What is the terminology for radiation dose?
Absorbed dose, equivalent dose, and effective dose are all used to describe the effects of radiation on tissue. Absorbed dose specifically refers to the energy transferred to a quantity of tissue by ionizing radiation. Equivalent dose can be derived from absorbed dose by applying a weighting factor that describes the type of radiation, in order to account for the different biological effects of different types of radiation. X-rays, gamma rays, and beta particles, some types of radiation used in medical imaging, are assigned a weighting factor of 1.
Effective dose is the weighted sum of the equivalent doses for all the tissues of the body. The tissue weighting factors are determined by the International Commission on Radiological Protection (ICRP) and periodically updated. ICRP Publication 103 was the most recent update of the tissue weighting factors, which was released in 2007  . Effective dose is meant to confer an estimate of risk of adverse effects due to exposure to ionizing radiation; it does not describe the actual amount of radiation imparted to or absorbed by the body.