Increased kilovoltage peak (kVp) affects differential attenuation of the x-ray beam by:

Increased kilovoltage peak (kVp) affects differential attenuation of the x-ray beam by:

• A. Increased differential attenuation
• B. Decreased differential attenuation
• C. kVp does not affect differential attenuation
• D. Differential attenuation varies with exposure

Answer: (B)

Raising kilovoltage peak increases the energy of the x-ray photons. When photons are more energetic, they are less likely to be absorbed differently by two tissues, so the contrast between them diminishes. At low kVp, the photoelectric effect dominates and depends strongly on tissue composition (like bone vs soft tissue), producing large differences in attenuation. As kVp goes up and Compton scattering becomes more common, attenuation differences between tissues become smaller, leading to decreased differential attenuation. That’s why higher kVp lowers the contrast between different tissues on the image.

Raising kilovoltage peak increases the energy of the x-ray photons. When photons are more energetic, they are less likely to be absorbed differently by two tissues, so the contrast between them diminishes. At low kVp, the photoelectric effect dominates and depends strongly on tissue composition (like bone vs soft tissue), producing large differences in attenuation. As kVp goes up and Compton scattering becomes more common, attenuation differences between tissues become smaller, leading to decreased differential attenuation. That’s why higher kVp lowers the contrast between different tissues on the image.