진단 방사선영역에서의 선량 계측

Dosimetry in diagnostic radiologic examination

？？In this study, we propose a method to determine the integral dose to patients undergoing any diagnostic x-ray examination using the concept of energy imparted to the patient, ？. ？？Energy imparted is a measure of the total ionizing energy deposited in the patient during a radiologic examination and may be used to quantify the patient dose in diagnostic radiology. The patient effective dose, E, is an indicator of the stochastic radiation risk associated with radiographic or fluoroscopic x-ray examinations. Determining effective doses for radiologic examinations by measurement or calculation is generally very difficult. By contrast, the energy imparted, ？, to the patient may be obtained from the x-ray exposure-area product incident on the patient. ？？As energy imparted exponentially decreased with the depth dose ratio, we measure the depth dose ratio for the tube spectra with peak x-ray tube voltages ranging from 40-120 ㎸p. ？？The energy imparted, ？, to the patient may be calculated by equation, ？ ？= DoㆍρㆍA？ㆍ(1 - e<SUP>-αx</SUP>)( (F + x ) /F)²ㆍx. ？？Fitted exponential graph with depth dose ratio are provided that permit the energy imparted to be determined for any combination of tube voltage and phantom thickness from the product of the entrance skin dose and the corresponding x-ray beam area.