Radiation environment monitoring system based on the Internet of Things technology / 中国辐射卫生

This paper presents a nuclear radiation environment monitoring scheme based on the Internet of Things technology. The scheme primarily utilizes ZigBee wireless communication protocol, dedicated line network topology, and cloud-based processing techniques to achieve the entire process of acquisition, localization, transmission, tracking, monitoring, and management of X, γ, α, β, and neutron radiation data at nuclear radiation monitoring sites. Through initial application, the system demonstrates favorable characteristics such as good portability, strong scalability, secure information transmission, and deep data mining.

Development of a portable radiation detector for nuclide identification based on CdZnTe / 中国辐射卫生

Objective To develop a portable nuclear radiation detector with low-energy γ-nuclide recognition capability for rapid measurement of the dose levels in low-energy radiation fields and identification of nuclides. Methods A digital multi-channel circuit was developed for a detector based on the room temperature semiconductor cadmium zinc telluride, nuclide recognition was achieved using an intelligent nuclide recognition algorithm, and the energy response function G(E) was used to calculate the real-time ambient dose equivalent rate H*(10). Results The portable spectrometer had a minimum detectable energy of 20 keV, and the typical energy resolution for low-energy X-rays was > 4.10% at 59.5 keV and 20℃, enabling accurate identification of 241Am nuclide. Conclusion The device has a good measurement performance for low-energy γ/X rays, effectively addressing the limitations of existing devices for monitoring low-energy radiation fields, and provide reliable technical methods for monitoring and emergency response in spent fuel reprocessing plants or nuclear material production plants.

Factors influencing changes in total radioactivity in differentiated thyroid cancer patients after 131I treatment / 中华放射医学与防护杂志

Objective:To investigate the changes in total radioactivity in patient body with differentiated thyroid carcinoma (DTC) after 131I treatment and the factors influencing its metabolism. Methods:The clinical data from 218 patients after DTC treatment in the Department of Nuclear Medicine, the Second Affiliated Hospital of Air Force Medical University from September 2021 to April 2022 were retrospectively analyzed. Based on administrated 131I dose, 171 patients were divided into low-dose group (≤ 3.7 GBq) and 47 into high-dose group (>3.7 GBq) . A whole body dynamic radiation monitoring system was used to measure the in vivo residual activity of 131I 24, 48 and 72 h after 131I administration and to explore their influencing factors. Results:24, 48 and 72 h after adimination of 131I, the residual activity of 131I in the low-dose group patients was significantly lower than in the high-dose group patients ( t= -7.46, -3.31, -2.01, P<0.05) . The discharge compliance rate at 24 and 48 h in the low-dose group was significantly higher than that in the high-dose group (21.0% vs. 4.3%, 98.2% vs. 89.4%, χ2 = 7.23, 5.91, P<0.05) , and all patients could meet the discharge criteria at 72 h. Univariate analysis showed that the residual 131I activity at 24 and 48 h was dependent on age, body mass index (BMI) , basal metabolism rate (BMR) and thyroid stimulating hormone (TSH) . As have been shown by multiple linear regression analysis, in the low-dose group, the older age, the higher BMR and the higher TSH level at 24 h tended to the higher 131I residual activity in the body. At 48 h, the higher BMI and the higher TSH level lead to the higher 131I residual activity in patient body. Meanwhile, in the high-dose group, the higher age and BMR at 24 h, tended to the higher in vivo131I residual activity. The influencing factors were analyzed in terms that 131I residual activity reaching 400 MBq in patient body at 24 and 36 h. The result showed that at 24 h the lower TSH level leaded to the lower 131I residual activity in patient body. At 36 h, the younger age, the lower TSH level, and the smaller 131I treatment dose tended to the lower in vivo131I residual activity. Conclusions:Age, BMI, BMR and TSH levels are the influencing factors for the change in total activity in patient body after 131I treatment of DTC. Radiation dose assessment based on the above indicators can provide a reference for adjusting the length of hospitalization time.

