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1.
Pediatr Radiol ; 54(1): 1-11, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38041712

RESUMO

In pediatric radiology, balancing diagnostic accuracy with reduced radiation exposure is paramount due to the heightened vulnerability of younger patients to radiation. Technological advancements in computed tomography (CT) reconstruction techniques, especially model-based iterative reconstruction and deep learning image reconstruction, have enabled significant reductions in radiation doses without compromising image quality. Deep learning image reconstruction, powered by deep learning algorithms, has demonstrated superiority over traditional techniques like filtered back projection, providing enhanced image quality, especially in pediatric head and cardiac CT scans. Photon-counting detector CT has emerged as another groundbreaking technology, allowing for high-resolution images while substantially reducing radiation doses, proving highly beneficial for pediatric patients requiring frequent imaging. Furthermore, cloud-based dose tracking software focuses on monitoring radiation exposure, ensuring adherence to safety standards. However, the deployment of these technologies presents challenges, including the need for large datasets, computational demands, and potential data privacy issues. This article provides a comprehensive exploration of these technological advancements, their clinical implications, and the ongoing efforts to enhance pediatric radiology's safety and effectiveness.


Assuntos
Radiologia , Tomografia Computadorizada por Raios X , Humanos , Criança , Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Software , Algoritmos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/métodos
2.
Sensors (Basel) ; 24(10)2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38793828

RESUMO

After the Fukushima nuclear power plant accident in 2011, many types of survey meters were used, including Geiger-Müller (GM) survey meters, which have long been used to measure ß-rays. Recently, however, a novel radiation survey meter that uses a plastic-scintillation sensor has been developed. Although manufacturers' catalog data are available for these survey meters, there have been no user reports on performance. In addition, the performance of commercial plastic-scintillation survey meters has not been evaluated. In this study, we experimentally compared the performance of a plastic-scintillation survey meter with that of a GM survey meter. The results show that the two instruments performed very similarly in most respects. The GM survey meter exhibited count losses when the radiation count rate was high, whereas the plastic-scintillation survey meter remained accurate under such circumstances, with almost no count loss at high radiation rates. For measurements at background rates (i.e., low counting rates), the counting rates of the plastic-scintillation and GM survey meters were similar. Therefore, an advantage of plastic-scintillation survey meters is that they are less affected by count loss than GM survey meters. We conclude that the plastic-scintillation survey meter is a useful ß-ray measuring/monitoring instrument.

3.
J Radiol Prot ; 44(3)2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38964291

RESUMO

Surgical procedures involving the use of x-rays in the operating room (OR) have increased in recent years, thereby increasing the exposure of OR staff to ionizing radiation. An individual dosimeter makes it possible to record the radiation exposure to which these personnel are exposed, but there is a lack of compliance in the wearing of these dosimeters for several practical reasons. This makes the dose results obtained unreliable. To try to improve the rate of dosimeter wearing in the OR, the Dosibadge project studied the association of the individual dosimeter with the hospital access badge, forming the Dosibadge. Through a study performed at the Tours University Hospital in eight different ORs for two consecutive periods of 3 months. The results show a significant increase in the systematic use of the dosimeter thanks to the Dosibadge, which improves the reliability of the doses obtained on the dosimeters and the monitoring of personnel. The increase is especially marked with clinicians. Following these results and the very positive feedback to this first single-centre study, we are then planning a second multicentre study to validate our proof of concept on different sites, with the three brands of individual dosimeters used in France i.e. dosimeters supplied by Dosilab; Landauer and IRSN.


