Automatic exposure control

Last revised by Andrew Murphy ◉ on 9 Mar 2023

Citation, DOI, disclosures and article data

Citation:

Vajuhudeen Z, Murphy A, Howden W, et al. Automatic exposure control. Reference article, Radiopaedia.org (Accessed on 30 May 2023) https://doi.org/10.53347/rID-79836

DOI:

https://doi.org/10.53347/rID-79836

Permalink:

https://radiopaedia.org/articles/79836

rID:

79836

Article created:

5 Jul 2020, Zemar Vajuhudeen

Disclosures:

At the time the article was created Zemar Vajuhudeen had no recorded disclosures.

View Zemar Vajuhudeen's current disclosures

Last revised:

9 Mar 2023, Andrew Murphy ◉

Disclosures:

At the time the article was last revised Andrew Murphy had no financial relationships to ineligible companies to disclose.

View Andrew Murphy's current disclosures

Revisions:

7 times, by 4 contributors - see full revision history and disclosures

Sections:

Imaging Technology

Synonyms:

Automatic exposure control (AEC) is incorporated into radiographic and mammographic imaging systems. Its function automatically terminates exposure when a preset amount of radiation has been detected.

Automatic exposure control systems help to provide a consistent optical density/signal-to-noise ratio between images, regardless of patient-centric factors such as size and density.

Automatic exposure control systems also help to reduce 'dose creep' that can occur with inadvertent radiation overexposure by the technologist.

The first generation of automatic exposure control systems are phototimers, which are now largely superseded by ionization chambers.

In radiography, the automatic exposure control device is placed in front of the image receptor. In mammography, the automatic exposure control device is placed underneath the image receptor.

Related (though discrete) principles include automatic brightness control (ABC) in fluoroscopy and tube current modulation in CT.