Cracking, in petroleum refining, the process by which heavy hydrocarbon molecules are broken up into lighter molecules by means of heat and usually pressure and sometimes catalysts. Cracking is the most important process for the commercial production of gasoline and diesel fuel. 1  Cracking of petroleum yields light oils (corresponding to gasoline), middle-range oils used in diesel fuel, residual heavy oils, a solid carbonaceous product known as coke, and such gases as methane, ethane, ethylene, propane, propylene, and butylene.
Cholangiography is the imaging of the bile duct (also known as the biliary tree) by x-rays. percutaneous transhepatic cholangiography (PTC): Examination of liver and bile ducts by x-rays. This is accomplished by the insertion of a thin needle into the liver carrying a contrast medium to help to see blockage in liver and bile ducts.
Diagnostic and Interventional Angiography. Angiography is a procedure in which blood vessels (arteries or veins) are injected with a dye that shows up on X-Ray to detect narrowing or blockages.he procedure may be for diagnostic purposes (Diagnostic Angiography) at which time only X-Ray images of the blood vessels are obtained; or the procedure may include treatment (Interventional Angiography) which includes inserting a small stent to inflate and open the vessel. Find A Doctor.