Pub Date : 2021-12-29DOI: 10.14407/jrpr.2021.00178
Chanki Lee, H. Kim
Materials and Methods: Regarding this, we test and suggest a measurement technique for gross alpha/beta and 90Sr activities in surface soil based on a mobile ZnS(Ag)/PVT (polyvinyltoluene) array and a handheld PVT rod, respectively. To detect 90Sr selectively in soil mixed with naturally occurring radioactive materials, chosen energy channel counts from the multichannel analyzers were used instead of whole channel counts. Soil samples contaminated with exempt liquid 90Sr with 1 Bq· g-1, 3 Bq· g-1, and 10 Bq· g-1 were prepared and hardened by flocculation.
{"title":"Preliminary Study on Rapid Measurement of Gross Alpha/Beta and 90Sr Activities in Surface Soil by Mobile ZnS(Ag)/PTV Array and Handheld PVT Rod with Gated Energy Channels","authors":"Chanki Lee, H. Kim","doi":"10.14407/jrpr.2021.00178","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00178","url":null,"abstract":"Materials and Methods: Regarding this, we test and suggest a measurement technique for gross alpha/beta and 90Sr activities in surface soil based on a mobile ZnS(Ag)/PVT (polyvinyltoluene) array and a handheld PVT rod, respectively. To detect 90Sr selectively in soil mixed with naturally occurring radioactive materials, chosen energy channel counts from the multichannel analyzers were used instead of whole channel counts. Soil samples contaminated with exempt liquid 90Sr with 1 Bq· g-1, 3 Bq· g-1, and 10 Bq· g-1 were prepared and hardened by flocculation.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"8 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75407634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-29DOI: 10.14407/jrpr.2021.00164
K. Tagami, S. Uchida
Background: This study was carried out to provide environmental transfer parameter values to estimate activity concentrations of these radionuclides in agricultural crops when direct contamination occurred. Materials and Methods: Mass interception fractions ( F B s) and weathering half-lives ( T w s) of 131 I and radiocesium were calculated using openly available monitoring data obtained after the Fukushima Daiichi Nuclear Power Plant accident. F B is the ratio between the initial radioactivity concentration of a radionuclide retained by the edible part of the plant (Bq ‧ kg -1 fresh weight [FW]) and the amount of deposited radionuclide in that area (Bq ‧ m -2 ). T w values can be calculated using activity concentrations of crops decreased with time after the initial contamination. Results and Discussion: Calculated F B and T w values for 131 I and radiocesium were mostly obtained for leafy vegetables. The analytical results showed that there was no difference of F B s between 131 I and radiocesium by t -test; geometric mean values for leafy vegetables cultivated under outdoor conditions were 0.058 and 0.12 m 2 ‧ kg -1 FW, respectively. Geometric mean T w value of 131 I in leafy vegetables grown under outdoor conditions was 8.6 days, and that of radiocesium was 6.6 days; there was no significant difference between T w values of these radionuclides by Wilcoxon rank sum test. Conclusion: There was no difference between 131 I and radiocesium for F B s and T w s. By using these factors, we would be able to carry out a rough estimation of the activity concentrations of 131 I and radiocesium in the edible part of leafy crops when a nuclear accident occurred.
