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Digital Image Artifacts

Copyright W.E.Blevins 2008. Shadowing

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Digital Image Artifacts

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    1. Copyright W.E.Blevins 2008 Digital Image Artifacts William E. Blevins, DVM, MS James K. Waldsmith, DVM J. Anthony Seibert, BS, BA, MS PhD.

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    8. Copyright W.E.Blevins 2008 Operating outside of Temperature Range When the TFT arrays are exposed to temperatures outside of normal operating range they begin to fail randomly producing linear artifacts. Some Amorphous Silicon panels have a temperature correction process which can be used to eliminate or improve the artifact effect. Amorphous Selenium panels do not have temperature correction and will permanently fail if operated outside of temperature range. Occasionally a similar artifact will appear associated with panel temperature changes and corrupted panel firmware.

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    11. Copyright W.E.Blevins 2008 Correction Files not applied to the image

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    20. Copyright W.E.Blevins 2008 This is an artifactual saturation of the signal through the lung area caused by the kVp being set too low, which causes the histogram to extend to lower and higher values overall. Those areas under the lung will transmit a considerably larger number of x-rays through the low attenuation lung area relative to the soft tissue areas. Using a higher kVp will reduce the relative attenuation differences of the lung versus soft tissue areas (lower subject contrast), which allows the anatomy to be properly presented in the image when applying contrast enhancement.This is an artifactual saturation of the signal through the lung area caused by the kVp being set too low, which causes the histogram to extend to lower and higher values overall. Those areas under the lung will transmit a considerably larger number of x-rays through the low attenuation lung area relative to the soft tissue areas. Using a higher kVp will reduce the relative attenuation differences of the lung versus soft tissue areas (lower subject contrast), which allows the anatomy to be properly presented in the image when applying contrast enhancement.

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    22. Copyright W.E.Blevins 2008 This is a combination of high Pass filter and high plate exposure. The high-pass filter artifactual appearance in highly exposed, uniform areas, which tend to solarize the output results.

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