Assuming that no other exposure variables change, how does an increased kilovoltage peak (kVp) affect the proportion of scatter radiation striking the image receptor?

An increased kilovoltage peak (kVp) leads to an increase in the energy of the X-ray photons produced during imaging. This higher energy not only enhances the overall penetration of the X-rays through the patient but also increases the likelihood that these photons will interact with tissues in a manner that generates scatter radiation.

When the kVp is raised, the distribution of X-ray photon energies also shifts higher, and as a consequence, more photons are able to pass through the patient's tissues without being absorbed. However, higher-energy photons can still undergo Compton scattering, which is a primary mechanism of scatter radiation production. Consequently, with an elevation in kVp, while some photons pass directly through, more of them interact with tissues, resulting in an increase in the amount of scatter radiation that reaches the image receptor.

This phenomenon underscores the relationship between higher kVp values and the propensity for scatter radiation; thus, an increased kVp correlates directly with increased scatter radiation striking the image receptor.