背景:本研究旨在提供环境转移参数值，以估计在直接污染发生时这些放射性核素在农作物中的活度浓度。材料和方法:利用福岛第一核电站事故后获得的公开监测数据，计算了131 I和放射性元素的质量拦截分数(F B s)和风化半衰期(T w s)。fb为植物可食用部分所保留的放射性核素的初始放射性浓度(Bq·kg -1鲜重[FW])与在该地区沉积的放射性核素量(Bq·kg -2)之比。tw值可以通过初始污染后随时间减少的作物活性浓度来计算。结果与讨论:131 I和放射性元素的F - B和T - w计算值主要来自叶菜。经t检验，结果表明:131i与放射性铯的F - B - s无显著性差异;室外栽培叶菜的几何平均值分别为0.058和0.12 m 2·kg -1 FW。室外条件下叶菜131 I的几何平均T w值为8.6 d，放射性铯的几何平均T w值为6.6 d;经Wilcoxon秩和检验，这些放射性核素的tw值之间无显著差异。结论:放射性元素131 I和放射性元素放射性元素在F B s和T w s中没有差异，利用这些因子可以对核事故发生时叶状作物可食用部位放射性元素131 I和放射性元素的活性浓度进行粗略估计。
{"title":"Mass Interception Fractions and Weathering Half-lives of Iodine-131 and Radiocesium in Leafy Vegetables Observed after the Fukushima Daiichi Nuclear Power Plant Accident","authors":"K. Tagami, S. Uchida","doi":"10.14407/jrpr.2021.00164","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00164","url":null,"abstract":"Background: This study was carried out to provide environmental transfer parameter values to estimate activity concentrations of these radionuclides in agricultural crops when direct contamination occurred. Materials and Methods: Mass interception fractions ( F B s) and weathering half-lives ( T w s) of 131 I and radiocesium were calculated using openly available monitoring data obtained after the Fukushima Daiichi Nuclear Power Plant accident. F B is the ratio between the initial radioactivity concentration of a radionuclide retained by the edible part of the plant (Bq ‧ kg -1 fresh weight [FW]) and the amount of deposited radionuclide in that area (Bq ‧ m -2 ). T w values can be calculated using activity concentrations of crops decreased with time after the initial contamination. Results and Discussion: Calculated F B and T w values for 131 I and radiocesium were mostly obtained for leafy vegetables. The analytical results showed that there was no difference of F B s between 131 I and radiocesium by t -test; geometric mean values for leafy vegetables cultivated under outdoor conditions were 0.058 and 0.12 m 2 ‧ kg -1 FW, respectively. Geometric mean T w value of 131 I in leafy vegetables grown under outdoor conditions was 8.6 days, and that of radiocesium was 6.6 days; there was no significant difference between T w values of these radionuclides by Wilcoxon rank sum test. Conclusion: There was no difference between 131 I and radiocesium for F B s and T w s. By using these factors, we would be able to carry out a rough estimation of the activity concentrations of 131 I and radiocesium in the edible part of leafy crops when a nuclear accident occurred.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"32 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84795409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-25DOI: 10.14407/jrpr.2021.00066
Tae-Eun Kwon, Seokwon Yoon, Wi-Ho Ha, Yoonsun Chung, Y. Jin
Background: The International Commission on Radiological Protection is preparing to pro-vide reference dose coefficients for environmental radioiodine intake based on newly developed age-specific biokinetic models. However, the biokinetics of iodine has been reported to be strongly dependent on the dietary intake of stable iodine; for example, the thyroidal uptake of iodine may be substantially lower in iodine-rich regions than in iodine-deficient regions. There-fore, this study attempted to establish a system of age-specific thyroid dose estimation for South Koreans, whose daily iodine intakes are significantly higher than that of the world population. Materials and Methods: Korean age-specific biokinetic parameters and thyroid masses were derived based on the previously developed Korean adult model and the Korean anatomical reference data for adults, respectively. This study complied with the principles used in the development of age-specific biokinetic models for world population and used the ratios of baseline values for each age group relative to the value for adults to derive age-specific values. Results and Discussion: Biokinetic model predictions based on the Korean age-specific parameters showed significant differences in iodine behaviors in the body compared to those predicted using the model for the world population. In particular, the Korean age-specific thyroid dose coefficients for 129 I and 131 I were considerably lower than those calculated for the world population (25%–76% of the values for the world population). Conclusion: These differences stress the need for Korean-specific internal dose assessments for infants and children, which can be achieved by using the data calculated in this study.
