Final answer:
The thickness of a body part affects scatter and contrast in x-ray images. Thicker materials absorb more x-rays and have lower contrast, while thinner materials have greater scattering and higher contrast.
Step-by-step explanation:
As the x-ray energy increases, the Compton effect becomes more important in the attenuation of the x-rays. The probability for attenuation of the x-rays depends on the density of the material and the thickness of the material. Thicker materials absorb more x-rays and result in less scattering, which leads to lower contrast in the image. On the other hand, thinner materials allow more x-rays to pass through, resulting in greater scattering and higher contrast in the image.