Application of thermoluminescence dosimeter in environmental monitoring of nuclear power plant / 中国辐射卫生

Objective To investigate the effect of gaseous effluent from the six generator sets on the radiation level of the surrounding terrestrial environment in Daya Bay Nuclear Power Base after the operation of Ling’ao Nuclear Power plant. Methods The radiation level in the peripheral environment of the Base was monitored using the thermoluminescence dosimeter （TLD）. Twenty-five monitoring sites were set around the Base to investigate the variation of radiation level over a long period of time by collecting the TLDs every three months. Results From 2011 to 2020, the annual γ dose rate of the 25 sites ranged from 76.7 to 207.1 nGy/h, with an average value of (123.3 ± 5.7) nGy/h and a relative deviation of 2%-12%. The TLD monitoring and instantaneous measuring results of γ dose rate were consistent with the survey of the State Environmental Protection Administration in the 20th century and the baseline level prior to the operation of the nuclear power plant. Conclusion There are great differences in natural environmental radiation level across the TLD monitoring sites. The overall environmental γ radiation level within 50 km of the nuclear power base remains unchanged. The emission of gaseous effluent from the operation of the nuclear power plant does not have a cumulative impact on the radiation level of surrounding environment.

Analysis of basic situation of diagnostic radiology resources of the nationawide medical institutions / 中华放射医学与防护杂志

Objective:To analyze the distribution of radiodiagnosis resources in China and provide data support for further optimizing the allocation of radiodiagnosis resources and improving the weaknesses in radiation protection.Methods:The survey was carried out in accordance with the unified plan and using questionnaires of the national medical radiation protection monitoring program issued from 2017 to 2019. The survey included all medical institutions performing radiodiagnosis in China. The survey indicators included distribution of medical institutions performing radiodiagnosis, number of equipment, number of radiation workers and other information, the allocation of radiation protection equipment and the frequency of radiodiagnosis. The survey was performed using questionnaire survey and reported through the national medical radiation protection monitoring information system. In terms of the organization code, the name of the organizations excludes those repeatedly reported. The original data was exported in the form of excel table from the database for the purpose of statistical analysis.Results:By the end of 2019, except Xinjiang Production and Construction Corps, Hong Kong, Macao and Taiwan regions and military systems, there were 68 924 diagnostic radiology medical institutions in China, 147 913 diagnostic radiology equipment, accounting for 91.7% of the total pieces of nationwide diagnostic radioprotective equipment. There are 367 201 radiologists in China, accounting for 76.1% of 406 830 radiologists in all medical institutions, with high allocation rate of radiation protection equipment. However, the allocation rate in first-class hospitals was the lowest among all levels of hospitals. The piece of protection equipment was increased with the grade of hospital. From perspective of of economic development level, the highest was found in the eastern region, with the lowest in the central and northeast region, both of which are about 90%.Conclusions:The current status of radiodiagnosis and protection was ascertained basically through this three-year round of survey, with a large number of survey data accumulated. This survey provides data support for the development of relevant protection policies and standards at national and provincial levels. Survey data indicated that there are still nearly 1 000 direct fluorescent screen fluoroscopy machines in use in China. Relevant policies and standards should be established to gradually phase out the equipment with serious radiation hazards.

Tritium protection in the operation of nuclear energy / 中国辐射卫生

Tritium (3H) is an isotope of hydrogen. The main sources in the environment are natural tritium and artificial tritium.Artificially produced tritium appears as a by-product or a key fuel in the development of nuclear energy, and its release rate far exceeds that of natural tritium. The public's exposure to tritium in the environment is very low. Strategically speaking, the protection of tritium should focus on occupational exposure workers. This article briefly summarizes the nature, source, hazards, protection and pollution treatment of tritium, so that the public and radiation workers can understand relevant knowledge and do personal protection.

Application of portable γ-ray spectrometer in monitoring thyroid 131I in radiation workers / 中国辐射卫生

Objective To apply InSpector 1000 portable γ spectrometer and its corresponding supporting software to the monitoring of thyroid 131I activity of radiation workers, and to estimate the internal radiation dose of medical staff in nuclear medicine department. Methods The spectrometer was calibrated and taken to participate in the 2018 thyroid radioactive iodine intercomparison program initiated by Lawrence Livermore National Laboratory in the United States to ensure the accuracy of the measurement; the spectrometer was used to measure 131I activity ofthe radiation workers of the nuclear medicine departments of two grade-A tertiary hospitals in Beijing and Jinan to verify the feasibility of the method. Results The InSpector 1000 portable γ spectrometer was qualified for international intercomparison. Measurement results from the grade-A tertiary hospital in Beijing showed that the thyroid 131I activity of each of 10 radiation workers was below the detection limit (33.30 Bq). Measurement results from the grade-A tertiary hospital in Jinan showed that the thyroid 131I activities of the 4 radiation workers were 64.05 Bq, 160.77 Bq, 416.67 Bq, below the detection limit (35.18 Bq) respectively, and of 3 of the 4 subjects 131I was detected in the thyroid, and their corresponding thyroid accumulative organ doses were 0.70 μSv, 1.77 μSv, and 4.58 μSv, respectively. Conclusion InSpector 1000 portable γ spectrometer has a strong feasibility for thyroid 131I monitoring of radiation workers in nuclear medicine. The spectrometer has a good application prospect in the field of radiation monitoring, and can play an important role in the field of radiation protection and nuclear emergency detection.

