Question

Why does a High kVp lower contrast?

A) A higher kVp increases the penetration of X-rays, reducing image contrast.
B) High kVp causes scatter radiation, leading to decreased image contrast.
C) Higher kVp results in more absorbed X-rays, enhancing image contrast.
D) High kVp has no impact on image contrast; it improves resolution.

Answer 1

A high kVp increases X-ray penetration, resulting in a reduction of image contrast due to the Compton scattering effect.

Step-by-step explanation:

High kilovolt peak (kVp) values in X-ray imaging increase the penetration of X-rays through materials, which in turn reduces the contrast of the resulting image.

As the energy of X-ray photons increases, more materials are penetrated, and fewer differences between tissue densities are represented, leading to lower contrast images. Specifically, a higher kVp leads to an increased Compton effect, which involves scattering rather than absorption of X-rays; this scattering blurs the distinctions between different types of tissue or material, further reducing image contrast.

Therefore, the correct answer to why a high kVp lowers contrast is: A) A higher kVp increases the penetration of X-rays, reducing image contrast.