{"title":"Age-Specific Thyroid Internal Dose Estimation for Koreans","authors":"Tae-Eun Kwon, Seokwon Yoon, Wi-Ho Ha, Yoonsun Chung, Y. Jin","doi":"10.14407/jrpr.2021.00066","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00066","url":null,"abstract":"Background: The International Commission on Radiological Protection is preparing to pro-vide reference dose coefficients for environmental radioiodine intake based on newly developed age-specific biokinetic models. However, the biokinetics of iodine has been reported to be strongly dependent on the dietary intake of stable iodine; for example, the thyroidal uptake of iodine may be substantially lower in iodine-rich regions than in iodine-deficient regions. There-fore, this study attempted to establish a system of age-specific thyroid dose estimation for South Koreans, whose daily iodine intakes are significantly higher than that of the world population. Materials and Methods: Korean age-specific biokinetic parameters and thyroid masses were derived based on the previously developed Korean adult model and the Korean anatomical reference data for adults, respectively. This study complied with the principles used in the development of age-specific biokinetic models for world population and used the ratios of baseline values for each age group relative to the value for adults to derive age-specific values. Results and Discussion: Biokinetic model predictions based on the Korean age-specific parameters showed significant differences in iodine behaviors in the body compared to those predicted using the model for the world population. In particular, the Korean age-specific thyroid dose coefficients for 129 I and 131 I were considerably lower than those calculated for the world population (25%–76% of the values for the world population). Conclusion: These differences stress the need for Korean-specific internal dose assessments for infants and children, which can be achieved by using the data calculated in this study.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"94 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89672372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-27DOI: 10.14407/jrpr.2021.00206
Byoungil Jeon, Jongyul Kim, Yonggyun Yu, Myungkook Moon
Background: Identification of radioisotopes for plastic scintillation detectors is challenging because their spectra have poor energy resolutions and lack photo peaks. To overcome this weak-ness, many researchers have conducted radioisotope identification studies using machine learning algorithms; however, the effect of data normalization on radioisotope identification has not been addressed yet. Furthermore, studies on machine learning-based radioisotope identifiers for plastic scintillation detectors are limited. Materials and Methods: In this study, machine learning-based radioisotope identifiers were implemented, and their performances according to data normalization methods were compared. Eight classes of radioisotopes consisting of combinations of 22 Na, 60 Co, and 137 Cs, and the background, were defined. The training set was generated by the random sampling technique based on probabilistic density functions acquired by experiments and simulations, and test set was acquired by experiments. Support vector machine (SVM), artificial neural network (ANN), and convolutional neural network (CNN) were implemented as radioisotope identifiers with six data normalization methods, and trained using the generated training set. Results and Discussion: The implemented identifiers were evaluated by test sets acquired by experiments with and without gain shifts to confirm the robustness of the identifiers against the gain shift effect. Among the three machine learning-based radioisotope identifiers, prediction accuracy followed the order SVM > ANN > CNN, while the training time followed the order SVM > ANN > CNN. Conclusion: The prediction accuracy for the combined test sets was highest with the SVM. The CNN exhibited a minimum variation in prediction accuracy for each class, even though it had the lowest prediction accuracy for the combined test sets among three identifiers. The SVM exhibited the highest prediction accuracy for the combined test sets, and its training time was the shortest among three identifiers.