CPHR: 35 años al Servicio de la Protección Radiológica, la Salud y el Medio Ambiente / CPHR: 35 years at the Service of Radiological Protection, Health and the Environment

Resumen El Centro de Protección e Higiene de las Radiaciones fue fundado en 1985 para sustentar la aplicación segura de las tecnologías nucleares en Cuba. En la actualidad la institución es considerada como una referencia nacional y regional en materia de seguridad radiológica, gracias a una sólida estrategia institucional que aporta de manera sostenida soluciones a problemas prioritarios del país. Este trabajo presenta una reseña de los principales resultados del centro hasta la fecha.

Abstract The Center for Radiation Protection and Hygiene was founded in 1985 to support the safe application of nuclear technologies in Cuba. Nowdays, the institution is considered as a national and regional reference for radiation protection , thanks to the comprehensive institutional strategy that support the solutions of the problems with priority in the country. The paper presents the overview about the main results of the center up today.

Analysis of individual dose monitoring results among radiation workers in a first-class hospital at Grade 3 from 2010 to 2017 / 中华劳动卫生职业病杂志

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.

¿Son reproducibles las mediciones dosimétricas a bajas dosis en cardiología intervencionista? / Are dosimetric measurements at low doses reproducible in interventional cardiology?

Abstract. There are several methods for measuring the absorbed radiation dose of occupationally exposed professionals, but it is unknown if these are reproducible at low doses. The aim of this study is to determine the level of reproducibility of thermoluminescent dosimeters (TLD) and optically stimulated luminescence dosimeters (OSL) in simulated conditions. A reproducibility study was performed using two types of dosimeters, which were placed in the location of medical interventionist work area inside the catheter laboratory. An anthropomorphic phantom was used as a patient and the same projections, collimation and radiographic techniques that were employed in the past 30 angiographies, an examination considered as low exposure in the context of interventional cardiology. Lin's concordance coefficient correlation was calculated, obtaining a value of -0.006 with a 95% CI of -0.069 to 0.056 for TLD dosimeters with OSL. The data obtained showed poor reproducibility at low doses of radiation.

Resumen. Existen varios métodos para medir la dosis de radiación absorbida por los profesionales ocupacionalmente expuestos, pero se desconoce si estos son reproducibles entre sí a bajas dosis. El objetivo del estudio fue determinar el grado de reproducibilidad entre los dosímetros termoluminiscentes (TLD) y los dosímetros luminiscentes ópticamente estimulados (OSL), en condiciones simuladas. Se realizó un estudio de reproducibilidad, empleando 2 tipos de dosímetros, los cuales se dispusieron en la ubicación de trabajo del médico intervencionista dentro del pabellón. Se empleó un fantoma antropomórfico como paciente y se replicaron las mismas proyecciones, colimación y técnicas radiológicas empleadas en las últimas 30 coronariografías, examen considerado de baja exposición en el contexto de cardiología intervencionista. Se aplicó el coeficiente de correlación de concordancia de Lin, obteniéndose un valor de -0,006 con un IC al 95% de -0,069 a 0,056 para los dosímetros TLD con OSL. Los datos obtenidos mostraron una escasa reproducibilidad a bajas dosis de radiación.

A dose monitoring system for dental radiography

PURPOSE: The current study investigates the feasibility of a platform for a nationwide dose monitoring system for dental radiography. The essential elements for an unerring system are also assessed. MATERIALS AND METHODS: An intraoral radiographic machine with 14 X-ray generators and five sensors, 45 panoramic radiographic machines, and 23 cone-beam computed tomography (CBCT) models used in Korean dental clinics were surveyed to investigate the type of dose report. A main server for storing the dose data from each radiographic machine was prepared. The dose report transfer pathways from the radiographic machine to the main sever were constructed. An effective dose calculation method was created based on the machine specifications and the exposure parameters of three intraoral radiographic machines, five panoramic radiographic machines, and four CBCTs. A viewing system was developed for both dentists and patients to view the calculated effective dose. Each procedure and the main server were integrated into one system. RESULTS: The dose data from each type of radiographic machine was successfully transferred to the main server and converted into an effective dose. The effective dose stored in the main server is automatically connected to a viewing program for dentist and patient access. CONCLUSION: A patient radiation dose monitoring system is feasible for dental clinics. Future research in cooperation with clinicians, industry, and radiologists is needed to ensure format convertibility for an efficient dose monitoring system to monitor unexpected radiation dose.

