Evaluation of medical exposure and exposure by the public in a typical scenario of examinations using mobile X-ray equipment through the Monte Carlo simulation

Abstract

In this work irradiation scenarios that simulated chest and abdomen examinations involving mobile X-ray equipment in hospitals were modeled with the purpose of calculating conversion coefficient for effective dose (CCE), normalized to entrance surface dose (ESD), applied to patients and public individuals. These coefficients can easily be used in this practice. Patients and public individuals were represented by a pair of anthropomorphic phantoms inserted in the MCNPX 2.7.0 radiation transport code. One of the phantoms (patient) was irradiated with the direct beam simulating examinations of the chest and abdomen, each with two fields of irradiation, ideal (IF) and extrapolated (EF). Using the software SPECGEN X-ray spectra from 60 to 100 kVp at 10 kVp intervals were generated and used in this work. The other phantom (public individual) was positioned 50–200 cm from the patient. In relation to the CCE calculated in the patient, the average increase obtained between the irradiation fields was 62.4% for the chest examinations, and for the same conditions the CCE was calculated for abdomen examinations and found to be 8.0%. Increasing the distance between public individual and patient, reductions of up to 81.7% in the CCE in abdomen examinations and 83.4% in chest examinations were observed. Through the assessment of CCE of these scenarios, it is possible to measure the damages relating to this practice for both patients and public individuals.