Basic Principles Of Radiation Protection Research Articles

Techniques and parameters for estimating radiation exposure and dose in cardiac computed tomography

With increasing clinical use of cardiac CT imaging it is important that all health care providers referring for or administering such examinations are familiar with the concepts and values of radiation dosimetry in CT as well as with the basic principles of radiation protection. There are important technical differences pertinent to radiation dose between the CT scanner types that are currently being used for imaging of the heart and coronary arteries. As a result of these differences, the radiation dose typically is higher when a cardiac examination is performed with multidetector-row CT (MDCT) than when it is performed with electron beam CT. Several techniques have been described to reduce radiation dose of MDCT imaging by varying the X-ray tube current during a CT examination. The volume computed tomographic dose index (CTDIvol), the dose length product (DLP), and the effective dose (E) are the most useful parameters to describe and compare radiation doses received from cardiac CT examinations. When comparing radiation doses between scanning protocols and scanner types, the degree of image noise must be considered. Diagnostic, rather than aesthetic, quality of images should be the most important factor guiding the development of scanning protocols for cardiac CT imaging. Cardiac CT examinations should be ordered only by qualified health care providers, and the ordering clinicians should be aware of their responsibility of weighing risks of the radiation exposure against the expected benefits.

Radiation protection principles of NCRP.

The current recommendations of the National Council on Radiation Protection and Measurements (NCRP) relative to ionizing radiation are based on radiation protection principles that developed historically as information about radiation effects on human populations became available. Because the NCRP Charter states that the NCRP will cooperate with the International Commission on Radiological Protection (ICRP), the basic principles and recommendations for radiation protection of the NCRP are closely coupled with those of the ICRP. Thus, the fundamental principles of justification, optimization, and dose limitation as initially stated in ICRP Publication 26 have been adopted and applied by the NCRP in its recommendations. ICRP and NCRP recommendations on dose limitation for the general public and for occupationally exposed individuals are based on the same analyses of radiation risk, and, while similar, there are differences reflecting the aspects of radiation application and exposure circumstances unique to the United States. The NCRP has recently extended its guidance to address exposure to individuals engaged in space activities. Several reports have been issued or are in preparation to provide recommendations on dose limitation and the development of radiation safety programs to apply the radiation protection principles in space activities. The biological basis for these recommendations is provided in these and accompanying NCRP reports. Recommendations for the application of basic radiation protection principles have been made in many reports over the years. Those that are most current appear in approximately 50 reports published in the last 15 y. These address radiation safety practices in industrial and medical institutions, control of radionuclides in the environment, protection of the public, and assessment of radiation risk. Some of the aspects of these recommendations will be discussed. Current recommendations related to radiation safety practice are based on the principles and dose limits specified in Report No. 116. The limits are based on estimates of the risk of fatal cancer and an assessment of the risk that should be tolerated by workers who are occupationally exposed and by the general public. These levels of risk are related to other risks that individuals accept in their lives. Looking to the future, one might consider other directions that the NCRP could take in developing radiation safety recommendations that are still based upon the stated principles, such as relating dose to loss of life expectancy instead of fatal cancer risk. It may also be that the principles of justification, optimization, and dose limitation should be reconsidered. For example, the NCRP may make recommendations about the relationship of radiation dose to various biological effects or outcomes and the resulting estimates of risk, but not specify dose limits. This would relieve the NCRP of the necessity to speculate about acceptable risks. One can also imagine that the principle of justification could be applied not only to the introduction of a new source of radiation, but also to the removal of an existing source of radiation, i.e., the idea of justifying decontamination efforts. It is clear that as we move into the 21st century there will be a continuing need for the NCRP to identify the principles upon which radiation protection is to be based and to provide guidance on the application of those principles for the many beneficial uses of radiation and radioactive materials in society.

