Use of the concept of energy imparted in diagnostic radiology

The concept of energy imparted by ionizing radiation to the matter in a volume is analyzed and methods to determine the energy imparted var epsilon to the patient are reviewed, in particular, determinations based on measurements of the air kerma integrated over beam area [the kerma-area-product (KAP)] and calculations needed to derive conversion factors var epsilon/KAP. The energy imparted to the image receptor, var epsilonrec, including the statistical aspects of the concept, and the effect of var epsilonrec on image quality and patient dose are also analysed. Finally, use of the energy imparted to the patient as a risk indicator is discussed.