Anode heel effect

Dr Aditya Shetty et al.

Anode heel effect refers to the intensity of the x-ray beam, produced from the X-ray tube, which is not uniform in all portions of the beam.

Basic concept

In general, the beam consists of a central ray and a diverging beam. The rays towards the cathode end of the tube have more intensity. This is because, in a diverging beam, the rays which are parallel or near parallel to the inclined/angulated anode get absorbed by the anode itself.


  1. intensity of beam on the anode side is less than cathode side: therefore place the thicker part of the body on the cathode side, e.g. upper thoracic on the anode side and lower thoracic or upper abdomen should be placed on the cathode side.
  2. target-to-film distance: increase in distance reduces heel effect.
  3. size of film (keeping target-to-film distance as constant ): the smaller film has lesser heel effect as the divergent beam does not reach the film and intensity of the beam is more uniform at centre than at the periphery.
Share article

Article information

rID: 29775
Section: Physics
Tag: shetty
Synonyms or Alternate Spellings:
  • Heel effect

Support Radiopaedia and see fewer ads

Updating… Please wait.

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.