History of radiation exposure of the chest

Measure of ionization of air by ionizing radiation

For other uses, see Radiation exposure (disambiguation).

Radiation exposure is a measure of the ionization of air due to ionizing radiation from photons.^[1] It is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air.^[1] As of 2007, "medical radiation exposure" was defined by the International Commission on Radiological Protection as exposure incurred by people as part of their own medical or dental diagnosis or treatment; by persons, other than those occupationally exposed, knowingly, while voluntarily helping in the support and comfort of patients; and by volunteers in a programme of biomedical research involving their exposure.^[2] Common medical tests and treatments involving radiation include X-rays, CT scans, mammography, lung ventilation and perfusion scans, bone scans, cardiac perfusion scan, angiography, ra