Investigation of Backscattered Dose in a Computerized Tomography (CT) Facility during Abdominal CT Scan by Considering Clinical Measurements and Application of Monte Carlo Method

Abstract

X-ray computed tomography (CT) related to computer-processed combination or X-ray images obtained from different angles to create patient's cross-sectional body parts images. CT ensures to have imaging various organs, bones, blood vessel etc. and more advantageous than normal plain X-ray devices in consequence of 360 degree image of internal organs, the spine and vertebrae. For decades, Radiation protection became a main topic in research areas since CT uses various dose of X-ray for imaging body. Distance factor is the one of fundamental principle of radiation protection. Maximum dose occurs around gantry and dose rate is decreases by distance in CT facilities. To know the rate of reduction of the amount of dose by distance is very significant for radiation protection procedure especially for apply criteria of International Commission on Radiological Protection (ICRP) on radiation protection. Our study aimed to measure scattered dose rates during abdominal CT scan by considering small distance ranges from gantry until exit door and comparing the empirical result with Monte Carlo (MC) calculations. As a next step of study, we modeled a simulation input for CT facility by using MCNP-X (version 2.4.0). We obtained the changes of dose rate on distance factor by using Monte Carlo method. We achieved that MCNP-X calculations were in concordance with clinical experimental measurements. It can be concluded that Monte Carlo (MC) is an effective tool for obtain dose rate variations around CT gantry and especially radiation protection calculations in CT facilities.