An x-ray exposure above the highest level of the exposure latitude may result in an error called:

• A. Saturation artifact
• B. Quantum mottle
• C. Excessive contrast
• D. Geometric distortion

Answer: (A)

Exposure latitude is the range of exposures a detector can accurately reproduce. When the exposure goes above the highest level of that latitude, the detector’s response is maxed out and cannot distinguish any more brightness in the overexposed areas. This clipping of signal in the bright regions creates a saturation artifact, where details are lost and those areas appear uniformly white or have no diagnostic information.

Quantum mottle happens when there aren’t enough photons reaching the detector, leading to a grainy or mottled appearance. Excessive contrast arises from too great a difference between adjacent grayscale values, not from overexposure itself. Geometric distortion stems from improper alignment or geometry, such as object-to-image distance or angulation, and is not caused by exposure level.