Assuntos
Exposição Ocupacional , Salas Cirúrgicas , Doses de Radiação , Dosímetros de Radiação , Monitoramento de Radiação , Exposição Ocupacional/análise , Exposição Ocupacional/prevenção & controle , Humanos , Monitoramento de Radiação/métodos , Raios X , Proteção Radiológica , Exposição à Radiação/análise , Desenho de Equipamento
4.
Sensors (Basel) ; 22(15)2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35957277

RESUMO

Neutrons constitute a significant component of the secondary cosmic rays and are one of the most important contributors to natural cosmic ray radiation background dose. The study of the cosmic ray neutrons' contribution to the dose equivalent received by humans is an interesting and challenging task for the scientific community. In addition, international regulations demand assessing the biological risk due to radiation exposure for both workers and the general population. Because the dose rate due to cosmic radiation increases significantly with altitude, the objective of this work was to characterize the thermoluminescent dosimeter (TLDs) from the perspective of exposing them at high altitudes for longtime neutron dose monitoring. The pair of TLD-700 and TLD-600 is amply used to obtain the information on gamma and neutron dose in mixed neutron-gamma fields due to the present difference in 6Li isotope concentration. A thermoluminescence dosimeter system based on pair of TLD-600/700 was characterized to enable it for neutron dosimetry in the thermal energy range. The system was calibrated in terms of neutron ambient dose equivalent in an experimental setup using a 241Am-B radionuclide neutron source coated by a moderator material, polyethylene, creating a thermalized neutron field. Afterward, the pair of TLD-600/700 was exposed at the CERN-EU High-Energy Reference Field (CERF) facility in Geneva, which delivers a neutron field with a spectrum similar to that of secondary cosmic rays. The dosimetric system provided a dose value comparable with the calculated one demonstrating a good performance for neutron dosimetry.


Assuntos
Amerício , Dosímetros de Radiação , Altitude , Humanos , Nêutrons , Doses de Radiação , Dosimetria Termoluminescente
5.
Radiologe ; 61(1): 80-86, 2021 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-32816049

RESUMO

BACKGROUND: Transcatheter arterial chemoembolization (TACE) and biliary interventions are common procedures. OBJECTIVES: In this retrospective study, the radiation exposure of patients undergoing hepatic intervention will be analyzed and compared depending on the type and objective of the intervention. MATERIALS AND METHODS: This is an analysis of 7003 data sets of performed TACEs and biliary interventions from the DeGIR registry for the years 2016, 2017, and 2018. The dose area product (DAP), fluoroscopy time (FT), type of intervention, and anatomically defined target were recorded. RESULTS: Data with documented radiation doses were available for 4985 TACEs and for 2018 biliary interventions. For biliary interventions the median DAP was 2594 (interquartile range [IQR] = 1174-5858) cGycm2. For TACE, the median DAP was 11,632 [IQR = 5530-22,800] cGycm2 and significantly higher compared to biliary interventions (p < 0.0001). Biliary interventions with the highest DAP take place at the common hepatic duct; procedures with the longest FT were registered at the hepatic duct bifurcation. CONCLUSIONS: The individual radiation exposure during liver interventions is less dependent of the complexity of the procedure or the fluoroscopy time, but rather on the type of intervention and the anatomic target. The presented data can help to approximately estimate the radiation exposure in advance when planning an intervention.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Exposição à Radiação , Fluoroscopia , Humanos , Doses de Radiação , Sistema de Registros , Estudos Retrospectivos
6.
Sensors (Basel) ; 22(1)2021 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-35009632

RESUMO

For technical and radioprotection reasons, it has become essential to develop new dosimetric tools adapted to the specificities of computed tomography (CT) to ensure precise and efficient dosimetry since the current standards are not suitable for clinical use and for new CT technological evolution. Thanks to its many advantages, plastic scintillating fibers (PSF) is a good candidate for more accurate and personalized real-time dosimetry in computed tomography, and the company Fibermetrix has developed a new device named IVISCAN® based on this technology. In this study, we evaluated performances of IVISCAN® and associated uncertainties in terms of dose-rate dependence, angular dependence, stability with cumulative dose, repeatability, energy dependence, length dependence, and special uniformity in reference and clinical computed tomography beam qualities. For repeatability, the standard deviation is less than 0.039%, and the absolute uncertainty of repeatability lies between 0.017% and 0.025%. The deviation between IVISCAN® and the reference regarding energy dependence is less than 1.88% in clinical use. Dose rate dependence results show a maximum deviation under ±2%. Angular dependence standard deviation σ is 0.8%, and the absolute uncertainty was 1.6%. We observed 1% of variation every 50 Gy steps up to a cumulative dose of 500 Gy. Probe response was found to be independent of the PSF length with a maximum deviation ΔDsize < 2.7% between the IVISCAN® probe and the 1 cm PSF probe. The presented results demonstrated that IVISCAN® performances are in accordance with metrology references and the international standard IEC61674 relative to dosemeters used in X-ray diagnostic imaging and then make it an ideal candidate for real-time dosimetry in CT applications.


