What is it ?
X-rays are a form of radiant energy, which penetrate various tissues of the body differentially, in the process capturing shadows and reflections on the photographic plate.

The radiologist can view these on photographic film, on a TV or computer monitor. The films created by X rays show different features of the body in various shades of gray.

Some X-ray exams improve visibility by using contrast, a range of substances, which are opaque to X-rays. The contrast may be introduced by injection, patient swallowing the dye himself or enema. In fluoroscopy, X-rays are used to capture a moving image of an organ on the screen while it's functioning.