放射诊断医疗照射指导水平的确定方法

目的 确定适用于中国国情的放射诊断医疗照射指导水平。方法 对放射诊断检查年频率和受检者剂量进行调查和测量。结果 确定了用于表征参考剂量的剂量学量、检测方法,以及推荐了18种放射诊断检查的医疗照射指导水平。结论 医疗照射指导水平的设立,必将推进医疗照射辐射防护最优化的深入发展。     

莱芜市医疗照射水平调查

目的 探讨由医疗照射电离辐射引起受检者与患者健康的潜在影响和可采用的有效控制管理技术措施,以改善医疗照射电离辐射防护卫生质量。方法 通过对医疗照射水平的调查研究,合理配置与使用医疗照射卫生资源,采用降低受检者与患者一次医疗照射电离辐射照射剂量,提高医疗照射检查阳性率和医疗技术成果控制医疗照射所致公众电离辐射剂量负担。结果 莱芜市1996年,1998年医疗照射检查频率每1 000人口分别是200.70人次和223.23人次,男、女性别之比为1:1.21;1996年、1998年医疗照射检查阳性率分别是64.48%,69.24%,X射线诊断检查平均每人次受照有效剂量3.61 mSv;1996、1998年度X射线受检者所致电离辐射集体剂量分别是529.680人·Sv和646.810人·Sv;1998年每次X射线诊断受检者平均辐射危险度40.89×10^-6。结论 公众所受电离辐射最大人为因素主要源于医疗照射。对其加强监督管理和有效防护是改善医疗照射电离辐射防护卫生质量主要措施。     

医疗照射频度及X线诊断病人皮肤吸收剂量的调查

在人所受到的辐射剂量中医疗照射占有重要的地位，对医疗照射水平的研究是搞好整个辐射防护工作的关键。为此，我们对西安地区内医院的Ｘ线诊断、临床核医学检查及放射治疗的频度及５７４０人次Ｘ线诊断病人的皮肤吸收剂量进行了分层抽样调查。现将结果报告如下。１对象与...     

深圳市CT医疗照射所致居民剂量负担的研究

目的 了解深圳市CT医疗照射的现状,估计所致居民剂量负担。方法 采用普查方法,对2016年深圳市医疗机构中使用的CT进行调查。首先分头部、胸部、腹部和其他部位调查CT扫描人次和标准扫描参数,结合测量的加权CT剂量指数和文献结果,估算深圳市CT医疗照射所致居民的剂量负担。结果 2016年深圳市CT医疗照射频率为109.84人次/千人口,估算头部、胸部和腹部CT扫描的平均有效剂量分别为1.21 mSv、5.83 mSv和7.08 mSv。2016年深圳市CT医疗照射所致居民集体剂量为6090.28 Sv·人,人均年有效剂量为0.530 mSv。结论 CT医疗照射频率和单次扫描剂量是影响居民剂量负担大小的两个重要因素,减少一切不必要的照射和建立CT医疗照射指导水平是降低集体剂量负担的有效途径。     

商丘市医疗照射水平调查

在人类所受到的辐射剂量中医疗照射占有重要的地位,搞好医疗照射水平调查是搞好辐射防护工作的关键,根据全国"九五"期间医疗照射调查方案要求,我们于1999年对商丘市的医疗照射水平进行了调查,现将结果报告如下。     

医疗照射中应重视的问题

目的 合理应用医疗照射,做到趋利避害。方法 依据国际以及我国相关标准。结果 介绍了医疗照射的特点、现状及其所致剂量,提出了医疗照射中应再关注的问题。结论 要确保医用辐射安全,必须坚持医疗照射的正当化和防护最优化原则。     

现行放射诊疗卫生防护相关法规标准对医疗照射的控制

目的 分析现行法规标准对医疗照射的控制,探讨降低医疗照射的途径。方法 综合现行法规标准有关规定,对影响医疗照射的各种因素进行讨论。结果 现行法规标准在人员、设备和质控以及正当性判断与最优化、剂量指导水平等方面都提出了明确的要求。结论 通过提高准入条件,加强正当性判断、最优化和质量保证工作,推行医疗照射指导水平,合理降低医疗照射剂量,是目前放射诊疗卫生防护工作的重点。     

入托儿童X线透视时接受照射量的调查

胸部X线透视目前广泛应用于健康检查,据国内有关资料报道,健康人接受一次胸部X线透视,皮肤照射量为14—78毫伦,即可观察到淋巴细胞染色体畸变率和断片率高于正常的现象。为保障儿童健康、正确使用X线诊断提出依据,以及为估算群体辐射剂量提供参考,1982年我们对健康检查胸部X线透视的入托儿童,局部皮肤接受X线照射量进行了调查,并提出了降低受检者照射量的防护措施。内容和方法调查内容1982年8月对本区4个街道医院155名入托前儿童常规胸部X线透视检查时,监测了一次胸透局部皮肤接受的X线照射量。对     

放射诊断医疗照射指导剂量水平研究

"放射诊断医疗照射指导剂量水平"对放射诊疗单位降低受检者的剂量具有重要的指导意义.目前,一些发达国家制订了本国的指导剂量水平,对降低受检者剂量,促进医疗照射防护最优化具有重要意义.本文对我国部分放射诊断项目医疗照射指导剂量水平进行了探讨,对加快我国自己的放射诊断指导剂量水平制定的步伐有积极地促进作用.     

