Avaliação dosimétrica de um dispositivo utilizando o código MCNPX em tomografia computadorizada

• Autor(a) principal: Vasconcelos, Ejakson José de Sousa
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/40388
• topic: MCNPX; Método de Monte Carlo; Tomografia computacional

Computed tomography (CT) is a diagnostic test that provides a high dose of radiation to the patient. In this context, works involving CT dosimetry are very relevant to minimize possible biological effects of radiation. In this work, we sought to validate a computational model using experimental data collected on a Asteion VR model from Toshiba. The Monte Carlo code statistical method was applied using the MCNPX package for the calculation of the radiation dose in a semiconductor photodiode detector. In order to perform the computational simulation, a CT room, the tomograph and a pencil type detector containing a photodiode element were constructed. The simulated data contain the same dimensions and radiation parameters used experimentally. We place the photodiode in different positions of the gantry in order to obtain the dose profile. As expected, a higher incidence of radiation was observed when the detector was centralized with the X-ray beam. Continuing the work, a dose profile analysis was also carried out in certain positions, where it will be important for the result obtained. Finally, the sensitivity of the photodiode was analyzed, exposing it to the determined voltages, where there was a decrease in sensitivity due to the interaction of photons with the material. According to the results obtained, this model is able to simulate a tomographic examination, as it performs dose detection throughout the radiated body and is compatible with the experimental results, contributing to minimize the harmful effects of RX radiation.