Effective dose conversion coefficients as a function of patient weight for routine X-ray examination

Abstract

   Based on the information regarding the parameters of routine radiographic procedures the values of the conversion coefficients to the effective dose in patients of different weights were calculated. The numerical values of the conversion coefficients correspond to the effective dose values during a given radiographic examination, which is completely determined by a set of technical, geometric, and dosimetric parameters normalized to the absorbed dose value in the air at a distance of 1 m from the tube focus (Ke, μSv/mGy)), or to the dose-area product value measured during the examination (Kd, μSv/(cGy cm2)). t is shown that the Ke factors have a greater relative spread of their values than the Kd factors. Within each weight group of patients, the Kd factor value for a patient of standard weight can be converted to the value for a patient of different weight. Furthermore, extrapolation of the calculated Kd values to infant weights well below 2.6 kg (down to 0.6 kg), i.e. for premature infants, yields satisfactory estimates of the Kd value.