RESUMEN
INTRODUCTION: The aim of this study was to experimentally measure organ doses for computed tomography (CT) procedures using thermoluminescence dosimeters (TLDs) on a RANDO anthropomorphic phantom and verify the measured doses using CT-Expo software. METHODS: The phantom was irradiated using clinical CT scan protocols routinely used for specific procedures in the radiology department. Fifty TLD chips were used in this study. The scanning parameters (kVp, mA, s) used to scan the phantom were used as input parameters for CT-Expo dose estimations. RESULTS: The TLD measured organ doses varied between 3.97 mGy for the esophagus and 56.22 mGy for the brain. High doses were recorded in the brain (37.80-56.22 mGy) and the eye lens (29.94-36.16 mGy). Comparing the organ dose measurements between TLD and CT-Expo, the maximum organ dose difference was obtained for the eye lens. A comparison between the two methods for the other organs were all less than 32 %. The effective doses from the TLD measurements for the head, chest, and abdominopelvic CT examinations were 2.78, 6.67, and 17 mSv, respectively and CT-Expo were 2.20, 10.30, and 16.70 mSv, respectively. CONCLUSION: The experimental and computational results are comparable, and the reliability of the TLD measurements and CT-Expo dose calculator has been proven. IMPLICATIONS FOR STUDY: A reason for the difference in dose measurements between the two methods has been attributed to the dissimilarity in the organ position in the Rando anthropomorphic phantom and the standard mathematical phantom used by CT-Expo. The experimental and computational results have been found to be comparable.
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Programas Informáticos , Tomografía Computarizada por Rayos X , Humanos , Dosis de Radiación , Reproducibilidad de los Resultados , Tomografía Computarizada por Rayos X/métodos , TóraxRESUMEN
Preliminary studies on effective and eye lens doses of six Radiologists, four Cardiologists have been conducted for a period of 3 months. Electronic dosemeters positioned under and over lead apron of staff were used for the dosimetry. The estimated effective dose per month to Cardiologist and Radiologist were 0.01-0.07 mSv and 0.03-0.14 mSv, respectively. The estimated eye lens doses per month to Cardiologists and Radiologists were also 0.15-0.30 mSv and 0.53-3.39 mSv, respectively. The effective doses per month to staff were below the ICRP acceptable limit of 1.67 mSv/month but the upper limit of the range of estimated eye lens dose exceeded the ICRP acceptable limit by a factor of 2. Regular use of protective goggles and consistent eye lens dose monitoring is encouraged at the hospital for dose optimization.
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Fluoroscopía/métodos , Cristalino/efectos de la radiación , Exposición Profesional/análisis , Personal de Hospital/estadística & datos numéricos , Exposición a la Radiación/análisis , Protección Radiológica/normas , Radiometría/métodos , Cardiología/normas , Dispositivos de Protección de los Ojos , Hospitales de Enseñanza , Humanos , Ropa de Protección/normas , Dosis de Radiación , Radiología/normasRESUMEN
Studies have shown that there is high radiation exposure to medical staff during computed tomography fluoroscopy (CTF)-guided procedures. This study aims to investigate staff dose reduction techniques considering the CTF gantry positioning in the room and room dimensions in addition to the conventional use of thyroid collars, aprons and eye goggles. A Toshiba Aquilion One 640 slice CT scanner and CTF room were modelled using SimpleGeo. Standing and supine adult mesh phantoms were used to represent the staff and patient. The models were spatially put together on one platform using VOXEL2MCNP. Based on this, MCNPX input files were generated for the studies. CTF gantry and staff positions, and CTF room size were varied for different scenarios. Effective, eye lens and thyroid dose to staff were estimated for each scenario. Additional means of possible dose reduction with respect to positioning of the CTF device and room layout are discussed.
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Fluoroscopía/métodos , Exposición Profesional/análisis , Exposición Profesional/prevención & control , Monitoreo de Radiación/métodos , Protección Radiológica/métodos , Dispersión de Radiación , Tomografía Computarizada por Rayos X/métodos , Adulto , Dispositivos de Protección de los Ojos , Humanos , Imagenología Tridimensional , Cristalino/efectos de la radiación , Método de Montecarlo , Posicionamiento del Paciente , Fantasmas de Imagen , Ropa de Protección , Dosis de Radiación , Posición Supina , Glándula Tiroides/efectos de la radiación , Tomógrafos Computarizados por Rayos XRESUMEN
The safety culture of selected practices and facilities in Ghana utilising radiation sources or radiation emitting devices has been assessed using a performance indicator, which provided status information on management and operating staff commitment to safety. The questionnaire was based on the following broad areas: general safety considerations, safety policy at the facility level, safety practices at the facility level, definition of responsibility, staff training, safety of the physical structure of the facility and the emergency plans. The analysis showed that the percentage levels of commitment to safety for the respective practices are as follows: conventional radiography, 23.3-90.0%; research reactor, 73.3%; gamma irradiation facility, 53.3%; radiotherapy, 76.7%; X-ray scanner, 80.0%; gamma scanner, 76.7%; industrial radiography 86.7% and nuclear density practice, 78%. None of the practices or facilities was able to satisfy all the requirements that will ensure a 100% level of safety culture.
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Protección Radiológica/normas , Radiación Ionizante , Liberación de Radiactividad Peligrosa/prevención & control , Servicio de Radiología en Hospital/normas , Administración de la Seguridad , Cultura , Ghana , Humanos , Encuestas y CuestionariosRESUMEN
Organ and effective doses to 90 patients undergoing some selected fluoroscopic examinations at the Korle-Bu Teaching Hospital were estimated using the Monte Carlo-based program (PCXMC version 1.5). Radiation dose was estimated from free-in-air measurements. The mean effective doses were found to be 0.29 +/- 0.07, 0.84 +/- 0.13, 3.15 +/- 0.44, 6.24 +/- 0.70 and 0.38 +/- 0.05 mSv for urethrogram, barium swallow, barium meal, barium enema and myelogram examinations, respectively. The dose area product was estimated to be 3.55 +/- 0.95, 16.44 +/- 2.60, 50.81 +/- 7.04, 99.69 +/- 10.85 and 9.32 +/- 0.99 Gy cm(2) for urethrogram, barium swallow, barium meal, barium enema and myelogram examinations, respectively. Optimisation of procedures is required for barium enema and barium meal examinations.