Patient specific doses used to analyse the optimum dose delivery in bariumenema examinations

The exposure and geometrical data for 89 barium enema examination patients were recorded manually in five hospitals in Finland. From the recorded data , organ and primary exit doses as well as effective individual doses were c alculated for each patient using the ODS-60 program, which is capable of ad justing the calculation phantom according to a patient's size and sex. The mean (and standard deviation, SD) and median effective individual doses for the patients were 9.3 (5.7) and 6.8 mSv, respectively. Conversion function s from dose-area product to relevant organ doses and to effective individua l dose were presented as a function of patient sex and weight. Mean primary exit dose values were calculated for each exposure. These were used to com pare a theoretically justified exposure control (EC) function with the func tion of the automatic exposure (rate) control, AEC (AERC), at different hos pitals. According to the analysis of primary exit doses, the implementation Of the EC was far from optimum. With EC function proposed in this study th e SD of effective individual doses to patients could be lowered considerabl y.