X-RAY:
Since their discovery in 1895, x-rays have been a vital scientific tool, revealing previously concealed worlds. Because of their great penetrating power, x-rays can also be used to study the structure of living organisms.

One of the earliest applications of x-rays was in medicine, where they were used for both diagnosis and therapy. They penetrate soft tissues but are stopped by bones, which absorb them. Thus if a photographic plate that is sensitive to x-rays is placed behind a part of the body and an x-ray source is placed in front, x-ray exposure will result in an image of the bones and internal organs. When the radiograph, or plate, is developed, a negative image is produced. Tissues that are easily penetrated by x-rays appear dark, while bones and dense tissues show up as light or white regions. Although bones are the most opaque structures, there are many dense tissues, such as tumors, that can also show up unusually light in radiographs. These images can be used to study damaged or broken bones, inspect dental cavities, detect foreign objects in the body, and diagnose diseases.

To utilize x-rays for the investigation of other, less dense tissues of the body, such as the gastrointestinal tract, the tissues must first be made opaque to x-rays. Generally, patients are asked to drink a mixture containing an opaque substance, such as barium, so that the outline of the digestive tract becomes visible with x-rays.

The clinic also offers fluoroscopy, a similar technique that uses x-rays to observe a particular organ in action, such as the heart. The patient is placed in the fluoroscope between the x-ray source and a screen that is coated with a fluorescent substance. The image that appears when the x-rays strike the screen is brightened by an electronic device called an image intensifier.