背景:塑料闪烁探测器的放射性同位素鉴定是具有挑战性的，因为它们的光谱具有较差的能量分辨率和缺乏光峰。为了克服这一弱点，许多研究人员使用机器学习算法进行了放射性同位素识别研究;然而，数据归一化对放射性同位素鉴定的影响尚未得到解决。此外，基于机器学习的放射性同位素标识符在塑料闪烁探测器上的研究也很有限。材料与方法:在本研究中，实现了基于机器学习的放射性同位素标识符，并根据数据归一化方法比较了它们的性能。确定了由22 Na、60 Co和137 Cs组成的8类放射性同位素和背景。基于实验和仿真得到的概率密度函数，采用随机抽样技术生成训练集，通过实验得到测试集。采用六种数据归一化方法将支持向量机(SVM)、人工神经网络(ANN)和卷积神经网络(CNN)实现为放射性同位素标识符，并使用生成的训练集进行训练。结果和讨论:实现的标识符通过有增益移位和没有增益移位的实验获得的测试集进行评估，以确认标识符对增益移位效应的鲁棒性。在三种基于机器学习的放射性同位素标识符中，预测精度遵循有序SVM > ANN > CNN，训练时间遵循有序SVM > ANN > CNN。结论:支持向量机对组合测试集的预测精度最高。CNN在每个类别的预测准确度上表现出最小的变化，尽管它在三个标识符中对组合测试集的预测准确度最低。支持向量机对组合测试集的预测准确率最高，训练时间最短。
{"title":"Comparison of Machine Learning-Based Radioisotope Identifiers for Plastic Scintillation Detector","authors":"Byoungil Jeon, Jongyul Kim, Yonggyun Yu, Myungkook Moon","doi":"10.14407/jrpr.2021.00206","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00206","url":null,"abstract":"Background: Identification of radioisotopes for plastic scintillation detectors is challenging because their spectra have poor energy resolutions and lack photo peaks. To overcome this weak-ness, many researchers have conducted radioisotope identification studies using machine learning algorithms; however, the effect of data normalization on radioisotope identification has not been addressed yet. Furthermore, studies on machine learning-based radioisotope identifiers for plastic scintillation detectors are limited. Materials and Methods: In this study, machine learning-based radioisotope identifiers were implemented, and their performances according to data normalization methods were compared. Eight classes of radioisotopes consisting of combinations of 22 Na, 60 Co, and 137 Cs, and the background, were defined. The training set was generated by the random sampling technique based on probabilistic density functions acquired by experiments and simulations, and test set was acquired by experiments. Support vector machine (SVM), artificial neural network (ANN), and convolutional neural network (CNN) were implemented as radioisotope identifiers with six data normalization methods, and trained using the generated training set. Results and Discussion: The implemented identifiers were evaluated by test sets acquired by experiments with and without gain shifts to confirm the robustness of the identifiers against the gain shift effect. Among the three machine learning-based radioisotope identifiers, prediction accuracy followed the order SVM > ANN > CNN, while the training time followed the order SVM > ANN > CNN. Conclusion: The prediction accuracy for the combined test sets was highest with the SVM. The CNN exhibited a minimum variation in prediction accuracy for each class, even though it had the lowest prediction accuracy for the combined test sets among three identifiers. The SVM exhibited the highest prediction accuracy for the combined test sets, and its training time was the shortest among three identifiers.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"48 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78281906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-05DOI: 10.14407/jrpr.2021.00136
Choonsik Lee
Background: Computed tomography (CT) is one of the crucial diagnostic tools in modern medicine. However, careful monitoring of radiation dose for CT patients is essential since the procedure involves ionizing radiation, a known carcinogen. Materials and Methods: The most desirable CT dose descriptor for risk analysis is the organ absorbed dose. A variety of CT organ dose calculators currently available were reviewed in this article. Results and Discussion: Key common elements included in CT dose calculators were discussed and compared, such as computational human phantoms, CT scanner models, organ dose database, effective dose calculation methods, tube current modulation modeling, and user interface platforms. Conclusion: It is envisioned that more research needs to be conducted to more accurately map CT coverage on computational human phantoms, to automatically segment organs and tissues for patient-specific dose calculations, and to accurately estimate radiation dose in the cone beam computed tomography process during image-guided radiation therapy.