南平市典型成年受检者医疗照射水平调查研究

目的 了解南平市常见放射诊疗项目典型成年受检者的医疗照射水平,探索建立我市医疗照射指导水平,推进医疗照射防护最优化。方法 设计统一调查表对开展放射诊疗的部分单位开展放射诊疗的情况进行调查,同时利用RD-98剂量仪、标准水体模检测典型受检者入射皮肤剂量(entrance skin dose,ESD)。结果 胸片(前后位)的ESD为(0.528±0.871) mGy,腰椎(前后位)的ESD为(3.531±3.067) mGy,腰椎(正侧位)的ESD为(10.848±38.217) mGy,牙根尖周的ESD为(0.165±0.411) mGy。结论 我市常见诊疗项目的医疗照射水平与全国水平持平或更低,胸片(前后位)的指导水平高于基本标准中的指导水平。     

皮肤紫外线暴露剂量旋转人体模型方法测量

目的通过旋转人体模型测量不同解剖部位皮肤紫外线暴露剂量,确定额和颊的紫外线暴露与胸、肩及水平环境之间的转换比率关系,为准确定量个体皮肤尤其是面部紫外线暴露水平提供依据。方法在沈阳地区采用旋转人体模型进行额、颊、肩和胸部四季日间每间隔30 min累积紫外线暴露剂量的连续监测,同时监测水平环境紫外线作为对照。结果在沈阳地区,晴好天气下紫外线暴露剂量关系表现为,环境>肩部>额部>胸部>颊部,夏季>春秋季>冬季;额与胸、肩、水平环境紫外线的转换比率四季范围分别为1.17～1.32、0.65～1.10、0.51～1.09,颊与胸、肩、水平环境紫外线的转换比率四季范围分别为0.29～0.44、0.15～0.42、0.12～0.41。结论人群面部紫外线暴露定量可通过其与身体易于监测部位或环境紫外线进行转换得到,但转换比率适宜采用四季不同比值。     

摄影管压与受检者剂量关系研究

目的 研究摄影管压与受检者剂量的关系,探讨减少受检者剂量的方法。方法 利用仿真人模体,在保证影像负片质量的前提下,改变X射线管压和曝光时间,测量器官剂量和有效剂量。结果 对于胸片和腰椎片,在保证影像质量相同情况下,提高管压可使皮肤剂量减少50%,有效剂量减少约23%。结论 医用X射线诊断受检者的剂量仍有大幅度降低的余地。     

Population exposure to diagnostic use of ionizing radiation in The Netherlands

The use of ionizing radiation for diagnostic medical procedures and the exposure of the Dutch population to this radiation were assessed for 1998. The annual average effective dose from diagnostic medical exposures has increased by 26% to 0.59 mSv per capita since the last inventory of medical radiation exposure in the Netherlands a decade ago. The population-averaged effective dose comprises x-ray procedures in hospitals (87%), nuclear medicine examinations (11%), mammography screening (1.5%), and extramural dentistry (0.2%). The rise has resulted mainly from an increase in frequency and patient dose for CT examinations and from vascular radiology. The increase in the number of CT examinations leveled off in the mid-1990's. Medically exposed people were found to be significantly older than the general population. Based on age distribution alone, an "age reduction factor" for the risk coefficient of 0.64 was found to apply to the medically exposed group. More information on patient dose for the complete set of procedures should, according to this study, become available.     

上海市“九五”期间X射线诊断医疗照射剂量水平调查

[目的 ]　了解上海市“九五”期间X射线诊断医疗照射所致公众的剂量水平。　 [方法 ]　用TLD剂量计调查上海市 19种X射线诊断平均每次检查受检者体表剂量 ,估算平均每次检查所致受检者各器官吸收剂量及全身有效剂量当量 ,再结合上海市医疗照射调查频率数据 ,进一步估算X射线诊断检查所致公众集体剂量负担。　 [结果 ]　上海市19种X射线诊断检查所致公众年集体剂量当量 1996年为 5 2 0 .92人·Sv ,1998年为 5 46.93人·Sv ;19种X射线诊断检查所致全市年人均有效剂量当量 1996年为 0 .0 40mSv ,1998年为 0 .0 42mSv。　 [结论 ]　上海市X射线诊断医疗照射的剂量水平有增高的趋势 ,应重视医疗照射正确合理应用的问题     

Radiation exposure from work-related medical X-rays at the Portsmouth Naval Shipyard

BACKGROUND: Previous analyses suggest that worker radiation dose may be significantly increased by routine occupational X-ray examinations. Medical exposures are investigated for 570 civilian workers employed at the Portsmouth Naval Shipyard (PNS) at Kittery, Maine. The research objective was to determine the radiation exposure contribution of work-related chest X-rays (WRX) relative to conventional workplace radiation sources. METHODS: Methods were developed to estimate absorbed doses to the active (hematopoietic) bone marrow from X-ray examinations and workplace exposures using data extracted from worker dosimetry records (8,468) and health records (2,453). Dose distributions were examined for radiation and non-radiation workers. RESULTS: Photofluorographic chest examinations resulted in 82% of the dose from medical sources. Radiation workers received 26% of their collective dose from WRX and received 66% more WRX exposure than non-radiation workers. CONCLUSIONS: WRX can result in a significant fraction of the total dose, especially for radiation workers who were more likely to be subjected to routine medical monitoring. Omission of WRX from the total dose is a likely source of bias that can lead to dose category misclassification and may skew the epidemiologic dose-response assessment for cancers induced by the workplace.     

