A dosimetric study of occupational exposure during computed tomography procedures

The number of chest computed tomography (CT) procedures has increased worldwide as it is a diagnostic tool for a variety of lung diseases, mainly for visualizing and monitoring lung extensions and impairments. Due to respiratory problems in patients during the CT scan, health professionals need to perform special care such as BagValve-Mask Ventilation and accompany them throughout the procedure. Therefore, this study aimed to investigate and evaluate the doses received by these professionals during a chest CT study. The effectiveness of personal protective equipment (PPE) was also evaluated. To achieve these objectives, computational scenarios were simulated with pediatric (1 and 10 years old) and adult virtual anthropomorphic phantoms, representing patients and professionals. Conversion coefficients for equivalent (CC[HT]) and effective (CC([E]) doses were determined using the MCNP 6.2 Monte Carlo code. The results obtained showed that the highest dose effective [E] values were for the professional positioned in front of the gantry and without the use of PPE, ranging from around 5.78 x 10-2 to 1.82 x 10-1 mSv, depending on the patient size monitored during the examination and the x-ray tube voltage. The organs of the simulated professionals with the highest CC[HT] values were the breasts (female) and testicles (male). Furthermore, the use of PPE demonstrate reductions on CC[HT] and CC([E] values of the professional of approximately 91 %.