Does Ad Hoc Coronary Intervention Reduce Radiation Exposure? – Analysis of 568 Patients / Intervenção Coronariana Ad Hoc Reduz a Exposição Radiológica? - Análise em 568 Pacientes

Background:Advantages and disadvantages of ad hoc percutaneous coronary intervention have been described. However little is known about the radiation exposure of that procedure as compared with the staged intervention.Objective:To compare the radiation dose of the ad hoc percutaneous coronary intervention with that of the staged procedureMethods:The dose-area product and total Kerma were measured, and the doses of the diagnostic and therapeutic procedures were added. In addition, total fluoroscopic time and number of acquisitions were evaluated.Results:A total of 568 consecutive patients were treated with ad hoc percutaneous coronary intervention (n = 320) or staged percutaneous coronary intervention (n = 248). On admission, the ad hoc group had less hypertension (74.1% vs 81.9%; p = 0.035), dyslipidemia (57.8% vs. 67.7%; p = 0.02) and three-vessel disease (38.8% vs. 50.4%; p = 0.015). The ad hoc group was exposed to significantly lower radiation doses, even after baseline characteristic adjustment between both groups. The ad hoc group was exposed to a total dose-area product of 119.7 ± 70.7 Gycm2, while the staged group, to 139.2 ± 75.3 Gycm2 (p < 0.001).Conclusion:Ad hoc percutaneous coronary intervention reduced radiation exposure as compared with diagnostic and therapeutic procedures performed at two separate times.

Fundamento:Uma série de vantagens e desvantagens tem sido descrita para a intervenção coronária percutânea ad hoc, como a realizada ao mesmo tempo que o cateterismo diagnóstico, porém pouco se sabe sobre a exposição radiológica desse procedimento, comparado com a intervenção estadiada, ou seja, em dois momentos.Objetivo:Comparar a dose de radiação utilizada na angioplastia ad hoc com a angioplastia estadiada.Métodos:O produto de dose por área e o Kerma total foram mensurados, somando-se ambas as fases de diagnóstico e terapêutica. Além disso, foram computados o tempo total de fluoroscopia e o número de filmagens.Resultados:Um total de 568 pacientes consecutivos foram tratados com intervenção coronária percutânea ad hoc (n = 320) ou estadiada (n = 248). À admissão, o grupo do ad hoc apresentava menos hipertensão (74,1% vs. 81,9%; p = 0,035), dislipidemia (57,8% vs. 67,7%; p = 0,02) e doença triarterial (38,8% vs. 50,4%; p = 0,015). O grupo ad hoc foi exposto a doses significativamente menores de radiação, mesmo após ajuste para as diferenças basais entre os grupos. O grupo ad hoc foi exposto a uma dose de produto de dose por área total de 119,7 ± 70,7 Gycm2 enquanto que os pacientes estadiados foram expostos a uma dose de 139,2 ± 75,3 Gycm2 (p < 0,001).Conclusão:A intervenção coronária percutânea ad hoc reduziu a exposição radiológica, em comparação com procedimentos diagnósticos e terapêuticos realizados em tempos separados.

Radiation Safety and Education in the Applicants of the Final Test for the Expert of Pain Medicine

BACKGROUND: The C-arm fluoroscope is known as the most important equipment in pain interventions. This study was conducted to investigate the completion rate of education on radiation safety, the knowledge of radiation exposure, the use of radiation protection, and so on. METHODS: Unsigned questionnaires were collected from the 27 pain physicians who applied for the final test to become an expert in pain medicine in 2011. The survey was composed of 12 questions about the position of the hospital, the kind of hospital, the use of C-arm fluoroscopy, radiation safety education, knowledge of annual permissible radiation dose, use of radiation protection, and efforts to reduce radiation exposure. RESULTS: In this study, although most respondents (93%) had used C-arm fluoroscopy, only 33% of the physicians completed radiation safety education. Even though nine (33%) had received education on radiation safety, none of the physicians knew the annual permissible radiation dose. In comparing the radiation safety education group and the no-education group, the rate of wearing radiation-protective glasses or goggles and the use of radiation badges or dosimeters were significantly higher in the education group. However, in the use of other protective equipment, knowledge of radiation safety, and efforts to reduce radiation exposure, there were no statistical differences between the two groups. CONCLUSIONS: The respondents knew very little about radiation safety and had low interest in their radiation exposure. To make the use of fluoroscopy safer, additional education, as well as attention to and knowledge of practices of radiation safety are required for pain physicians.

