Measurement of conversion coefficients between free in air kerma and personal dose equivalent for diagnostic X-ray beams

Rosado, P H G; Nogueira, Maria do Socorro; Genezini, Frederico A.; Vilela, E.

doi:10.1016/j.radmeas.2007.11.082

Cited by 10 publications

(8 citation statements)

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“…The experimental arrangement used followed the same irradiation and spectra geometry proposed by Rosado [15]. The values found in the simulation showed a relative difference of up to 0.16 for the backscatter factors and up to 0.33 for the conversion coefficients compared with the study proposed by Rosado [15], as shown in Tables 4.4 and 4.5 respectively. This difference is justified due to the static fluctuations and the approximations made in the modeling.…”

Section: Modeling Conversion Coefficients and Backscatter Factorsmentioning

confidence: 82%

“…The calculation of the backscatter factors and the conversion coefficients for the personal dose equivalent of diagnostic X-ray beams will be developed, in the RQR and RQA qualities established by IEC standards using the MCNP code and the male voxel anthropomorphic simulators (REX) and female (REGINA) of ICRP 110 [11] were derived from existing voxel models GOLEM and LAURA [12,13]. To achieve the objective, the following procedures were adopted: d) The average energy values of the X-ray beam spectra obtained experimentally by Rosado [15] were used;…”

Section: Methodsmentioning

confidence: 99%

“…Average energies of the beams of the RQR and RQA qualities determined by Rosado [15] were used as shown in Table 2. To calculate backscatter factors and conversion coefficients, the X-ray beams were directed in a solid angle cone, making the area irradiated in the cubic phantom of PMMA equivalent to the area irradiated according to the experimental arrangement used by Rosado [15]. The command "tally F6" from the MCNPX code was used to obtain the energy deposited in the points 10 mm deep on the phantom surface and on its surface.…”

Section: Problem Modeling and Radiation Spectramentioning

confidence: 99%

“…The adjustment of the points for the calculation of the mass absorption coefficient for PMMA as a function of energy can be obtained by Equations 1 and 2 [15]: (µ 𝑒𝑛 /ρ) = 0,01277 + 6,27556e -(E/6,38154) + 0,03226e -(E/66,87618)…”

Section: Average Energies and Mass Absorption Coefficientsmentioning

confidence: 99%

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Calculations of backpatch factors and conversion coefficients for the personal dose equivalent for X-ray beams used in radiodiagnostic

Moraes,

Madeira,

Coutinho

et al. 2024

Braz. J. Hea. Rev.

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The purpose of this study is to use the Monte Carlo N-Particle radiation transport code (MCNP) to calculate the conversion coefficients of air kerma for personal dose equivalent (Hp [Sv]) and Back Scattering Factors (BSF) for X-ray beams used in diagnostic radiography at potentials of 40, 50, 60, 70, 80, 90, 100, 120, and 150 kVp. Additionally, effective dose is determined using male and female anthropomorphic voxel-based simulators (REX and REGINA) as recommended by the International Commission on Radiological Protection (ICRP) Publication 110, along with tissue weight factors from ICRP Publication 103 to simulate whole-body irradiation. The results indicate that the relationship between operational metrics such as Hp and risk limitation metrics like effective dose varies from 0.14 to 0.71 for Radiation Qualities in Radiation (RQR) beams from the X-ray source assembly and up to 0.64 for Radiation Qualities based on a phantom with an added aluminium filter (RQA). When comparing the obtained values for air kerma conversion coefficients for personal dose equivalent with the value adopted by the National Commission for Nuclear Energy (CNEN) of 1.14 Sv/Gy for individual dose determination, it is observed that at low energies, the values are overestimated by up to 44%, while at high energies, the values are underestimated by up to 67%.

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Section: Modeling Conversion Coefficients and Backscatter Factorsmentioning

confidence: 82%

Section: Methodsmentioning

confidence: 99%

Section: Problem Modeling and Radiation Spectramentioning

confidence: 99%

Section: Average Energies and Mass Absorption Coefficientsmentioning

confidence: 99%

See 2 more Smart Citations

Calculations of backpatch factors and conversion coefficients for the personal dose equivalent for X-ray beams used in radiodiagnostic

Moraes,

Madeira,

Coutinho

et al. 2024

Braz. J. Hea. Rev.

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“…It was assumed that an operator in a radiologist makes operating room and ward exposures per year with the Nomad (50 exposures per day, 5 days per week, 50 weeks per year). Using the conversion factor from Gy to Sv (1.14 SvGy -1 ) [25]. Table 1 lists the simulation results of scattered radiation doses absorbed by a radiologist without a shield of lead clothing within a range of 2 m. During the experiments, the technician was exposed to 12 PX examinations on the chest, 5 PX examinations on the abdomen, 3 PX examinations on the pelvis, 8 PX examinations on the lumbar vertebrae, and C-arm perspective PX examination for 1 minute in the operating room.…”

Section: Discussionmentioning

confidence: 99%

Scattered radiation doses absorbed by technicians at different distances from X-ray exposure: Experiments on prosthesis

Chiang

Liu

Chen

et al. 2015

BME

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Abstract. This work aimed to investigate the spatial distribution of scattered radiation doses induced by exposure to the portable X-ray, the C-arm machine, and to simulate the radiologist without a shield of lead clothing, radiation doses absorbed by medical staff at 2 m from the central exposure point. Material and method: With the adoption of the Rando Phantom, several frequently X-rayed body parts were exposed to X-ray radiation, and the scattered radiation doses were measured by ionization chamber dosimeters at various angles from the patient. Assuming that the central point of the X-ray was located at the belly button, five detection points were distributed in the operation room at 1 m above the ground and 1-2 m from the central point horizontally. Results: The radiation dose measured at point B was the lowest, and the scattered radiation dose absorbed by the prosthesis from the X-ray's vertical projection was 0.07 ±0.03 μGy, which was less than the background radiation levels. The Fluke biomedical model 660-5DE (400 cc) and 660-3DE (4 cc) ion chambers were used to detect air dose at a distance of approximately two meters from the central point. The AP projection radiation doses at point B was the lowest (0.07±0.03 μGy) and the radiation doses at point D was the highest (0.26±0.08 μGy) .Only taking the vertical projection into account, the radiation doses at point B was the lowest (0.52 μGy), and the radiation doses at point E was the highest (4 μGy).The PA projection radiation at point B was the lowest (0.36 μGy) and the radiation doses at point E was the highest(2.77 μGy), occupying 10-32% of the maximum doses. The maximum dose in five directions was nine times to the minimum dose. When the PX and the C-arm machine were used, the radiation doses at a distance of 2 m were attenuated to the background radiation level. The radiologist without a lead shield should stand at point B of patient's feet. Accordingly, teaching materials on radiation safety for radiological interns and clinical technicians were formulated.

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A simple analytical expression to calculate the backscatter factor for low energy X-ray beams

Chica

Flórez²,

Anguiano

et al. 2011

Physica Medica

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Measurement of conversion coefficients between free in air kerma and personal dose equivalent for diagnostic X-ray beams

Cited by 10 publications

References 1 publication

Calculations of backpatch factors and conversion coefficients for the personal dose equivalent for X-ray beams used in radiodiagnostic

Calculations of backpatch factors and conversion coefficients for the personal dose equivalent for X-ray beams used in radiodiagnostic

Scattered radiation doses absorbed by technicians at different distances from X-ray exposure: Experiments on prosthesis

A simple analytical expression to calculate the backscatter factor for low energy X-ray beams

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