This xray has been taken during percutaneous trans-hepatic cholangiography. A fine tube has been passed into the liver and then, via the bile duct system, down the common bile duct into the duodenum. This technique is most often used in obstruction of the common bile duct when ERCP has proved to be impossible. A guide wire can then be placed through the malignant structure and a stent passed over the guidewire to alleviate the jaundice.