X-ray artifacts

Last revised by Mohammadtaghi Niknejad on 18 Mar 2024

X-ray artifacts can present in a variety of ways including abnormal shadows noted on a radiograph or degraded image quality, and have been produced by artificial means from hardware failure, operator error and software (post-processing) artifacts. 

There are common and distinct artifacts for film, computed (CR) and direct digital radiography (DR).

  • motion artifact

    • due to patient movement resulting in a distorted image

  • radiopaque objects on/external to the patient (e.g. jewelry (e.g. necklaces, piercings), clothing (e.g. buttons), hair (e.g. ponytail, hair braids etc.)

  • image compositing (or twin/double exposure)

    • superimposition of two structures from different locations due to double exposure of same film/plate

    • only in film and computed radiography

    • similar appearance to detector lag/ ghosting artifact in direct digital radiography (see below)

  • grid cut-off

  • debris in the housing 4 

    • debris in the housing caused by the collimator tube can cause small trapezoidal regions, indicative of lead shavings

  • finger marks

    • improper handling with hands

  • clear film

    • malfunction of the machine or placing the film in the fixer before developer solution

  • static electricity

    • black “lightning” marks resulting from films forcibly unwrapped or excessive flexing of the film

  • crescent-shaped black lines

    • due to fingernail pressure on the film

  • crescent-shaped white lines

    • due to cracked intensifying screen

  • black film

    • complete exposure to light.

  • clear spots

    • air bubbles sticking to film during processing

    • fixer splashed on film prior to developing

    • dirt on the intensifying screen

  • stitching artifacts

    • occur when two separate CR or DR images are merged into a single image (case 3)

  • over exposure

  • incorrect detector orientation i.e. upside-down cassette

    • spoke like radiopaque lines (case 6)

  • detector image lag or ghosting

    • latent image from previous exposure present on current exposure

  • backscatter

    • electronics are visible on the exposed image

    • increased radiation exposure required for portable DR (digital radiography) examinations

  • dead pixel artifact

  • signal dropout 4

    • large areas of signal loss, due to detector drop

  • speckled radiopaque spots 4

    • due to detector drop

  • detector calibration limitation 4

    • faint radiopaque striping (often vertical) in the background of an image, yet not evident on the anatomy 

    • this artifact should be carefully examined, if it does not interfere with the anatomy, it is not a detector failure/grid cut off, rather a limitation of the detector calibration

    • often seen as lower exposure

  • failure of detector offset correction 4

    • similar to ghosting, however, the digital detector not being calibrated when promoted is the cause 

  • electronic shutter failure 4

    • the digital image often will have obscurely shaped, tight collimation that defies logic

    • often a computer error often fixed with recollimation post exam (this should be explored before re-examination)

  • values of interest misread 4

    • image appears washed out and underexposed

    • this is often due to a largely collimated area of smaller anatomy i.e. a patella protection 

    • tighter digital collimation in conjunction with reprocessing will correctly assign the correct values of interest

  • mid grey clipping 4

    • loss of contrast in areas of different pixel density yet not change in density can be seen i.e. the metal on a knee replacement 

    • due to poor contrast enhancement

  • grid-line suppression failure 4​​

    • faint grid lines present on an image, with no grid cut off

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