X-ray attenuation by iodine

X-ray attenuation by iodine is a physical phenomenon central to radiological imaging diagnostics, based on iodine's high atomic number (Z=53) and specific K-edge (33.2 keV). When X-rays of appropriate energy interact with iodine, the probability of photoelectric absorption increases sharply, resulting in enhanced local absorption (attenuation) of X-ray photons. This property is harnessed in iodinated contrast media to improve tissue contrast in imaging modalities like CT. The process is not a drug or molecular target, but a physical principle underlying the use of iodine compounds in clinical imaging agents. Though not a biological target, the process carries important safety considerations—including increased DNA damage and radiation dose to tissues exposed to iodinated contrast agents, potentially raising cancer risks[2][3][7].

Other names

Iodine K-edge attenuationIodinated contrast mediaIodine-based CT contrast

Photoelectric effect (Iodine atoms absorb X-ray photons at energies near their K-shell binding energy, resulting in increased local attenuation and image contrast)[3][4][5][7]