{"title":"A Review of Organ Dose Calculation Tools for Patients Undergoing Computed Tomography Scans","authors":"Choonsik Lee","doi":"10.14407/jrpr.2021.00136","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00136","url":null,"abstract":"Background: Computed tomography (CT) is one of the crucial diagnostic tools in modern medicine. However, careful monitoring of radiation dose for CT patients is essential since the procedure involves ionizing radiation, a known carcinogen. Materials and Methods: The most desirable CT dose descriptor for risk analysis is the organ absorbed dose. A variety of CT organ dose calculators currently available were reviewed in this article. Results and Discussion: Key common elements included in CT dose calculators were discussed and compared, such as computational human phantoms, CT scanner models, organ dose database, effective dose calculation methods, tube current modulation modeling, and user interface platforms. Conclusion: It is envisioned that more research needs to be conducted to more accurately map CT coverage on computational human phantoms, to automatically segment organs and tissues for patient-specific dose calculations, and to accurately estimate radiation dose in the cone beam computed tomography process during image-guided radiation therapy.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"82 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73676764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-15DOI: 10.14407/jrpr.2021.00017
Boram Song, Changsoo Kim, Junwoo Kim
Background: Dual-energy X-ray images (DEI) can distinguish or improve materials of interest in a two-dimensional radiographic image, by combining two images obtained from separate low and high energies. The concepts of DEI performance describing the performance of doubleexposure DEI systems in the Fourier domain been previously introduced, however, the performance of double-exposure DEI itself in terms of various parameters, has not been reported.
{"title":"Study on Dual-Energy Signal and Noise of Double-Exposure X-Ray Imaging for High Conspicuity","authors":"Boram Song, Changsoo Kim, Junwoo Kim","doi":"10.14407/jrpr.2021.00017","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00017","url":null,"abstract":"Background: Dual-energy X-ray images (DEI) can distinguish or improve materials of interest in a two-dimensional radiographic image, by combining two images obtained from separate low and high energies. The concepts of DEI performance describing the performance of doubleexposure DEI systems in the Fourier domain been previously introduced, however, the performance of double-exposure DEI itself in terms of various parameters, has not been reported.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"103 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90520778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.14407/jrpr.2020.00255
K. Shimada, M. Kai
Background: The lifetime risk of lung cancer incidence due to radiation for nonsmokers is overestimated because of the use of the average cancer baseline risk among a mixed population, including smokers. In recent years, the generalized multiplicative (GM)-excess relative risk (ERR) model has been developed in the life span study of atomic bomb survivors to consider the joint effect of radiation and smoking. Based on this background, this paper discusses the issues of radiation risk assessment considering smoking in two parts.Materials and Methods: In Part 1, we proposed a simple method of estimating the baseline risk for nonsmokers using current smoking data. We performed sensitivity analysis on baseline risk estimation to discuss the birth cohort effects. In Part 2, we applied the GM-ERR model for Japanese smokers to calculate lifetime attributable risk (LAR). We also performed a sensitivity analysis using other ERR models (e.g., simple additive (SA)-ERR model).Results and Discussion: In Part 1, the lifetime baseline risk from mixed population including smokers to nonsmokers decreased by 54% (44%–60%) for males and 24% (18%–29%) for females. In Part 2, comparison of LAR between SA- and GM-ERR models showed that if the radiation dose was ≤200 mGy or less, the difference between these ERR models was within the standard deviation of LAR due to the uncertainty of smoking information.Conclusion: The use of mixed population for baseline risk assessment overestimates the risk for lung cancer due to low-dose radiation exposure in Japanese males.
