What is the predominant type of radiation interaction occurring in diagnostic radiology?

In diagnostic radiology, the predominant type of radiation interaction is Compton scattering. This process involves the interaction of X-ray photons with matter, specifically with loosely bound outer shell electrons. During this interaction, a portion of the X-ray photon’s energy is transferred to the electron, allowing it to be ejected from its orbit. The photon continues on a trajectory at a reduced energy level, resulting in the scatter of the photon.

Compton scattering is significant in diagnostic imaging because it occurs at the energies typically used in this field, which range from about 30 keV to several hundred keV. The scattered photons contribute to the image formation but also create noise and can degrade image quality. Understanding this interaction helps radiologic technologists and radiologists manage exposure and optimize imaging techniques.

In contrast, while the photoelectric effect can also play a role, especially in scenarios with high atomic number tissues, it is less common overall in most diagnostic imaging situations compared to Compton scattering. Other interactions like pair production and Rayleigh scattering are generally not significant under the energy levels typical for diagnostic radiology; pair production requires much higher energy photons, and Rayleigh scattering does not contribute directly to imaging contrast. Thus, Compton scattering is recognized as the primary interaction that influences