Percutaneous transhepatic cholangiography (PTC) is a procedure for obtaining x-ray images of the bile system.  In this sense, it is similar to ERCP; however it does not involve the use of endoscopy.

A specialist inserts a fine needle through the skin in the right side of abdomen and into the liver.  The doctor then injects dye (contrast material) into the bile duct in the liver so that any growths, strictures, or blockages of the bile duct system will be more apparent on x-rays. 

The procedure may also involve removing some biopsy material (fluid or tissue for microscopic examination in the laboratory).

In some cases, if the specialists identify an obstruction of the bile ducts, they will replace the thin needle with a small drainage tube.  This is so that the bile fluid will not build up and back up, causing damage to the liver.  A small pouch connected to the tube outside of your body collects the bile.

Patients fast before PTC and receive a mild sedative just prior to the procedure.