Assuntos
Radiometria , Tomografia Computadorizada por Raios X , Plásticos
7.
Sensors (Basel) ; 21(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34372394

RESUMO

Phosphorous-doped silica optical fibres with a core diameter of 4 µm were tested in X-ray and proton fields for application in cancer therapy dosimetry. Specifically, the radiation-induced attenuation was investigated in terms of linearity in deposited dose in 15 MV and 6 MV photons and 74 MeV protons, as well as Bragg-peak detection along the proton track. Fibres were found to demonstrate linear relative dose response in both radiation modalities, but possible saturation did occur at the high linear energy transfer of the Bragg peak. This demonstrates the possibility to use these fibres as a relative dosimeter for radiation therapy applications.


Assuntos
Terapia com Prótons , Humanos , Fósforo , Radiografia , Radiometria , Raios X
8.
Sensors (Basel) ; 21(22)2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34833705

RESUMO

As nuclear technology evolves, and continues to be used in various fields since its discovery less than a century ago, radiation safety has become a major concern to humans and the environment. Radiation monitoring plays a significant role in preventive radiological nuclear detection in nuclear facilities, hospitals, or in any activities associated with radioactive materials by acting as a tool to measure the risk of being exposed to radiation while reaping its benefit. Apart from in occupational settings, radiation monitoring is required in emergency responses to radiation incidents as well as outdoor radiation zones. Several radiation sensors have been developed, ranging from as simple as a Geiger-Muller counter to bulkier radiation systems such as the High Purity Germanium detector, with different functionality for use in different settings, but the inability to provide real-time data makes radiation monitoring activities less effective. The deployment of manned vehicles equipped with these radiation sensors reduces the scope of radiation monitoring operations significantly, but the safety of radiation monitoring operators is still compromised. Recently, the Internet of Things (IoT) technology has been introduced to the world and offered solutions to these limitations. This review elucidates a systematic understanding of the fundamental usage of the Internet of Drones for radiation monitoring purposes. The extension of essential functional blocks in IoT can be expanded across radiation monitoring industries, presenting several emerging research opportunities and challenges. This article offers a comprehensive review of the evolutionary application of IoT technology in nuclear and radiation monitoring. Finally, the security of the nuclear industry is discussed.


Assuntos
Internet das Coisas , Monitoramento de Radiação , Humanos , Tecnologia de Sensoriamento Remoto , Tecnologia , Tecnologia sem Fio
9.
J Radiol Prot ; 41(2)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33873176

RESUMO

Ionising radiation (IR) is increasingly being used in diagnostic and therapeutic procedures and offers increased benefits to patients but poses an increased occupational health risk to operators. The consistent use and monitoring of radiation health care workers' dosimeters is an important part of the process for ensuring adequate monitoring and control of IR in the workplace. There is however often inconsistent dosimeter utilisation among these workers. The aim of this study was to report on the dosimeter utilisation and dosimetry practices in South African interventionalists. We conducted a survey and did in-depth and group interviews to evaluate dosimetry practices and the factors influencing these practices. We used STATA 15 to do a descriptive analysis of the quantitative data. A thematic analysis of the qualitative data was done using a deductive and inductive approach. There were 108 respondents (35 radiologists, 41 adult cardiologists, 32 paediatric cardiologists). The majority overall (65.8%), and in each category were males. The median age was 44 (interquartile range (IQR) 31-66)) and the median years worked with fluoroscopy was 10 years (IQR 1-32). Overall interventionalists (55%) ranked their perceived occupation risk as 2/10. Thirteen per cent of all interventionalists reported never using a personal dosimeter (PD), 58% reported wearing it >70% of the time. Inconsistent and inappropriate use of PDs emerged strongly from the qualitative data. There was poor dosimeter utilisation in this study. Participants were not aware of the role of medical physics departments. Evaluation of dosimetry practices as a means of monitoring and improving radiation safety in the catheterisation laboratory must be improved to create an improved culture of radiation safety and protection.


