Occupational and patients effective radiation doses in dental imaging

2021 ◽  
pp. 109899
Author(s):  
Nissren Tamam ◽  
Aljuhara Al-Mugrin ◽  
Soad Mansour ◽  
Abdelrahman Elnour ◽  
Mustafa Musa ◽  
...  
2010 ◽  
Vol 6 (1) ◽  
pp. 15
Author(s):  
James P Earls ◽  
Jonathon A Leipsic ◽  
◽  

Recent reports have raised general awareness that cardiac computed tomography (CT) has the potential for relatively high effective radiation doses. While the actual amount of risk this poses to the patient is controversial, the increasing concern has led to a great deal of research on new CT techniques capable of imaging the heart at substantially lower radiation doses than was available only a few years ago. Methods of dose reduction include optimised selection of user-defined parameters, such as tube current and voltage, as well as use of new technologies, such as prospective triggering and iterative reconstruction. These techniques have each been shown to lead to substantial reduction in radiation dose without loss of diagnostic accuracy. This article will review the most frequently used and widely available methods for radiation dose reduction in cardiac CT and give practical advice on their use and limitations.


2021 ◽  
Vol 66 (2) ◽  
pp. 59-66
Author(s):  
E. Matkevich

Purpose: To assess effective radiation doses for chest CT for the diagnosis of COVID-19 and calculate the radiation risk of the effects of this exposure. Material and methods: We analyzed the results of 1003 CT examinations of the chest performed in patients (6.2 %‒children 12–14 years, 15.3 %‒adolescents 15–19 years, 60.1 %‒adults 20–64 years, 18.4 %‒older persons 65 years and older) with suspected COVID-19 during one week in October 2020 in the city diagnostic center. In each group, the average effective dose (ED, mSv) was calculated. Results: The average ED values and confidence intervals (P=0.05) for patients with a single CT scan were: in children 2.59±0.19 mSv, in adolescents 3.23±0.17 mSv, in adults 3.43±0.08 mSv, in older persons 3.28±0.19 mSv. The maximum radiation risk indicators were observed in groups of children (24.1×10-5) and adolescents (23.3×10-5). For adult patients the means risk was 14.4×10-5. In groups of women radiation risk was 1.3–2.3 twice as high, as in male patients. The risk values in children, adolescents and adults are in the range 10×10-5 – 100×10-5 (low), for the older patients were 2.6×10-5 (very low). Conclusion: Because of the study established effective radiation doses for chest CT of patients with the diagnosis of COVID-19 and the radiation risk for 1-3 times chest CT by age and sex of patients was calculated. It was found that the radiation risk for single, double and triple chest CT for patients under 65 is low, 65 and older is very low. Taking into account the radiation risk during CT is necessary to reduce the long-term consequences of radiation exposure on the population.


Author(s):  
N. Gunko ◽  
◽  
O. Ivanova ◽  
K. Loganovsky ◽  
N. Korotkova ◽  
...  

Background. Radiation accidents at the Chornobyl Nuclear Power Plant (USSR, 1986) and Fukushima-1 (Japan, 2011) have shown that global environmental contamination is an intervention in normal human life making negative effect on population health. These accidents highlighted a number of statutory and regulatory both with medical and social problems for individuals, who returned voluntarily for permanent residence in the Chornobyl Exclusion Zone i.e. a radiation-hazardous area (they are named the «self-settlers»). Objective: generalization of experience in the settlement of normative-legal, ecological-dosimetric and medicosocial life issues of population living in the Chornobyl NPP (ChNPP) Exclusion Zone («self-settlers»). Object and methods. The chosen problem is complex, necessitating the generalization of radiation-hygienic, medical-biological, socio-economic, demographic and sociological research results obtained by the national and foreign authors. A set of theoretical research and analysis of empirical data methods on the principles of interdisciplinary interaction was used; the systematic, legal, economic, medical-biological, demographic and retrospective-dosimetric approaches of research were applied. Results. It was shown that a part of population refused to evacuate or had returned for permanent residence to the radiation-hazardous lands after the ChNPP accident. In 1986–2009 the number of «self-settlers» ranged from 150 to 2,000 in different years. In 2021 – the 101 people. Those were mainly people of working age, mostly females, single people or widows/widowers. Рrevious medical and dosimetric studies have shown that long-term residence in the Exclusion Zone affects physical and mental health of «self-settlers» and causes atypical aging, including involvement of the central nervous system. According to calculations, the average effective total radiation dose accumulated by «self-settlers» for the first 3 years was 30 % of dose for the entire post-accident period, and the dose accumulated over 20 years was 54 % of the dose accumulated over 35 years. But the effective radiation doses accumulated in different periods after the accident differ significantly in residents of different Exclusion Zone settlements. This information needs further study in terms of the «radiation dose - health status» dependence. Conclusions. The effective radiation doses accumulated in different periods after the accident differ significantly in the residents of different Exclusion Zone settlements. Тhe average effective total radiation dose accumulated by «self-settlers» for the first 3 years was 30 % of the dose for the entire post-accident period, and the dose accumulated over 20 years was 54 % of the dose accumulated over 35 years. The Scientific Council meeting of NAMS approved the NRCRM Annual Report. Key words: Chornobyl Nuclear Power Plant, Exclusion Zone, «self-settlers», radiation doses, health.


