X-ray photon absorption

X-ray photon absorption refers to the process by which X-ray photons interact with matter, primarily through the photoelectric effect at lower energies and Compton scattering at higher energies[6][9][11]. In the photoelectric effect, the full energy of the X-ray photon is transferred to an inner-shell electron, which is ejected, ionizing the atom and creating a vacancy that is filled by electrons from higher energy levels, releasing characteristic X-rays or Auger electrons in turn[6][9][11]. This process underpins how X-rays deposit energy in tissues, creating biological effects (such as DNA damage) and enabling contrast in X-ray imaging[6][9][1][11]. The absorption is highly dependent on the atomic number of the absorbing material (greater for bone than soft tissue) and the photon energy. The process is essential in both diagnostic radiology (for creating images based on relative absorption in different tissues) and in radiation therapy (where absorption leads to therapeutic or damaging biological effects)[1][6][9][11]. However, "X-ray photon absorption" is not a molecular target for therapeutic intervention.

Other names

X-ray absorptionphotoelectric effect (in context)X-ray attenuation (related, but not identical)

Not applicable for drugs (contrast agents like iodine enhance X-ray absorption for better imaging contrast, but absorption is a physical property, not a druggable site)