Which statement best describes the effect of using high kVp on the radiographic exposure?

• A. Increases the exposure time
• B. Increases heat in the x-ray tube
• C. No change in exposure factors
• D. Reduces patient skin entrance dose

Answer: (D)

Raising kVp makes the x-ray beam more penetrating, so the same image brightness can be achieved with a lower number of photons reaching the patient. To keep the image receptor exposure consistent, you reduce the mAs (either by lowering the tube current or shortening the exposure time). Fewer photons depositing energy in the skin means the patient skin entrance dose decreases. Exposure time and tube heat are largely determined by mA and mAs, not by kVp, so simply increasing kVp doesn’t inherently increase exposure time or the tube’s heat load. That’s why this option—reducing the skin entrance dose when technique is adjusted upward in kVp—is the best description.