2016 ◽  
Vol 25 (4) ◽  
pp. 230-234
Author(s):  
Wai-Yung Yu ◽  
Thye Sin Ho ◽  
Henry Ko ◽  
Wai-Yee Chan ◽  
Serene Ong ◽  
...  

Introduction: The use of computed tomography (CT) imaging as a diagnostic modality is increasing rapidly and CT is the dominant contributor to diagnostic medical radiation exposure. The aim of this project was to reduce the effective radiation dose to patients undergoing cranial CT examination, while maintaining diagnostic image quality. Methods: Data from a total of 1003, 132 and 27 patients were examined for three protocols: CT head, CT angiography (CTA), and CT perfusion (CTP), respectively. Following installation of adaptive iterative dose reduction (AIDR) 3D software, tube current was lowered in consecutive cycles, in a stepwise manner and effective radiation doses measured at each step. Results: Baseline effective radiation doses for CT head, CTA and CTP were 1.80, 3.60 and 3.96 mSv, at currents of 300, 280 and 130–150 mA, respectively. Using AIDR 3D and final reduced currents of 160, 190 and 70–100 mA for CT head, CTA and CTP gave effective doses of 1.29, 3.18 and 2.76 mSv, respectively. Conclusion: We demonstrated that satisfactory reductions in the effective radiation dose for CT head (28.3%), CTA (11.6%) and CTP (30.1%) can be achieved without sacrificing diagnostic image quality. We have also shown that iterative reconstruction techniques such as AIDR 3D can be effectively used to help reduce effective radiation dose. The dose reductions were performed within a short period and can be easily achievable, even in busy departments.


Author(s):  
Yong Li ◽  
Bingsheng Huang ◽  
Jun Cao ◽  
Tianqi Fang ◽  
Guoqing Liu ◽  
...  

Abstract The radiation doses absorbed by major organs of males and females were studied from three types of dental X-ray devices. The absorbed doses from cone-beam computed tomography (CBCT), panoramic and intraoral X-ray machines were in the range of 0.23–1314.85 μGy, and were observed to be high in organs and tissues located in or adjacent to the irradiated area, there were discrepancies in organ doses between male and female. Thyroid, salivary gland, eye lens and brain were the organs that received higher absorbed doses. The organ absorbed doses were considerably lower than the diagnostic reference level for dental radiography in China. The calculated effective radiation doses for males and females were 56.63, 8.15, 2.56 μSv and 55.18, 8.99, 2.39 μSv, respectively, when using CBCT, the panoramic X-ray machine and intraoral X-ray machine. The effective radiation dose caused by CBCT was much higher than those of panoramic and intraoral X-ray machines.


2021 ◽  
Vol 8 (2) ◽  
pp. 27-35
Author(s):  
Van Dung Nguyen ◽  
Dinh Thuan Dao ◽  
Hao Quang Nguyen

According to the United Nations Scientific Council on the Effects of Atomic Radiation(UNSCEAR), the global average dose level for the community is 2.4mSv/year. People living in the areas with high levels of radiation will cause adverse effects on their health. There are two main components that cause the dose of radiation, mainly due to the inhalation of radon and the extra dose of gamma radiation. The paper presents the results of assessment of natural effective radiation doses on the basis of the projected outpatient dosimetry in 70 households living in Mau and Mo village of Nam Xe, Phong Tho distrist, Lai Chau province.