Assuntos
Cardiologistas , Exposição Ocupacional , Adulto , Criança , Fluoroscopia , Humanos , Masculino , Exposição Ocupacional/análise , Doses de Radiação , Dosímetros de Radiação , Radiometria
10.
Eur Radiol ; 30(3): 1690-1700, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31748858

RESUMO

OBJECTIVES: To update the national diagnostic reference levels (DRLs) for adult CT in Switzerland using dose management software and to compare them to the previous Swiss DRLs from 2010. METHODS: CT dose data from 14 radiological institutes with a total of 50 CT scanners were collected with locally installed dose management software between 2014 and 2017. Data were assigned to 15 defined master protocols. Data cleaning steps were developed and adjusted individually for each participating institute and protocol. The DRLs for each master protocol were calculated as the 75th percentile of the distribution of the median volume computed tomography dose index (CTDIvol) and dose-length product (DLP) values per CT scanner. RESULTS: In total, 220,269 CT exams were available after data cleaning. Updated DRLs showed a clear trend towards lower doses compared with previous DRLs. The average relative change in the DRLs for CTDIvol was - 30% (0 to - 47%) and - 22% for DLP (+ 20 to - 40%). The largest relative decrease in the DRL for DLP was observed for the cervical spine protocol (- 40%), the two chest protocols (chest, - 37%; and exclusion of pulmonary embolism, - 33%), and the two neck protocols (neck, - 32%; and carotid angiography, - 28%). The DRLs for other protocols, for example the head and the abdomen-pelvis protocol, showed smaller relative changes (- 11% and - 17%). CONCLUSIONS: The updated national DRLs are substantially lower than the previous values from 2010, demonstrating technological progress and the efforts of the radiological community to lower CT radiation exposure. KEY POINTS: • Dose management software allows the establishment of DRLs based on big data. • Updated Swiss DRLs for adult CT are substantially lower compared with those from 2010. • Swiss DRLs are low compared with other national DRLs.


Assuntos
Algoritmos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Adulto , Humanos , Doses de Radiação , Exposição à Radiação , Valores de Referência , Software , Suíça
11.
Pacing Clin Electrophysiol ; 43(1): 87-92, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31710385

RESUMO

BACKGROUND: Little data are available about radiation exposure during cardiac electrical device implantation, and no dose reference levels have been published. This multicenter, prospective, observational study assesses patient and staff radiation exposure during cardiac device implantations, and aims at defining dose reference levels. METHODS: Patient demographic, procedural, and radiation data were obtained for 657 procedures from nine institutions. Physician and staff exposure were measured using real-time dosimeters worn beneath and above lead apron. Statistical analysis included fluoroscopy time (FT), dose-area product (DAP), and DAP adjusted for FT and body mass index. RESULTS: Pacemakers and cardioverter defibrillators were implanted in 481 and 176 patients, respectively. Of these, 152 were treated with cardiac resynchronization therapy (CRT). Median FTs were 837s (interquartile range [IQR]: 480-1323), 117s (IQR: 69-209), and 101s (IQR: 58-162), and median DAPs were 1410 (IQR: 807-2601), 150 (IQR: 72-338), and 129 (IQR: 72-332) cGy.cm² for biventricular, dual chamber, and ventricular device implantation, respectively. Dose reference levels correspond to the third quartile values. During CRT, higher exposure was observed with four X-ray systems than with the two newer and customizable ones (adjusted DAP of 0.90 [IQR: 0.26-1.01] and 0.29 [IQR: 0.23-0.39], respectively; P < .001). CONCLUSION: Based on real-life measurements, this multicenter registry provides dose reference levels and may help centers assess radiation exposure. Although biventricular device implantation was responsible for the highest radiation exposure, FT was meaningfully shortened compared to previously reported values. For a same FT, the use of new generators and custom settings has significantly reduced DAP.


