Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Primary Sclerosing Cholangitis ?
    ### Response:
    Blood tests to check levels of liver enzymes are the first step in diagnosing PSC. Doctors confirm the diagnosis using cholangiography, which provides pictures of the bile ducts.
                
Cholangiography can be performed in the following ways:
                

    