A technologist is using a variable kilovoltage peak (kVp) chart to set the exposure technique for a table-top radiograph. If the technique chart calls for 76 kVp but the technologist uses 140 kVp, the resulting image will likely demonstrate which of the following?

A technologist is using a variable kilovoltage peak (kVp) chart to set the exposure technique for a table-top radiograph. If the technique chart calls for 76 kVp but the technologist uses 140 kVp, the resulting image will likely demonstrate which of the following?

• A. Saturation artifact
• B. Quantum mottle
• C. Increased contrast
• D. No visible errors

Answer: (A)

Pushing kilovoltage peak far beyond what the exposure technique chart prescribes causes the beam to be so penetrating that the digital detector can be driven into its maximum response in dense areas. When the receptor’s signal is driven beyond its usable range, those areas clip and appear pure white, with loss of detail—this is the saturation artifact. The image ends up overexposed in parts, which is the hallmark of this scenario. Quantum mottle results from too few photons and appears as graininess, which isn’t what happens when you dramatically raise kVp. Increased contrast would occur with lower kVp, not with a setting that’s far too high. No visible errors would be incorrect because the excessive exposure typically produces a clearly flawed image due to clipping.

Pushing kilovoltage peak far beyond what the exposure technique chart prescribes causes the beam to be so penetrating that the digital detector can be driven into its maximum response in dense areas. When the receptor’s signal is driven beyond its usable range, those areas clip and appear pure white, with loss of detail—this is the saturation artifact. The image ends up overexposed in parts, which is the hallmark of this scenario.

Quantum mottle results from too few photons and appears as graininess, which isn’t what happens when you dramatically raise kVp. Increased contrast would occur with lower kVp, not with a setting that’s far too high. No visible errors would be incorrect because the excessive exposure typically produces a clearly flawed image due to clipping.