辐射环境质量评价模式的建立

IAEA(国际原子能机构)对电离辐射照射伴有的危险的防护和可能产生这种照射的放射源安全提出了基本要求，强调“对放射源所致照射的性质、程度和可能的后果要进行评价”。很明显，要对释放到环境中的放射性所致辐照剂量进行评价，一定形式的环境评价模式是必不可少的。综合近年来辐射防护和放射生态学研究的有关献，对建立辐射剂量评价模式的基本要求进行了初步归纳。     

北京地区居民膳食摄入铀经胃肠道吸收入体液份额f1值的探讨

天然存在的辐射源除了以外照射的方式给人们以照射,也以内照射的方式加于人们。为了评价环境放射性所致人类的照射剂量,将放射性物质的摄入量转换成豫射剂量需要剂量转换系数。     

中国人受电离辐射照射剂量份额研究

系统总结了各种电离辐射源对正常生活条件的中国人所致照射剂量，为评价剂量－效应关系提供有意义的背景材料。方法基于大量调查研究和监测数据进行分析对比研究。结果中国人受各种电离辐射源的照射剂量，年有效剂量为２．５ｍＳｖ／ａ，来自天然辐射的剂量占总剂量的９２％。结论至今我国广大公众所受到的电离辐射照射仍以天然辐射为主。本文给出了各种电离辐射源所致剂量份额     

山东济宁60Co辐射事故受照人员物理剂量的模拟测量和估算

2004年10月21日山东省发生一起辐照加工用^60Co放射源事故。两名工人（A、B）在放射源处于工作状态时误入辐照室工作受到大剂量照射，造成重大放射事故。为了估算该事故受照人员的物理剂量，笔者先后对事故经过进行了调查，在现场对受照过程进行了模拟操作及物理剂量估算。     

放射治疗患者非治疗部位剂量调查

随着放射源在医疗卫生中应用的普及，医疗照射已成为人工辐射所致居民集体剂量当量的最大贡献者。对放射治疗中非有用线束的防护已成为辐射防护的重要问题之一。本文报告了放射治疗患者非治疗部位剂量调查情况。调查对象为我区某医院接受放射治疗的患者，共调查１４７例，...     

广东省妇女X线透环的性腺剂量和骨髓剂量的调查

本文应用国产氟化锂热释光剂量计调查了广东省。150例戴环妇女常规查环的局部X线照射量,根据MIXD均匀体模照射实验数据和有关资料计算了性腺剂量和骨髓剂量,得出一次透环的平均性腺剂量为13.6毫拉德,骨髓剂量为18.7毫拉德。估算了此种照射所致的骨髓集体剂量当量,并对其可能危害进行了简要讨论。     

天津市

为提供核技术应用的放射性环境背景资料和制定国家辐射防护标准及放射性环境质量评价的科学依据,我们于1983年5月～11月调查了天津地区环境天然辐射水平及所致居民照射剂量。     

一名工业γ射线探伤意外受照人员物理剂量估算

目的:对1名工业探伤过量受照人员物理剂量进行估算。方法:获取了主要照射参数,照射时间为8 min,照射方式为各向同性点源体外照射,放射源活度为2.183 TBq,采用中国参考人体素体模,利用基于Geant4二次开发的程序进行蒙特卡罗计算,得到各部位的吸收剂量。结果:给出了受照者手部剂量分布图,其中手掌大部分区域受照剂量...     

rhIL－6和rhG－CSF或rhGM－CSF联合应用对辐射引起灵长类动

为进一步缩短高剂量照射或药物所引起的骨髓增生不能所致白细胞和血小板减少的持续时间可能需要联合使用细胞因子,实验研究评价了IL-6(白细胞介素6)和G-CSF(粒细胞克隆刺激因子)或GM-CSF(粒巨细胞克隆刺激因子)联合应用时,同单独应用相比,对亚致死剂量照射后灵长类动物骨髓恢复的相对治疗功效。     

低剂量辐射流行病学研究——方法学问题的评价

辐射防护剂量限值所依据的辐射诱发癌症的估计主要来自对受0.5～10Gy剂量照射范围的人群调查.本文评价了低剂量辐射调查中存在的问题,重点分析已发表资料中方法学错误的可能来源及其对危险估算所致后果.     

