Introduction An X ray, also called roentgen ray, is electromagnetic radiation of shorter wavelength than visible light that has been used for over 100 years to see view structures hidden from the eye. X rays, which can penetrate most substances, can be focused and aimed at specific targets such as part of the body.
X rays pass through organs and structures of the body onto a photographic plate.
The difference in X ray penetration, and thus exposure of the photographic plate, depends on the density and thickness of the tissue the X ray passes through. Less radiation will pass through bone than other tissues. Areas of the photogrphic plate with less exposure are lighter in color. Thus bones will appear white while the lungs normally appear darker. Appropriate uses of X rays It is known by most people that Xrays can be used to diagnose broken bones and that chest Xrays can be used to diagnose pneumonia.