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- 摘要
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- 实验方案
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Imaging Considerations in Pregnancy
摘要： Pregnancy is a complex interplay of multiple physiologic states maintaining balance between the needs of mother and fetus. This is reflected in hormonal, hemodynamic, hematologic, and immunologic changes at both global and cellular levels. A decrease in brain size and increase in heart, pituitary, thyroid, and kidney sizes secondary to hormonal influences have been observed during pregnancy.1,2 Circulating hormones also have trophic effect on preexisting neoplasms, such as meningioma, pituitary adenomas, and breast carcinoma.3 The increased blood volume and clotting factor alterations increase the risk of stroke, especially during the peripartum and postpartum period.4,5 Hemodynamic and hormonal effects on vessel wall integrity can lead to worsening of aneurysm with possible hemorrhage, whereas prolonged labor may increase risk of infarct from venous thrombosis or dissection.6,7 In contrast, increased cortisol levels have shown to improve autoimmune diseases such as multiple sclerosis by exerting inhibitory effect on T-cell function8–10
关键词： Radiation safety,Pregnancy,Imaging,RCVS,Stroke,PRES,Eclampsia
更新于2025-09-23 15:21:21
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Radiology, Lasers, Nanoparticles and Prosthetics || 2. Nuclei and isotopes
摘要： In Chapters 5 to 12 nuclear methods in medicine are discussed either for imaging (scintigraphy, SPECT, PET) or for radiation treatment of cancerous tissues (proton and neutron irradiation, brachytherapy). It is therefore appropriate to first introduce some basic properties of nuclides and isotopes, and in particular of radioactive isotopes which are used in nuclear medicine. This chapter is not intended to replace a textbook on nuclear physics. But it provides sufficient background information for better understanding the subsequent chapters. Handling of radiation in general and application of radioactive isotopes also requires a detailed knowledge of radiation dose and radiation safety, which are topics of Chapter 4.
关键词： scintigraphy,medicine,SPECT,neutron irradiation,PET,brachytherapy,radiation safety,proton irradiation,nuclides,cancerous tissues,isotopes,radioactive isotopes,radiation dose,imaging,nuclear medicine,nuclear methods,radiation treatment
更新于2025-09-19 17:13:59
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21.1: <i>Invited Paper:</i> Optical Radiation Safety Analysis for Laser Used as Illumination Products
摘要： Illumination products using laser source have plenty of advantages, such as high conversion efficiency, more brightness, wide color gamut, long life and so on. However, due to the high energy density of laser, the optical radiation safety of laser used as illumination products should be studied and analyzed. First of all, the characteristics, advantages of laser used as illumination products are introduced. Then the international and national organizations, such as IEC/TC 76, IEC/TC 108, SAC/TC 284, are surveyed. In addition, standards and the corresponding relations related to laser used as illumination products are reviewed, especially for safety of laser products (IEC 60825) series standards, photobiological safety of lamps and lamp systems (IEC 62741) series standards, Audio/video, information and communication technology equipment–Part 1: Safety requirements (IEC 62368-1:2018), as well as ICNIRP guidelines. Finally, optical radiation safety of some specific illumination products using lasers are discussed.
关键词： optical radiation safety,laser illumination,laser display,laser source
更新于2025-09-11 14:15:04
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Analyses of optical radiation safety standards for laser illuminated products
摘要： The high energy density of optical radiation from laser illuminated products may cause eye injury, so it is necessary to study the optical radiation safety standards for these products. The relations of related international and Chinese organizations, such as IEC/TC76, IEC/TC108, IEC/TC110, Chinese technical committee SAC/TC284, and so on, are introduced. The related standards and the relations are surveyed, especially the safety of laser products (IEC 60825) series, the photobiological safety of lamps and lamp systems (IEC 62741) series, and audio/video, information and communication technology equipment—part 1: safety requirements (IEC 62368‐1:2018). As application examples of standards, some specific laser illuminated products, including the laser projector, the laser headlamp and light detection and ranging (LiDAR) used in the vehicle, as well as the evaluation methods for the blue light effect of the display are discussed and analyzed. On the basis of the analyses of the optical radiation safety standards, it is necessary to select or develop appropriate standards for different types of laser illuminated products.
关键词： optical radiation safety,laser illuminated product
更新于2025-09-11 14:15:04
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Simultaneous measurement of patient dose and distribution of indoor scattered radiation during digital breast tomosynthesis
摘要： Introduction: Breast cancer incidence increases from the age of 30 years. As this age range coincides with that in which women usually pursue pregnancy, undergoing medical examinations for conditions such as breast cancer is a concern, especially when pregnancy is uncertain during the first eight weeks. Moreover, in this age range, breast often exhibits a high density, thus compromising diagnosis. For such density, digital breast tomosynthesis (DBT) provides a more accurate diagnosis than 2D mammography given its higher sensitivity and specificity. However, radiation exposure increases during DBT, and it should be determined. Methods: We determined the entrance surface dose, scattered radiation dose, and average glandular dose (AGD), which can be mutually compared following an international protocol. Using our proposed method, the distribution of scattered radiation can be easily and quickly obtained with a minor load to the equipment. Then, we can determine the indoor scattered radiation and surface dose on patients during DBT. Results: We obtained a maximum AGD of 2.32 mGy. The scattered radiation was distributed over both sides with maximum of approximately 40 mGy, whereas the maximum dose around the eye was approximately 10 mGy. Conclusion: By measuring doses using the proposed method, a correct dose information can be provided for patients to mitigate their concerns about radiation exposure. Although the obtained doses were low, their proper management is still required. Overall, the results from this study can help to enhance dose management for patients and safety management regarding indoor radiation.
关键词： Radiation safety,Entrance surface dose,Jungle gym method,Scatter dose,Digital breast tomosynthesis,Average glandular dose (AGD)
更新于2025-09-10 09:29:36