Radiation hygiene in medical X-ray imaging: part 2: Assessment of radiation exposure and radiation protection measures

In order to secure and continually improve radiation protection standards in the field of medical X-ray imaging, the German X-Ray Ordinance requires that each individual examination be properly justified and that any procedure undertaken be optimized. Diagnostic reference levels have been introduced in Germany as a measure of optimization for common and/or high-dose X-ray procedures, and are regularly checked for compliance by the competent Medical Experts Office. A prerequisite for the implementation of these regulatory requirements is the determination of readily measurable dose quantities. They also form the basis for the estimation of organ doses and of the effective dose for exposure and risk assessment. The aim of this paper is to describe the essential dosimetric concepts and methods used for the assessment of radiographic, fluoroscopic, and CT procedures. In addition, practical measures for reducing the radiation exposure of patients and personnel will be discussed.     

Strahlenhygiene in der medizinischen Röntgenbildgebung

In order to secure and continually improve radiation protection standards in the field of medical X-ray imaging, the German X-Ray Ordinance requires that each individual examination be properly justified and that any procedure undertaken be optimized. Diagnostic reference levels have been introduced in Germany as a measure of optimization for common and/or high-dose X-ray procedures, and are regularly checked for compliance by the competent Medical Experts Office. A prerequisite for the implementation of these regulatory requirements is the determination of readily measurable dose quantities. They also form the basis for the estimation of organ doses and of the effective dose for exposure and risk assessment. The aim of this paper is to describe the essential dosimetric concepts and methods used for the assessment of radiographic, fluoroscopic, and CT procedures. In addition, practical measures for reducing the radiation exposure of patients and personnel will be discussed.     

The perspectives of users and developers in designing and developing O-arm imaging system

A questionnaire survey was performed to investigate the different knowledge of radiation exposure, awareness and expectation for O-arm imaging system between the users (orthopaedic surgeons) and the developers (engineers). A total of 93 orthopaedic surgeons and 19 engineers participated and answered the questionnaire consisting of 18 items designed for this study. The items were focused on knowlege, awareness, and expectation. Orthopaedic surgeons had higher scores for items of knowledge domains regarding radiation exposure than the engineers while the engineers were more sensitive to radiation hazards and adopted higher levels of radiation protection than orthopaedic surgeons in the awareness domain. Most engineers and orthopaedic surgeons answered that the requirements of diagnostic and intraoperative imaging systems differ. Image resolution, a low radiation exposure, and the time required for image acquisition was the top three requirements of O-arm selected by engineers. On the other hand, the top three requirements according to orthopaedic surgeons were; image resolution, expediency, and spatial occupancy. User requirements need to be reflected in developing O-arm along with basic requirements such as image resolution and low radiation exposure.     

Radiation hygiene in medical X-ray imaging. Part 3: radiation exposure of patients and risk assessment

The frequency of X-ray examinations in Germany and the resulting radiation exposure is amongst the highest in comparison with other European countries. To reduce medical radiation exposure and to safeguard radiation protection regulations, the X-ray ordinance stipulates a justification of each individual X-ray application. The justification principle means that the X-ray application should produce sufficient health benefit to offset the radiation risk. Such a benefit-risk assessment needs an adequate estimation of radiation risk. The aim of this paper is to explain the principles of benefit-risk assessment for different situations (e.g. healthcare and screening). The basics and concepts of radiation effects and radiation epidemiology as well as examples of risk estimation and benefit-risk assessments are given.     

Strahlenhygiene in der medizinischen Röntgenbildgebung

The frequency of X-ray examinations in Germany and the resulting radiation exposure is amongst the highest in comparison with other European countries. To reduce medical radiation exposure and to safeguard radiation protection regulations, the X-ray ordinance stipulates a justification of each individual X-ray application. The justification principle means that the X-ray application should produce sufficient health benefit to offset the radiation risk. Such a benefit-risk assessment needs an adequate estimation of radiation risk. The aim of this paper is to explain the principles of benefit-risk assessment for different situations (e.g. healthcare and screening). The basics and concepts of radiation effects and radiation epidemiology as well as examples of risk estimation and benefit-risk assessments are given.     

