uh-TOG-ruh-fee) uses magnetic resonance imaging (MRI) to make images of your liver and bile ducts and is the test of choice to diagnose primary sclerosing cholangitis.

• X-rays of your bile ducts. A type of bile duct X-ray called endoscopic retrograde cholangiopancreatography (ERCP) in addition to, or instead of, an MRI may be needed. But this test is rarely used for diagnosis because of the risk of complications.

  To make your bile ducts visible on an X-ray, your doctor uses a flexible tube passed down your throat to inject dye into the area of your small intestine where your bile ducts empty.

  An ERCP is the test of choice if signs and symptoms persist despite no abnormalities on an MRI. An ERCP is often the initial test if you're unable to have an MRI because of a metal implant in your body.

• Liver biopsy. A liver biopsy is a procedure to remove a piece of liver tissue for laboratory testing. Your doctor inserts a needle through your skin and into your liver to extract a tissue sample.

  A liver biopsy can help determine the extent of damage to your liver. The test is used only when the diagnosis of primary sclerosing cholangitis is still uncertain after less-invasive tests.