What does kVp stand for and what does it primarily control?

• A. Kilovoltage peak; it controls beam quality and penetration
• B. Kilovolt peak; it controls exposure time
• C. Kiloamperes peak; it controls spatial resolution
• D. Kilovolt peak; it controls receptor exposure

Answer: (A)

Kilovoltage peak stands for kilovoltage peak, and it mainly controls beam quality and penetration. The voltage across the X-ray tube sets the energy of the produced photons: higher kVp means more energetic photons that penetrate tissue more easily, which lowers image contrast but allows imaging of thicker or denser anatomy. Exposure time and mA determine how many photons are produced (receptor exposure), not how energetic they are. The “peak” indicates the maximum voltage during the exposure, not a duration. So the best answer highlights kilovoltage peak and its effect on beam quality and penetration. The other options misstate what kVp controls (exposure time, spatial resolution) or use the wrong term.