An X-Ray Device directs electromagnetic radiation upon a specified region in the body. This radiation tends to pass through less dense matter and absorbed or scattered by denser materials . In Film-Screen Radiography, radiation which has passed through a patient then strikes a cassette containing a screen of fluorescent phosphors and exposes x-ray film. Areas of film exposed to higher amounts of radiation will appear as black or grey on X-ray film while areas exposed to less radiation will appear lighter or white. In Computed Radiography (CR), the x-rays passing through the patient strike a sensitized plate which is then read and digitized into a computer image by a separate machine. In Digital Radiography the x-rays strike a plate of x-ray sensors producing a digital computer image directly.