What is the effect of increasing kilovoltage on the image's contrast scale?

What is the effect of increasing kilovoltage on the image's contrast scale?

• A. Increases sharpness
• B. Produces a longer scale of contrast
• C. Decreases patient dose
• D. Decreases exposure latitude

Answer: (B)

Raising kilovoltage increases the energy of the X-ray photons, so the beam is more penetrating. Because of this, differences in attenuation between tissues become less pronounced, producing more gray tones on the image. That creates a longer scale of contrast—more shades between black and white, i.e., lower inherent contrast. The other effects described aren’t about the contrast scale: sharpness is mainly affected by factors like focal spot size and motion, not kilovoltage; while higher kVp can influence dose in practice, the question focuses on the image’s contrast scale; and exposure latitude actually tends to increase with higher kVp, not decrease.

Raising kilovoltage increases the energy of the X-ray photons, so the beam is more penetrating. Because of this, differences in attenuation between tissues become less pronounced, producing more gray tones on the image. That creates a longer scale of contrast—more shades between black and white, i.e., lower inherent contrast. The other effects described aren’t about the contrast scale: sharpness is mainly affected by factors like focal spot size and motion, not kilovoltage; while higher kVp can influence dose in practice, the question focuses on the image’s contrast scale; and exposure latitude actually tends to increase with higher kVp, not decrease.