Assuntos
Dispositivos de Terapia de Ressincronização Cardíaca , Exposição à Radiação , Proteção Radiológica/métodos , Idoso , Idoso de 80 Anos ou mais , Carga Corporal (Radioterapia) , Feminino , Fluoroscopia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Radiometria , Sistema de Registros
12.
Sensors (Basel) ; 20(24)2020 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-33419256

RESUMO

An appearance of radiometers and dosimeters on free sale made it possible to provide better radiation safety for citizens. The effects of radiation may not appear all at once. They can manifest themselves in decades to come in future generations, in the form of cancer, genetic mutations, etc. For this reason, we have developed in this paper a microcontroller-based radiation monitoring system. The system determines an accumulated radiation dose for a certain period, as well as gives alarm signals when the rate of the equivalent dose exceeds. The high reliability of this system is ensured by a rapid response to emergency situations: excess of the allowable power of the equivalent radiation dose and the accumulator charge control. Further, we have composed a microcontroller electronic circuit for the monitoring radiation system. Additionally, an operation algorithm, as well as software for the ATmega328P microcontroller of the Arduino Uno board, have been developed.

13.
Environ Monit Assess ; 192(6): 400, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32468213

RESUMO

Radiological data such as ambient dose equivalent rate obtained from radiation monitoring in Metro Manila are useful for the detection of any anomalous increase of radiation dose rate levels due to nuclear or radiological emergencies. In this study, ambient dose equivalent rates were measured in different locations in Metro Manila using a portable NaI(Tl) scintillation survey meter to determine the background radiation levels within the capital. Ambient dose equivalent rates measured range from 32.7 ± 2.2 to 59.3 ± 8.7 nanosieverts per hour (nSv/h) with computed mean and median values of 41.7 and 39.6 nSv/h, respectively. These values were lower than the Philippines' average dose rate which is 52 nanograys per hour (nGy/h). No significant trend was also observed in the monthly variation of ambient dose equivalent rate for most locations, with the dose rates being relatively consistent throughout a year. No significant trend was further observed in the monthly variation of ambient dose equivalent rate for the whole Metro Manila. Data obtained in this study were used to develop a dose rate distribution map of Metro Manila which could be used as a baseline reference of emergency responders for environmental radioactivity monitoring during nuclear or radiological emergencies that may affect Metro Manila.


Assuntos
Radiação de Fundo , Raios gama , Monitoramento de Radiação/instrumentação , Filipinas , Inquéritos e Questionários
14.
Can Assoc Radiol J ; 70(2): 119-124, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30772107

RESUMO

Several regulatory bodies have agreed that low-dose radiation used in medical imaging is a weak carcinogen that follows a linear, non-threshold model of cancer risk. While avoiding radiation is the best course of action to mitigate risk, computed tomography (CT) scans are often critical for diagnosis. In addition to the as low as reasonably achievable principle, a more concrete method of dose reduction for common CT imaging exams is the use of a diagnostic reference level (DRL). This paper examines Canada's national DRL values from the recent CT survey and compares it to published provincial DRLs as well as the DRLs in the United Kingdom and the United States of America for the 3 most common CT exams: head, chest, and abdomen/pelvis. Canada compares well on the international scale, but it should consider using more electronic dose monitoring solutions to create a culture of dose optimization.


Assuntos
Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Adulto , Canadá , Humanos , Guias de Prática Clínica como Assunto , Valores de Referência
15.
Eur Radiol ; 28(9): 3929-3935, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29594401

