Visualization of the hepatic and biliary ducts is difficult to obtain before operation when the gall bladder has either been removed or does not function. The use of sodium iodipamide (Biligrafin) by intravenous injection is sometimes satisfactory but is not satisfactory in the presence of jaundice and liver failure. A needle may, however, be introduced into the hepatic ducts by passing it through the skin and the liver, and when the duct system has been entered and bile aspirated, idopyracet (Diodone) may be injected and will give a satisfactory visualization of the ducts. This method has been used in a number of cases and with proper technique will show the site and nature of the obstruction; it also allows the pressure in the bile ducts to be recorded, and specimens of bile taken for chemical and bacteriologic investigation. Carter and Saypol (1952), with the patient under general anesthesia, injected ducts