What kind of x-ray interaction involves a complete transfer of energy?

The interaction that involves a complete transfer of energy is photoelectric absorption. In this process, an incoming photon completely transfers its energy to an inner-shell electron of an atom, leading to the ejection of that electron from its orbit. This total energy transfer results in the photon being completely absorbed, thus ceasing to exist, while the ejected electron is referred to as a photoelectron.

Photoelectric absorption is significant in diagnostic imaging because it primarily occurs in materials with high atomic numbers, such as bone, resulting in greater contrast on radiographic images. This interaction is crucial for understanding how x-rays are absorbed by different tissues and how this contributes to the imaging process.

While coherent scatter, the Compton effect, and Rayleigh scatter represent other interactions that can occur between x-rays and matter, they do not involve a total transfer of energy. In coherent scatter, photons are scattered without energy loss, while in Compton scattering, only part of the energy is transferred to an outer-shell electron, and some energy remains with the scattered photon. Rayleigh scatter involves the elastic scattering of photons without any change in energy. Understanding the distinctions among these interactions is essential for imaging professionals and impacts how different materials are visualized on x-rays.