PTHC is also used in the drainage of unruptured or uncomplicated hydatid cysts. Rarely it is used for diagnostic purposes only. PTHC is frequently performed guide therapy of the biliary system. In this rendezvous technique, the guidewire is then pulled into duodenoscope and a small blade is slid over the guidewire into the CBD and perform surgeries on a specific bile duct in the biliary system. Some uses for this procedure includes: drainage of bile/infected bile to relieve obstructive jaundice, to place a stent to dilate a stricture in the biliary system, stone removal, and rendezvous technique where guidewire from the common bile duct (CBD) meets with duodenoscope (coming from the oesophagus into the stomach and then duodenum) at the major duodenal papilla. Initially reported in 1937, the procedure became popular in 1952. It allows access to the biliary tree in cases where endoscopic retrograde cholangiopancreatography has been unsuccessful. A contrast medium is injected into a bile duct in the liver, after which X-rays are taken. Percutaneous transhepatic cholangiography, percutaneous hepatic cholangiogram ( PTHC) is a radiological technique used to visualize the anatomy of the biliary tract.