The biliary system of liver, bile ducts, and gallbladder are frequently affected by disease or stones that can cause obstruction. When bile builds up in the liver and bloodstream and cannot drain properly, the pigment and toxins can cause symptoms such as yellowing of the skin and eyes (jaundice) and itching. Stagnant bile can also become infected. It is important to try to relieve the pressure on the biliary system so that the bile can drain properly. One way of doing this is by placing a small, flexible catheter directly into the liver into a bile duct. Often, the catheter can be guided over a wire using interventional radiology techniques through the bile ducts into the small bowel, allowing the bile to drain directly into the intestine where it belongs. If the obstruction is too great, the tube can be left to external drainage and the bile collected in a drainage bag. This procedure, along with diagnostic imaging using dye, is referred to as a PTC, or Percutaneous Transhepatic Cholangiogram. Interventional Radiologists are also able to place stents into the biliary system to maintain patency of the ducts, and to open up the ducts with small balloons to allow better flow.