RESUMO

OBJECTIVES: To examine radiation dose levels of CT-guided interventional procedures of chest, abdomen, spine and extremities on different CT-scanner generations at a large multicentre institute. MATERIALS AND METHODS: 1,219 CT-guided interventional biopsies of different organ regions ((A) abdomen (n=516), (B) chest (n=528), (C) spine (n=134) and (D) extremities (n=41)) on different CT-scanners ((I) SOMATOM-Definition-AS+, (II) Volume-Zoom, (III) Emotion6) were included from 2013-2016. Important CT-parameters and standard dose-descriptors were retrospectively examined. Additionally, effective dose and organ doses were calculated using Monte-Carlo simulation, following ICRP103. RESULTS: Overall, radiation doses for CT interventions are highly dependent on CT-scanner generation: the newer the CT scanner, the lower the radiation dose imparted to patients. Mean effective doses for each of four procedures on available scanners are: (A) (I) 9.3mSv versus (II) 13.9mSv (B) (I) 7.3mSv versus (III) 11.4mSv (C) (I) 6.3mSv versus (II) 7.4mSv (D) (I) 4.3mSv versus (II) 10.8mSv. Standard dose descriptors [standard deviation (SD); CT dose indexvol (CTDIvol); dose-length product (DLPbody); size-specific dose estimate (SSDE)] were also compared. CONCLUSION: Effective dose, organ doses and SSDE for various CT-guided interventional biopsies on different CT-scanner generations following recommendations of the ICRP103 are provided. New CT-scanner generations involve markedly lower radiation doses versus older devices. KEY POINTS: • Effective dose, organ dose and SSDE are provided for CT-guided interventional examinations. • These data allow identifying organs at risk of higher radiation dose. • Detailed knowledge of radiation dose may contribute to a better individual risk-stratification. • New CT-scanner generations involve markedly lower radiation doses compared to older devices.


Assuntos
Biópsia Guiada por Imagem/métodos , Tomografia Computadorizada Multidetectores/métodos , Doses de Radiação , Exposição à Radiação , Abdome/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Extremidades/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Método de Monte Carlo , Imagens de Fantasmas , Estudos Retrospectivos , Coluna Vertebral/diagnóstico por imagem , Tórax/diagnóstico por imagem , Adulto Jovem
16.
Acta Radiol ; 59(3): 322-326, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28618854

RESUMO

Background The importance of monitoring of the radiation dose received by the human body during computed tomography (CT) examinations is not negligible. Several dose-monitoring software tools emerged in order to monitor and control dose distribution during CT examinations. Some software tools incorporate Monte Carlo Simulation (MCS) and allow calculation of effective dose and organ dose apart from standard dose descriptors. Purpose To verify the results of a dose-monitoring software tool based on MCS in assessment of effective and organ doses in thoracic CT protocols. Material and Methods Phantom measurements were performed with thermoluminescent dosimeters (TLD LiF:Mg,Ti) using two different thoracic CT protocols of the clinical routine: (I) standard CT thorax (CTT); and (II) CTT with high-pitch mode, P = 3.2. Radiation doses estimated with MCS and measured with TLDs were compared. Results Inter-modality comparison showed an excellent correlation between MCS-simulated and TLD-measured doses ((I) after localizer correction r = 0.81; (II) r = 0.87). The following effective and organ doses were determined: (I) (a) effective dose = MCS 1.2 mSv, TLD 1.3 mSv; (b) thyroid gland = MCS 2.8 mGy, TLD 2.5 mGy; (c) thymus = MCS 3.1 mGy, TLD 2.5 mGy; (d) bone marrow = MCS 0.8 mGy, TLD 0.9 mGy; (e) breast = MCS 2.5 mGy, TLD 2.2 mGy; (f) lung = MCS 2.8 mGy, TLD 2.7 mGy; (II) (a) effective dose = MCS 0.6 mSv, TLD 0.7 mSv; (b) thyroid gland = MCS 1.4 mGy, TLD 1.8 mGy; (c) thymus = MCS 1.4 mGy, TLD 1.8 mGy; (d) bone marrow = MCS 0.4 mGy, TLD 0.5 mGy; (e) breast = MCS 1.1 mGy, TLD 1.1 mGy; (f) lung = MCS 1.2 mGy, TLD 1.3 mGy. Conclusion Overall, in thoracic CT protocols, organ doses simulated by the dose-monitoring software tool were coherent to those measured by TLDs. Despite some challenges, the dose-monitoring software was capable of an accurate dose calculation.