Radiation exposure and its reduction in the fluoroscopic examination and fluoroscopy-guided interventional radiology

Radiation exposure during fluoroscopy has been of consistent interest because fluoroscopy is used not only for diagnostic purposes such as upper gastrointestinal series but for many minimally-invasive treatments in various clinical fields. In 2000, the International Commission on Radiological Protection published the important report about the avoidance of radiation injuries from medical interventional procedures, and this report defined harm during fluoroscopic-guided interventional procedure and how to reduce the radiation dose of patients and staff. Two aspects of fluoroscopy exposure differ from other types of medical radiation exposure, including computed tomography. One is that the entrance surface dose during an interventional procedure may be very high, so the deterministic effects of radiation such as skin or corneal injury should be emphasized more than stochastic effects such as cancer risk. The other is that the variation in radiation exposure is great for the same kind of procedure, so it is very difficult to generate a reference level for the radiation dose. Therefore, it is necessary to develop a guideline for the use of fluoroscopy through a nationwide survey about irradiation during fluoroscopic examinations and fluoroscopy-guided intervention procedures. In conclusion, radiation exposure by fluoroscopic guided intervention is not negligible, and the practitioner should always aim to reduce radiation exposure during interventional procedures.

Exposición radiológica de los trabajadores y el público en la primera fase del ensayo clínico del Nimotuzumab marcado con para el tratamiento de tumores cerebrales en Cuba / Occupational and public exposures in RIT of brain tumors in Cuba

RESUMEN La primera fase del ensayo clínico del anticuerpo monoclonal humanizado h-R3 (Nimotuzumab) marcado con , para la radioinmunoterapia de tumores cerebrales malignos fue ejecutada durante el período 2002-2005 en Cuba. El objetivo del trabajo fue analizar los datos de la vigilancia radiológica realizada durante el estudio, con respecto a las dosis estimadas inicialmente. Estas últimas se calcularon para cada nivel de actividad, operación y cantidad total de pacientes, considerando el decaimiento radiactivo del y que una misma persona realizaba todas las operaciones. Se demostró que el riesgo radiológico de la práctica es aceptable. Las hipótesis conservadoras empleadas para los cálculos y el cumplimiento de los procedimientos de seguridad establecidos, determinaron que la exposición medida fuera inferior a la estimada. La realización de este trabajo constituye una referencia para la introducción y desarrollo de la radioinmunoterapia en Cuba.

ABSTRACT The first phase of the clinical trial using the humanized monoclonal antibody h-R3 (Nimotuzumab) labelled with , for radioimmunotherapy of brain malignant was performed during the period 2002-2005 in Cuba. The aim of this work was to analyze data from the radiological surveillance of this research compared to initially estimated doses. These latter were calculated for each activity level, operation and total quantity of patients, considering the radioactive decay of and taking into account that only one person carries out all of the operations. It was demonstrated that the radiation risk of the practice is acceptable. The conservative hypotheses for dose assessment and the compliance with established safety procedures during this trial showed that the measured exposure was lower than that estimated. This paper is a reference useful to introduce and develop the RIT in Cuba.

Low-dose CT coronary angiography with prospective electrocardiogram-triggering using dual-source CT scanner / 中华放射学杂志