Effective patient education in medical imaging: public perceptions of radiation exposure risk

Patients perceptions of risk for harm influence their decisions concerning medical procedures and feelings of satisfaction with medical care choices. Radiologic technologists, dental hygienists, and other allied health professionals frequently are asked by patients to explain the radiation exposure dose and health risk associated with an imaging procedure. The purpose of this study was to evaluate the radiation risk perceptions within the community to develop an effective patient education strategy for health professionals based on the responses of 200 participants in a cross-sectional survey. Less than half of the adults responding to the survey agreed with experts regarding the risk of radiation exposure from various sources, and 75% to 90% of the responders thought that imaging providers should be highly educated and highly regulated. With efficacious patient education, appropriate risk comparisons can be made in simple terminology by addressing the public's knowledge, beliefs, and attitudes toward sources of radiation exposure.     

Dose estimate of exposure to radioisotopes in molecular and cellular biology.

A method for prospectively evaluating the annual equivalent doses and effective dose to biomedical researchers working with unsealed radioisotopes, and their classification, is presented here. Simplified formulae relate occupational data to a reasonable overestimate of the annual effective dose, and the equivalent doses to the hands and to the skin. The procedure, up to the classification of personnel and laboratories, can be made fully automatic, using a common spreadsheet on a personal computer. The method is based on occupational data, accounting for the amounts of each radioisotope used by a researcher, the time of exposure and the overall amounts employed in the laboratories where experiments are performed. The former data serve to forecast a contribution to the dose arising from a researcher's own work, the latter to a forecast of an 'environmental' contribution deriving simply from the presence in a laboratory where other people are working with radioisotopes. The estimates of the doses due to one's own radioisotope handling and to 'environment' were corrected for accidental exposure, considered as a linear function of the manipulated activity or of the time spent in the laboratories respectively, and summed up to give the effective dose. The effective dose associated with some common experiments in molecular and cellular biology is pre-evaluated by this method.     

Medical exposure of the population from diagnostic use of ionizing radiation in luxembourg between 1994 and 2002

A national evaluation on radiation doses from diagnostic procedures (x rays and nuclear medicine) was conducted in Luxembourg for the period 1994-2002 aiming at the estimation of the annual collective dose. The calculations were based on a survey of frequencies of more than 250 types of radiological examinations and included more than 425,000 patients. This evaluation ensured the practical implementation of Article 12 of the European Directive 97/43/EURATOM, which obliges the Member States to determinate the population dose from medical exposure. The results show an increase of the annual effective dose per capita from 1.59 mSv in 1994 to 1.98 mSv in 2002. The impact of computed tomography to dose received from medical use of radiation has dramatically increased in this time period. Luxembourg has one of the highest computed tomography examination rates compared to other health care level I countries. The following measures to minimize medical exposures were proposed in the study: medical physicists should have a more central role to play in patient dosimetry in interventional and diagnostic radiology, especially concerning computed tomography. Also, the implementation of an electronic "X-ray patient card" for all irradiated patients--except dental--and the use of the European referral criteria that give guidance and recommend investigations in various clinical settings can both help to decrease medical radiation exposures.     

Dose optimization for different medical imaging tasks from exposure index, exposure control factor, and MAS in digital radiography

ABSTRACT: In radiographic examination, not all medical imaging tasks require the same level of image quality or diagnostic information. Criteria should be established for different imaging tasks to avoid excessive doses where there is no clear net benefit in the diagnosis or the image quality. An exposure index provided by manufacturers would be a useful tool for this purpose. This study aims to establish an optimum exposure index to be used as a guideline for clinical imaging tasks to minimize radiation exposure for chest digital radiography. A three-level classification of image quality (high, medium, and low) for chest imaging tasks was carried out. An anthropomorphic phantom was employed to establish minimum exposure index and exposure (mAs) for clinical imaging task type I (corresponding to high image quality). The exposures of medium and low quality images derived from it. Thirty patients were exposed consecutively with these optimized exposure factors, and clinical tasks were considered, while another 30 patients were exposed with the exposure factors routinely used in practice. Image quality was assessed objectively by a consensus panel. The optimized exposure provided a significant reduction of the mean exposure index from 1,556 to 1,207 (p < 0.0001) and mean patient's entrance surface dose from 0.168 mGy to 0.092 mGy (p < 0.0001). The results show that a clinical-task-determined radiographic procedure is more conducive to radiation protection of patients. In this study, the posteroanterior chest imaging examination was chosen as an example. This procedure can also apply to other body parts and views.