• Definition
    • X-rays are a type of electromagnetic radiation, just like visible light.

      An x-ray machine sends individual x-ray particles through the body. The images are recorded on a computer or film.

      • Structures that are dense (such as bone) will block most of the x-ray particles, and will appear white.
      • Metal and contrast media (special dye used to highlight areas of the body) will also appear white.
      • Structures containing air will be black, and muscle, fat, and fluid will appear as shades of gray.
  • Alternative Names
    • Radiography

  • How the Test is Performed
  • How to Prepare for the Test
    • Before the x-ray, tell your health care team if you are pregnant, may be pregnant, or if you have an IUD inserted.

      Metal can cause unclear images. You will need to remove all jewelry and you may need to wear a hospital gown.

  • How the Test will Feel
    • X-rays are painless. Some body positions needed during an x-ray may be uncomfortable for a short time.

  • Risks
    • X-rays are monitored and regulated so you get the minimum amount of radiation exposure needed to produce the image.

      For most x-rays, the risk of cancer or defects is very low. Most experts feel that the benefits of appropriate x-ray imaging greatly outweigh any risks.

      Young children and babies in the womb are more sensitive to the risks of x-rays. Tell your health care provider if you think you might be pregnant.

  • References
    • Geleijns J, Tack D. Medical physics: radiation risks. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. 6th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2014:chap 1.

      Mettler FA, Jr. Introduction: an approach to image interpretation. In: Mettler FA, ed. Essentials of Radiology. 3rd ed. Philadelphia, PA: Saunders Elsevier; 2013:chap 1.