{"title":"Lifetime Risk Assessment of Lung Cancer Incidence for Nonsmokers in Japan Considering the Joint Effect of Radiation and Smoking Based on the Life Span Study of Atomic Bomb Survivors","authors":"K. Shimada, M. Kai","doi":"10.14407/jrpr.2020.00255","DOIUrl":"https://doi.org/10.14407/jrpr.2020.00255","url":null,"abstract":"Background: The lifetime risk of lung cancer incidence due to radiation for nonsmokers is overestimated because of the use of the average cancer baseline risk among a mixed population, including smokers. In recent years, the generalized multiplicative (GM)-excess relative risk (ERR) model has been developed in the life span study of atomic bomb survivors to consider the joint effect of radiation and smoking. Based on this background, this paper discusses the issues of radiation risk assessment considering smoking in two parts.Materials and Methods: In Part 1, we proposed a simple method of estimating the baseline risk for nonsmokers using current smoking data. We performed sensitivity analysis on baseline risk estimation to discuss the birth cohort effects. In Part 2, we applied the GM-ERR model for Japanese smokers to calculate lifetime attributable risk (LAR). We also performed a sensitivity analysis using other ERR models (e.g., simple additive (SA)-ERR model).Results and Discussion: In Part 1, the lifetime baseline risk from mixed population including smokers to nonsmokers decreased by 54% (44%–60%) for males and 24% (18%–29%) for females. In Part 2, comparison of LAR between SA- and GM-ERR models showed that if the radiation dose was ≤200 mGy or less, the difference between these ERR models was within the standard deviation of LAR due to the uncertainty of smoking information.Conclusion: The use of mixed population for baseline risk assessment overestimates the risk for lung cancer due to low-dose radiation exposure in Japanese males.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"7 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84356193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.14407/jrpr.2020.00269
Alexandra Schelleman, Chris Boyd
Background: This paper aims to evaluate the clinical utility and radiation dosimetry, for the mobile X-ray imaging of patients with known or suspected infectious diseases, through the window of an isolation room. The suitability of this technique for imaging coronavirus disease 2019 (COVID-19) patients is of particular focus here, although it is expected to have equal relevance to many infectious respiratory disease outbreaks.Materials and Methods: Two exposure levels were examined, a “typical” mobile exposure of 100 kVp/1.6 mAs and a “high” exposure of 120 kVp/5 mAs. Exposures of an anthropomorphic phantom were made, with and without a glass window present in the beam. The resultant phantom images were provided to experienced radiographers for image quality evaluation, using a Likert scale to rate the anatomical structure visibility.Results and Discussion: The incident air kerma doubled using the high exposure technique, from 29.47 μGy to 67.82 μGy and scattered radiation inside and outside the room increased. Despite an increase in beam energy, high exposure technique images received higher image quality scores than images acquired using lower exposure settings.Conclusion: Increased scattered radiation was very low and can be further mitigated by ensuring surrounding staff are appropriately distanced from both the patient and X-ray tube. Although an increase in incident air kerma was observed, practical advantages in infection control and personal protective equipment conservation were identified. Sites are encouraged to consider the use of this technique where appropriate, following the completion of standard justification practices.
{"title":"X-Rays through the Looking Glass: Mobile Imaging Dosimetry and Image Quality of Suspected COVID-19 Patients","authors":"Alexandra Schelleman, Chris Boyd","doi":"10.14407/jrpr.2020.00269","DOIUrl":"https://doi.org/10.14407/jrpr.2020.00269","url":null,"abstract":"Background: This paper aims to evaluate the clinical utility and radiation dosimetry, for the mobile X-ray imaging of patients with known or suspected infectious diseases, through the window of an isolation room. The suitability of this technique for imaging coronavirus disease 2019 (COVID-19) patients is of particular focus here, although it is expected to have equal relevance to many infectious respiratory disease outbreaks.Materials and Methods: Two exposure levels were examined, a “typical” mobile exposure of 100 kVp/1.6 mAs and a “high” exposure of 120 kVp/5 mAs. Exposures of an anthropomorphic phantom were made, with and without a glass window present in the beam. The resultant phantom images were provided to experienced radiographers for image quality evaluation, using a Likert scale to rate the anatomical structure visibility.Results and Discussion: The incident air kerma doubled using the high exposure technique, from 29.47 μGy to 67.82 μGy and scattered radiation inside and outside the room increased. Despite an increase in beam energy, high exposure technique images received higher image quality scores than images acquired using lower exposure settings.Conclusion: Increased scattered radiation was very low and can be further mitigated by ensuring surrounding staff are appropriately distanced from both the patient and X-ray tube. Although an increase in incident air kerma was observed, practical advantages in infection control and personal protective equipment conservation were identified. Sites are encouraged to consider the use of this technique where appropriate, following the completion of standard justification practices.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"15 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90311343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.14407/jrpr.2021.00087