2021 ◽  
pp. 20210388
Author(s):  
Makoto Hosono ◽  
Mamoru Takenaka ◽  
Hajime Monzen ◽  
Mikoto Tamura ◽  
Masatoshi Kudo ◽  
...  

Positron emission tomography (PET)/computed tomography (CT) is an essential imaging modality for the management of various diseases. Increasing numbers of PET/CT examinations are carried out across the world and deliver benefits to patients; however, there are concerns about the cumulative radiation doses from these examinations in patients. Compared to the radiation exposure delivered by CT, there have been few reports on the frequency of patients with a cumulative effective radiation dose of ≥100 mSv from repeated PET/CT examinations. The emerging dose tracking system facilitates surveys on patient cumulative doses by PET/CT because it can easily wrap up exposure doses of PET radiopharmaceuticals and CT. Regardless of the use of a dose tracking system, implementation of justification for PET/CT examinations and utilisation of dose reduction measures are key issues in coping with the cumulative dose in patients. Despite all the advantages of PET/MRI such as eliminating radiation exposure from CT and providing good tissue contrast in MRI, it is expensive and cannot be introduced at every facility; thus, it is still necessary to utilise PET/CT with radiation reduction measures in most clinical situations.


Author(s):  
V. Vasylenko ◽  
◽  
G. Zadorozhna ◽  
M. Kuriata ◽  
L. Lytvynetz ◽  
...  

Objective.to identificate the main factors and assess their impact on the formation of radiation doses to the population of radioactively contaminated areas of Kyiv region at the current stage of the accident based on complex radiation and hygienic monitoring in the reference settlements in 2019. Materials and methods. Comprehensive radiological and hygienic monitoring was carried out in eight settlements of Kyiv region – villages of Ragivka, Lygovyky, Mar’yanivka, Zelena Poliana of Polis’kyi district and villages of Hornostaipil, Dytiatky , Pisky, Karpylivka of Ivankiv district. The content of incorporated 137Сs was determined with direct measurement on whole body counters (WBC) samples of basic foodstuffs were collected to determine the content of radionuclides 90Sr and 137Сs, residents were interviewed about the levels of consumption of these products, and work was performed to estimate external radiation doses. Mathematical, dosimetric, radiochemical methods are used in the work. Results. There was a further decrease in annual doses of internal radiation in the surveyed settlements in 1.3 times, both in Polis’kyi district (0.041 mSv · year-1 in 2016, 0.030 mSv · year-1 in 2019) and in Ivankiv district (0.023 mSv · year-1 in 2016, 0.018 mSv · year-1 in 2019). It is possible to state a slowdown in the reduction of radiation doses compared to previous years: from 2010 to 2013, the annual doses of internal radiation in the surveyed settlements decreased by 1.8–2.4 times, from 2013 to 2016 – by 2.3–3.6 times. The content of 137Сs and 90Sr in milk and potatoes in the inspected settlements is lower than the permissible level of the Hygienic Standard HS 6.6.1.1-130-2006 and the use of these foods can not significantly affect the formation of the internal radiation dose. The content of 90Sr in milk samples in the settlements of Ivankiv district is in the range of 2.1–9.9 Bq · kg-1 (in 2016: 1.3–7.4 Bq · kg-1), which does not exceed the permissible level of 20 Bq · kg-1, but due to the dynamics needs further monitoring. The content of 137Сs in samples of dried mushrooms collected from residents of Kyiv region in 2019, as in previous years, is significantly (up to 100 times) higher than permissible level, and has a high uncertainty – from 1.4 kBq · kg-1 to 223.7 kBq · kg-1. Conclusions. It is established that the annual effective radiation doses of the population in the surveyed settlements in the current year are formed due to internal radiation doses that do not exceed 0.46 mSv · year-1 in Ivankiv district and 0.51 mSv · year-1 in Polis’kyi district, which below the RCT criterion 1 mSv · year-1. The main factor that forms the dose of internal radiation of the residents of the surveyed state of emergency of Kyiv region is the intake of 137Сs in the body with forest products, primarily mushrooms. Key words: internal dose, external irradiation; WBC-monitoring, 137Сs, 90Sr.


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