An assessment of Sri Lankan radiographer's knowledge and awareness of radiation protection and imaging parameters related to patient dose and image quality in computed tomography (CT)

IntroductionAs computed tomography (CT) examinations have considerably risen, safe operation is essential to reduce the patients’ dose. The main objective of this study was to evaluate the level of knowledge and awareness regarding the CT exposure parameters and radiation protection in CT imaging among Sri Lankan radiographers.MethodsAn online survey-based study was devised and distributed among the Sri Lankan CT radiographers working in 63 CT units. Questions were divided into three subsections that collected data on the participants’ demographic features, knowledge of the radiation protection, and imaging parameters.ResultsEighty-eight radiographers from 32 CT units (out of 63 CT units) distributed across 11 districts (out of 27 districts) participated in this survey.The percentages of correct responses for the questions related to radiation protection, imaging parameters, noise, Diagnostic Reference Level (DRL), and CT dosimetric parameters were 71%, 79%, 87%, 50%, and 66%, respectively. Although the years of experience did not influence any of above aspects, the level of education significantly impacted the knowledge about radiation protection, exposure parameters, and noise.ConclusionThe radiographer's knowledge of radiation protection and most imaging parameters associated with patient safety and image quality is satisfactory. However, findings also show that participants should fill the knowledge gap in radiation-related risks, CT exposure parameters, dosimetric parameters, and DRL.Implications for practiceThe study suggests the necessity of initiating continuous education programs for radiographers in line with national radiation protection legislation requirements that can be linked with code of practice.     

SPECT/螺旋CT融合技术的辐射风险与防护研究进展

大量临床研究已证实SPECT/螺旋CT一体机在疾病的诊断中具有独特的优势。然而反映功能影像的SPECT与反映解剖影像的螺旋CT同机进行采集必然会增加受检者所受辐射剂量,因此需要权衡融合显像诊断价值与辐射剂量的利弊。国际辐射防护委员会建议在对病人进行SPECT/螺旋CT检查时,应对病人所受的额外辐射剂量及可能增加的恶性肿瘤的发生概率予以充分考虑。SPECT/螺旋CT检查应遵循实践正当化与辐射防护最优化的原则,辐射水平不应超过国际规定的辐射剂量限值水平。     

What are the risks from medical X-rays and other low dose radiation?

The magnitude of the risks from low doses of radiation is one of the central questions in radiological protection. It is particularly relevant when discussing the justification and optimization of diagnostic medical exposures. Medical X-rays can undoubtedly confer substantial benefits in the healthcare of patients, but not without exposing them to effective doses ranging from a few microsieverts to a few tens of millisieverts. Do we have any evidence that these levels of exposure result in significant health risks to patients? The current consensus held by national and international radiological protection organizations is that, for these comparatively low doses, the most appropriate risk model is one in which the risk of radiation-induced cancer and hereditary disease is assumed to increase linearly with increasing radiation dose, with no threshold (the so-called linear no threshold (LNT) model). However, the LNT hypothesis has been challenged both by those who believe that low doses of radiation are more damaging than the hypothesis predicts and by those who believe that they are less harmful, and possibly even beneficial (often referred to as hormesis). This article reviews the evidence for and against both the LNT hypothesis and hormesis, and explains why the general scientific consensus is currently in favour of the LNT model as the most appropriate dose-response relationship for radiation protection purposes at low doses. Finally, the impact of the LNT model on the assessment of the risks from medical X-rays and how this affects the justification and optimization of such exposures is discussed.     

Standardizing measurement, sampling and reporting for public exposure assessments

UNSCEAR assesses worldwide public exposure from natural and man-made sources of ionizing radiation based on information submitted to UNSCEAR by United Nations Member States and from peer reviewed scientific literature. These assessments are used as a basis for radiation protection programs of international and national regulatory and research organizations. Although UNSCEAR describes its assessment methodologies, the data are based on various monitoring approaches. In order to reduce uncertainties and improve confidence in public exposure assessments, it would be necessary to harmonize the methodologies used for sampling, measuring and reporting of environmental results.     

立体放射防护在介入治疗中的应用

目的:评价立体放射防护方法在介入治疗中的防护效果及其应用价值。方法:174例患者,介入治疗中分别采用床下铅橡胶帘、床边悬挂可活动式铅玻璃防护屏、医用铅防护服、铅防护围脖、铅防护眼镜及增加距离等X射线辐射防护措施,利用RAD60S个人报警剂量仪测量防护材料防护前后的X射线辐射剂量,并进行统计学分析。结果:铅玻璃防护屏、铅防护服、距离的增加可明显减少X射线辐射剂量,有显著性防护意义;X射线辐射剂量与透视和数字减影血管造影时间呈正相关,随着透视和减影造影时间的增加,医务人员和患者所接受的X射线辐射剂量明显增加。结论:立体防护在介入治疗中可有效减少X射线辐射剂量,保护医务人员和患者的身体健康。