Assuntos
Método de Monte Carlo , Doses de Radiação , Radiografia Torácica/métodos , Tomografia Computadorizada por Raios X/métodos , Humanos , Imagens de Fantasmas , Reprodutibilidade dos Testes , Software
17.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 36(11): 827-829, 2018 Nov 20.
Artigo em Zh | MEDLINE | ID: mdl-30646645

RESUMO

Objective: To understand the occupational external exposure dose among radiation workers in a first-class hospital at Grade 3 of Suzhou, and to provide reference for radiological protection. Methods: The individual dose of 1156 radiation workers in the hospital from 2010 to 2017 were detected, the annual collective effective dose and per capita annual effective dose were analyzed for different years, different occupations (diagnostic radiology, radiotherapy, nuclear medicine, interventional radiology) , gender, and age. Results: From 2010 to 2017, the total annual collective effective dose was 351.40 person·mSv, the per capita annual dose was 0.30 mSv/a, and radiation workers whose annual effective dose was less than 1 mSv accounted for 94.98%. There were 5 interventional radiology workers and 1 nuclear medicine worker with annual effective dose between 2 and 4 mSv. There was no worker with annual effective dose over 4 mSv. The per capita annual effective dose of nuclear medicine workers was the highest (0.40 mSv/a) . The per capita annual effective dose was not significantly different between radiation workers with different genders and ages (P>0.05) . Conclusion: Most of radiation workers have low individual dose level in the hospital. It is important to focus on nuclear medicine workers and interventional radiology workers.


Assuntos
Exposição Ocupacional/estatística & dados numéricos , Doses de Radiação , Monitoramento de Radiação , Serviço Hospitalar de Radiologia , China , Feminino , Humanos , Masculino , Proteção Radiológica
18.
Sensors (Basel) ; 17(9)2017 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-28841144

RESUMO

Due to some of their unique properties, optical fiber dosimeters are attractive and extensively researched devices in several radiation-related areas. This work evaluates the performance and potential of commercial perfluorinated polymer optical fibers (PF-POFs) for radiation monitoring applications. Gamma radiation-induced attenuation (RIA) of two commercial PF-POFs is evaluated in the VIS spectral region. Influence of a dose rate and temperature on RIA measurement is investigated, along with defect stability and measurement repeatability. Co-extruded PF-POFs are identified as more suitable for radiation monitoring applications due to lower dose-rate dependence. With co-extruded PF-POF, RIA measurement holds potential for highly-sensitive radiation monitoring with good reproducibility. The results show that operation in the blue part of the spectrum provides most favorable performance in terms of the largest nominal radiation sensitivity, lower temperature, and dose-rate dependence as well as higher defect stability. We demonstrate for the first time to our knowledge, that PF-POFs can be used for distributed detection of radiation with doses down to tens of Grays. The off-the-shelf, user-friendly PF-POF could be of interest as a cheap, disposable sensor for various applications, especially of a more qualitative nature.

19.
Sensors (Basel) ; 16(6)2016 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-27338392

RESUMO

In this study, a personal gamma (γ) spectrometer was developed for use in applications in various fields, such as homeland security and environmental radiation monitoring systems. The prototype consisted of a 3 × 3 × 20 mm³ Ce-doped Gd-Al-Ga-garnet (Ce:GAGG) crystal that was coupled to a Si photomultiplier (SiPM) to measure γ radiation. The γ spectrometer could be accessed remotely via a mobile device. At room temperature, the implemented Ce:GAGG-SiPM spectrometer achieved energy resolutions of 13.5%, 6.9%, 5.8%, and 2.3% for (133)Ba at 0.356 MeV, (22)Na at 0.511 MeV, (137)Cs at 0.662 MeV, and (60)Co at 1.33 MeV, respectively. It consumed only about 2.7 W of power, had a mass of just 340 g (including the battery), and measured only 5.0 × 7.0 cm².

20.
Appl Radiat Isot ; 206: 111210, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38382133

RESUMO

The aim of the presented paper is to examine the temperature drift and its unfolding for an environmental monitor equipped with a LaBr3(Ce) detector. It is known that temperature could influence energy, shape, and efficiency calibration. Consequently, when ambient temperature changes, the full energy absorption peak moves in the resulting spectrum. Research consists of experimental and analytical parts. During research in the climatic chamber, the dependence on temperature of energy, shape, and efficiency calibration was completed. The numerical method allows generating gamma spectra for theoretical so-called binary temperature variation.

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