Objective To evaluate low-dose CT coronary angiography with prospective electrocardiogram (ECG)-triggering using dual-source CT scanner.Methods Sixty-eight patients who underwent coronary CT angiography using a dual-source CT scanner were divided into 2 groups: group A (38 cases) and group B (30 cases).Prospective ECG-triggering sequence scan mode was employed for group A.Inclusion criteria included: heart rate <70 bpm, sinus rhythm, and heart rate fluctuation less than 10 bpm.Data acquisition was set at 70% of the RR-interval.Retrospective ECG-gating helical scan was performed for group B.Inclusion criteria included heart rates < 70 bpm and sinus rhythm.The exclusion criteria included heart failure and serious arrhythmias.In both groups, patients with a BMI≥24 kg/m2 were examined with a tube voltage of 120 kV, whereas patients with a BMI <24 kg/m2 were examined with a tube voltage of 100 kV.All images were transferred to a workstation for further processing and analysis.The imaging quality was evaluated.The imaging quality of coronary artery segments were compared with rank sum test between the two groups, and the radiation dose were compared with t test.Results A total of 476 coronary artery segments were evaluated in group A and 372 segments were evaluated in group B.The mean score of imaging quality for coronary artery segments in group A was 3.48±0.59 and that in group B was 3.53±0.58.There was no statistical difference in imaging quality between the two groups (Z=-1.432, P=0.187).The effective dose was on average (2.51±0.54) mSv (range 1.3--3.3 mSv) in group A, whereas on average (14.55±3.54) rosy (range 7.1--20.2 mSv) in group B.There was a statistical difference between the two groups (t=18.484, P=0.000).Conclusions Low-dose prospective ECG-triggering sequence scan in dual-source CT coronary angiography is feasible in patients with low heart rate and regular cardiac rhythm.This scan mode can substantially reduce radiation doses while preserving good diagnostic image quality.

Absorbed and effective dose from periapical radiography by portable intraoral x-ray machine / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study was to measure the absorbed dose and to calculate the effective dose for periapical radiography done by portable intraoral x-ray machines. MATERIALS AND METHODS: 14 full mouth, upper posterior and lower posterior periapical radiographs were taken by wall-type 1 and portable type 3 intraoral x-ray machines. Thermoluminescent dosemeters were placed at 23 sites at the layers of the tissue-equivalent ART woman phantom for dosimetry. Average tissue absorbed dose and radiation weighted dose were calculated for each major anatomical site. Effective dose was calculated using 2005 ICRP tissue weighted factors. RESULTS: On 14 full mouth periapical radiographs, the effective dose for wall-type x-ray machine was 30 Sv; for portable x-ray machines were 30 Sv, 22 Sv, 36 Sv. On upper posterior radiograph, the effective dose for wall-type x-ray machine was 4 Sv; for portable x-ray machines doses were 4 Sv, 3 Sv, 5 Sv. On lower posterior radiograph, the effective dose for wall type x-ray machine was 5 Sv; for portable x-ray machines doses were 4 Sv, 4 Sv, 5 Sv. CONCLUSION: Effective doses for periapical radiographs performed by portable intraoral x-ray machines were similar to doses for periapical radiographs taken by wall type intraoral x-ray machines.

Influence of Effective Dose on Patients for Different Z Value During Computed Tomography / 医疗卫生装备

Objective To investigate the influence of organ dose and effective dose on patients for different Z value during head,chest and abdomen CT scan. Methods With equispaced displacement on axis Z,organ dose and effective dose was estimated by using SR250 software with commonly used CT exposure parameters. Results Effective dose changed gradually for different Z value,some organ dose was sensitive to the Z location. Conclusion It is necessary to avoid X-ray sensitive organ in CT examination to minimize radiation risk.

The pathological view of the biomedical consequence of Chernobyl accident / 解放军医学杂志

The present paper described a method of classification of the diseases of victims exposed to low dose or low dose-rate radiation in the Chernobyl accident according to the characteristic changes of pathological morphology.The authors pointed out that several critical issues should be specially paid attention to during autopsy and research.It was also suggested,based on the eight symptoms and signs,that the multi-organ diseases in the young rescuers participating in the rescue task after the accident accelerated the ageing,thus rendering significant contribution to the field of bio-medicine.Three types of tissues or cells were mainly affected by the low dose or low dose-rate radiation exposure,the mechanisms and consequences were also addressed.The pathological morphology changes of the thyroid small follicular carcinoma of the residents in Kiev region were focused.

Monitoring of Individual Exposed Dose of Radiological Workers in Qinghai Province in 2001-2005 / 环境与健康杂志

Objective To know the dynamic dose of individual external exposure for radiological workers in Qinghai province from 2001 to 2005. Methods Individual exposed dose for 2 733 radiological workers were measured with thermoluminescent method. Results Individual average effective dose was less than 0.53 mSv/a, 97.84% of radiological workers dose was less than 5 mSv/a. Conclusion The individual external exposure level for radiological workers is less than 5 mSv/a in Qinghai Province and it does not exceed the national standard limit.