Using high kVp results in which type of contrast and grayscale?

• A. High-contrast, few gray tones
• B. Short-scale, few gray tones
• C. Long-scale, many gray tones
• D. Low contrast, no gray tones

Answer: (C)

High kilovoltage raises the energy of the X-ray photons, making the beam more penetrating. This reduces the differences in attenuation between tissues on the image, which lowers subject contrast. With less contrast between structures, more gray shades appear across the image, producing a longer gray scale with many tones. So, high kVp yields long-scale contrast with many gray tones.