Patient doses in different projections of conventional diagnostic X-ray examinations

The entrance surface doses (ESDs) of six commonly performed diagnostic X-ray projections were surveyed in four public hospitals, and an experimental formula was derived for estimating the ESD from the exposure parameters of different projections. In-phantom measurements of the organ doses were also performed for the six projections, and the effective doses were evaluated using different sets of tissue weighting factors recommended by the International Commission on Radiological Protection (ICRP). For the chest radiograph, compared with the low tube potential technique, lower ESD was observed in the high tube potential technique; however, no significant difference of effective doses was found between the two techniques. Except for the pelvis radiography, the effective doses of five other projections evaluated with the tissue weighting factors (w(T)) recommended by ICRP publication 103 were generally higher than those evaluated with the factors recommended by ICRP publication 60.