originally, any of the rays produced when cathode rays strike upon surface of a solid (as a copper target or the wall of the vacuum tube); now defined as electromagnetic radiation with a wavelength of 0.1 to 10 nanometers. X-rays are noted for their penetration of many opaque substances, as wood and flesh, their action on photographic plates, and their fluorescent effects. They were called X rays by their discoverer, W. K. Röntgen, but were also referred to for some time as Roentgen rays. The term X-ray has become the most common designation. They also ionize gases, but cannot be reflected, or polarized, or deflected by a magnetic field. They are used in examining objects opaque to visible light, as for imaging bones or other structures inside the human body, and for detecting flaws in metal objects, such as in welds.

to examine by means of X-rays; to irradiate with X-rays.

Very short wavelength in the electromagnetic spectrum; can penetrate soft tissue; although it is useful in medical diagnosis, it also damages tissue and causes mutations. [Go to source

a common tool that the doctor may use to help diagnose the cause of joint pain

a black-and-white picture of the inside of the body