Time for unification of CT dosimetry with radiography and fluoroscopy

The air kerma-area product can be used to quantify the total amount of radiation that is incident on the patient. Measured or calculated values of KAP in CT may be used as a relative indicator of the patient risk or converted into a corresponding value of the effective dose. Adoption of KAP in CT as a measure of the amount of radiation a patient receives will make CT dosimetry consistent with current practice in radiography, fluoroscopy and special procedures. The inability of CTDI to deal with increasingly wide X-ray beams in CT makes this an opportune time to seriously consider replacing CTDI with KAP to quantify the 'amount' of radiation used to perform any given CT examination. (authors)