Sooyeon Lim, N. Syam, Seongjin Maeng, Sang Hoon Lee
Background: Phosphogypsum is material produced as a byproduct in fertilizer industry and is generally used for building materials. This material may contain enhanced radium-226 (226Ra) activity concentration compared to its natural concentration that may lead to indoor radon accumulation. Therefore, an accurate measurement method is proposed in this study to determine 226Ra activity concentration in phosphogypsum sample, considering the potential radon leakage from the sample container.Materials and Methods: The International Atomic Energy Agency (IAEA) phosphogypsum reference material was used as a sample in this study. High-purity germanium (HPGe) gamma spectrometry was used to measure the activity concentration of the 226Ra decay products, i.e., 214Bi and 214Pb. Marinelli beakers sealed with three different sealing methods were used as sample containers. Due to the potential leakage of radon from the Marinelli beaker (MB), correction to the activity concentration resulted in gamma spectrometry is needed. Therefore, the leaked fraction of radon escaped from the sample container was calculated and added to the gamma spectrometry measured values.Results and Discussion: Total activity concentration of 226Ra was determined by summing up the activity concentration from gamma spectrometry measurement and calculated concentration from radon leakage correction method. The results obtained from 214Bi peak were 723.4 ± 4.0 Bq· kg-1 in MB1 and 719.2 ± 3.5 Bq· kg-1 in MB2 that showed about 5% discrepancy compared to the certified activity. Besides, results obtained from 214Pb peak were 741.9 ± 3.6 Bq· kg-1 in MB1 and 740.1 ± 3.4 Bq· kg-1 in MB2 that showed about 2% difference compared to the certified activity measurement of 226Ra concentration activity.Conclusion: The results show that radon leakage correction was calculated with insignificant discrepancy to the certified values and provided improvement to the gamma spectrometry. Therefore, measuring 226Ra activity concentration in TENORM (technologically enhanced naturally occurring radioactive material) sample using radon leakage correction can be concluded as a convenient and accurate method that can be easily conducted with simple calculation.
{"title":"Determination of 226Ra in TENORM Sample Considering Radon Leakage Correction","authors":"Sooyeon Lim, N. Syam, Seongjin Maeng, Sang Hoon Lee","doi":"10.14407/jrpr.2021.00087","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00087","url":null,"abstract":"Background: Phosphogypsum is material produced as a byproduct in fertilizer industry and is generally used for building materials. This material may contain enhanced radium-226 (226Ra) activity concentration compared to its natural concentration that may lead to indoor radon accumulation. Therefore, an accurate measurement method is proposed in this study to determine 226Ra activity concentration in phosphogypsum sample, considering the potential radon leakage from the sample container.Materials and Methods: The International Atomic Energy Agency (IAEA) phosphogypsum reference material was used as a sample in this study. High-purity germanium (HPGe) gamma spectrometry was used to measure the activity concentration of the 226Ra decay products, i.e., 214Bi and 214Pb. Marinelli beakers sealed with three different sealing methods were used as sample containers. Due to the potential leakage of radon from the Marinelli beaker (MB), correction to the activity concentration resulted in gamma spectrometry is needed. Therefore, the leaked fraction of radon escaped from the sample container was calculated and added to the gamma spectrometry measured values.Results and Discussion: Total activity concentration of 226Ra was determined by summing up the activity concentration from gamma spectrometry measurement and calculated concentration from radon leakage correction method. The results obtained from 214Bi peak were 723.4 ± 4.0 Bq· kg-1 in MB1 and 719.2 ± 3.5 Bq· kg-1 in MB2 that showed about 5% discrepancy compared to the certified activity. Besides, results obtained from 214Pb peak were 741.9 ± 3.6 Bq· kg-1 in MB1 and 740.1 ± 3.4 Bq· kg-1 in MB2 that showed about 2% difference compared to the certified activity measurement of 226Ra concentration activity.Conclusion: The results show that radon leakage correction was calculated with insignificant discrepancy to the certified values and provided improvement to the gamma spectrometry. Therefore, measuring 226Ra activity concentration in TENORM (technologically enhanced naturally occurring radioactive material) sample using radon leakage correction can be concluded as a convenient and accurate method that can be easily conducted with simple calculation.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"70 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84096942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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