X- rays have two uses in medicine:
as diagnostic aids
and as a treatment for cancer
They were discovered in 1895 by Wilhelm Roentgen, professor of physics at Wurzburg, Germany, who found that when a strong electric discharge was directed from the cathode in a vacuum tube on to a metal plate, also in the vacuum tube, a new kind of radiation was produced. These rays passed through paper, wood and flesh, but not through metal or bone. They also darkened photographic film. Roentgen named them X, meaning unknown.
The development of the gamma-camera and of scanners has reduced the harmful effects of x-rays. Many of the early research workers suffered burns, ulcers and cancers from using x-rays. But the damaging effect of radiation on living tissue could be used to good effect in the treatment of cancers, and a new form of medicine developed called radio-therapy.