Two decades of radiological accidents direct causes, roots causes and consequences

Practically all Countries utilize radioisotopes in medicine, industry, agriculture and research. The extent to which ionizing radiation practices are employed varies considerably, depending largely upon social and economic conditions and the level of technical skills available in the country. An overview of the majority of practices and the associated hazards will be found in the <A HREF="#tabela4">Table IV</A> to <A HREF="#tabela7">VII</A> of this document. The practices in normal and abnormal operating conditions should follow the basic principles of radiation protection and the Safety of Radiation Sources, considering the IAEA Radiation Protection and the Safety of Radiation Sources, Safety Series 120 and the IAEA Recommendation of the Basic Safety Standards for Radiation Protection, Safety Series Nº 115. The Standards themselves underline the necessity to be able to predict the radiological consequences of emergency conditions and the investigations that should need to be done. This paper describes the major accidents that had happened in the last two decades, provides a methodology for analyses and gives a collection of lessons learned. This will help the Regulatory Authority to review the reasons of vulnerabilities, and to start a Radiation safety and Security Programme to introduce measurescapable to avoid the recurrence of similar events. Although a number of accidents with fatalities have caught the attention of the public in recent year, a safety record has accompanied the widespread use of radiation sources. However, the fact that accidents are uncommon should not give grounds for complacency. No radiological accident is acceptable. From a radiation safety and security of the sources standpoint, accident investigation is necessary to determine what happened, why, when, where and how it occurred and who was (were) involved and responsible. The investigation conclusion is an important process toward alertness and feedback to avoid careless attitudes by improving the comprehension of Safety Performance and Safety Culture. Accident investigation is the first step toward avoiding future injures and financial losses, by prevention of recur recurrence. On the other hand, accident investigation is also essential for the establishment of the responsibilities and liability for the consequences. This document discuss the main accidents that have happened in the last two decades, in terms of causes, consequences, similarities and lessons learned when sealed sources have been damaged, lost, stolen and abandoned. In considerable majority death and serious injuries were resulted from failures in the safety system for radiation sources and for the security of radioactive materials.

Do surgical residents, emergency medicine physicians, and nurses experience significant radiation exposure during the resuscitation of trauma patients?

During this study we investigated the yearly risk of radiation exposure for surgical residents (group 1, n = 8), emergency department (ED) physicians (group 2, n = 6) and nurses (group 3, n = 97) participating in the resuscitation of trauma victims in the emergency department of a 500-bed teaching hospital. Dosimeter readings of the three study groups were recorded monthly over the 1-year study period. During the study interval, 758 patients underwent resuscitation following trauma; 2098 portable radiographs (758 chest films, 758 lateral cervical spine films, and 582 radiographs of the pelvis) were obtained during the resuscitation phase of these patients. The total radiation exposure for group 3 was significantly greater than that for groups 1 and 2 (340 +/- 50 vs. 160 +/- 112 and 20 +/- 14 mrem, respectively, p < 0.01). Individual residents received a significantly greater amount of radiation than ED physicians and nurses (20 +/- 28 vs. 3.3 +/- 2.0 and 3.5 +/- 2.0 mrem, respectively, p < 0.05). However, despite repeated exposure to radiation, individuals in the three groups did not exceed the safety limits of 0.05 Gy/year set by the National Council on Radiation Protection and Measurements. Based on the results of this study, we conclude that trauma resuscitation teams can provide quality care to their patients without concern over the detrimental effects of radiation exposure, provided that the basic principles of radiation protection are followed.

Some notes on the administration of atomic cocktails.

A DECADE of uninterrupted experience has given us an appreciation of several obvious but correctable errors incident to the administration of therapeutic doses of radioactive materials. Adherence to the basic principles of radiation protection often will aid in minimizing exposure of personnel during and after administration of radioactive isotopes. Radiation protection, in the main, is governed by 3 factors: 1. Distance, wherein intensity varies according to the inverse square law. 2. Time, wherein the longer the interval in a radiation field, the greater the exposure. 3. Shielding, wherein materials such as lead, copper, steel and others, in adequately chosen thicknesses, will attenuate radiation to a permissible level. To illustrate some common errors, the following experiences are presented. Examples of Incorrect Administration of Radioactive Materials Example 1.— A physicist was asked to investigate a series of film badge exposures with levels of radiation above the accepted range for the usual work

Development of the basic principles of radiation protection and its significance for the coming first radiation protection ordinance

Drug Prescribing for Patients with Chronic Kidney Disease in General Practice: a Cross-Sectional Study