Increasing kVp generally has what effect on DQE?

• A. Decreases
• B. Increases
• C. No change
• D. Depends on exposure

Answer: (C)

DQE measures how well the detector preserves signal quality (SNR) across spatial frequencies as X-ray energy is converted into an image.

In the diagnostic kVp range, raising kVp shifts the X-ray spectrum to higher energies and reduces subject contrast, but modern digital detectors maintain their ability to convert incident energy into image signal with only minimal change. The balance of detector optics, electronics, and noise characteristics stays essentially the same, so DQE remains about the same. That’s why increasing kVp is viewed as having no meaningful change on DQE.

Other options imply a consistent drop or rise with kVp, or tie DQE to exposure level, which doesn’t align with how DQE is defined and how modern DR detectors behave across typical kVp values.