Which parameter directly controls the energy (quality) of the X-ray beam?

Which parameter directly controls the energy (quality) of the X-ray beam?

• A. Distance
• B. kVp
• C. mA
• D. Filtration

Answer: (B)

Energy (beam quality) is determined by the peak kilovoltage. Increasing kVp raises the maximum energy of the emitted photons and shifts the spectrum toward higher-energy, more penetrating photons. Distance and tube current mainly affect how many photons reach the image receptor (intensity) rather than their energy. Filtration can modify the spectrum by removing low-energy photons, which raises the mean energy somewhat, but the primary factor that sets the energy scale of the beam is the kilovoltage.

Energy (beam quality) is determined by the peak kilovoltage. Increasing kVp raises the maximum energy of the emitted photons and shifts the spectrum toward higher-energy, more penetrating photons. Distance and tube current mainly affect how many photons reach the image receptor (intensity) rather than their energy. Filtration can modify the spectrum by removing low-energy photons, which raises the mean energy somewhat, but the primary factor that sets the energy scale of the beam is the kilovoltage.