Avaliação da exposição do público e médica em um cenário típico de exames que utilizam equipamento móvel de raios X através do método Monte Carlo

• Autor(a) principal: Santos, Felipe Amorim
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/5302
• topic: Raios X; Radiação; Pessoal da área médica; Radiografia; Raios X - Avaliação de riscos de saúde; Exposição a raios X; Health risk assessment; Medical personnel; Radiation; Radiography; X-rays; X-rays; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA

Detriments caused by ionizing radiation are the reason of many studies in medical physics. Both in experimental and computational fields, many studies seek to limit the risks involved in the practice with ionizing radiation. Accordingly, the field of computational simulation seeks to create scenarios in the most realistic way in order to measure with the greatest precision the radiation doses deposited in organs and tissues of patients, workers and the public. In this study, we generated scenarios that simulate exams involving mobile radiography equipment in beds of clinics and hospital. Through a pair of computational phantons, these scenarios allow the calculation of effective dose values and the conversion coefficients for individuals from the public and pacient based on the physical quantity absorbed dose. One of the simulators were irradiated with the direct beam (patient) simulating examinations of thorax and abdomen, each one with two fields of irradiation. For each of these situations, the X rays spectra were varied from 60 to 80 keV. The other simulator was positioned by the side of the patient simulator (individual from the public) from different distances for the assessment of the effective dose generated by the scattered beam and the subsequent calculation of the conversion coefficients. Regarding the effective dose measured in the patient, we obtained the maximum increase between the irradiation fields of 53,1% for thorax examination with 80 kVp. For abdomen examination, we obtained a maximum increase between the fields of irradiation of 6,4% to the beam of 80 kVp. For the radiation doses in the individual from the public, coming from the scattered beam, the maximum percentage difference between the ideal field and the extrapolated field was 76,1% when the beam was positioned at 50 cm away from the patient in a abdomen exam with 60 kVp. For the pacient, the greatest risk of cancer was 43,46.10-6 mGy-1 for extrapolated field with 80 kVp for abdomen examinations. For the individuals from the public, positioned at 200 cm, the risk of cancer decreases 83,0%, when it was positioned at 50 cm. Finally, radiation doses evaluated for a typical scenario in a hospital or clinic that provides services through mobile X ray equipment allows the measurement of possible damages related to this practice, both for the patient as for the individual from the public.