What Are X-Rays?

  • X-rays are a type of electromagnetic radiation, just like light rays but with much higher energy.
  • X-rays can penetrate through body tissues, allowing images of the skeleton and certain organs to be created, unlike light waves which are reflected or absorbed by the skin.
  • The ability of X-rays to penetrate tissues and organs varies, providing contrast in the image produced. Hard tissues like bones absorb more X-rays, appearing white on the image, while soft tissues absorb less, appearing darker.

Generation and Detection of X-Rays

  • Inside the X-ray tube, an electron is accelerated by an electric field and hits a metal target. As the electron loses its energy, X-rays are produced.
  • The produced X-rays move in all directions, but only the rays directed towards the patient are used. The rays then pass through the patient and hit a detector on the other side.
  • The detector, typically a phosphor screen or a digital detector, absorbs the X-rays and creates an image.

Medical Applications of X-Rays

  • Medical imaging: X-rays are primarily used for imaging bones and teeth. They are also used in mammograms for early detection of breast cancer.
  • Treatment: High energy X-rays can be used to kill cancer cells in radiation therapy.
  • Cardiology and angiography: By injecting a contrasting agent into blood vessels, clotting and blockages can be identified with X-rays.

Safety Measures and Risks of X-Rays

  • As X-rays involve radiation exposure, judicious use is advised in order to avoid potential harm, especially in pregnant women and children.
  • Protective shields made of lead are often used to protect the body parts not being imaged from unnecessary exposure.
  • Although occasional exposure to X-rays is considered safe, repeated exposure could increase the risk of cancer. However, the benefits of their medical use often outweigh the associated risks.

Understanding X-rays and their applications is a key component of Medical Physics.