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PET(正电子发射成像)是当今高层次的核医学技术。它综合了核技术、核电子学、计算机、数据处理等领域中的尖端技术,是当前医学界最先进的大型医疗诊断成像设备之一,在肿瘤、心血管疾病和神经系统疾病的临床诊断中发挥着越来越重要的作用。本文以国产32环高档临床PET为例,较详细地介绍了PET设备的工作原理、总体基本结构及各子系统基本功能,对PET整机性能及其临床应用也做了简述。 相似文献
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正电子发射计算机断层成像技术（PET）是一种基于功能改变的显像技术,能够通过特定的示踪剂在体内的分布特点来反映体内某方面的功能代谢水平。近年来,PET诊断得到了越来越多的临床认可,其显像系统也发展迅速,多种功能PET仪器相继推出,2017年国内推出了全球首台全景动态扫描PET/CT（轴向视场为196.6 cm）。本文将对近年来PET/CT的技术发展和全景动态扫描PET/CT研究突破进行相关综述。 相似文献
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本文介绍1例罕见的发生于鼻咽部的颈部坏死性筋膜炎（CNF）。该患者以顽固性慢性化脓性中耳炎就诊,进行包括CT、MRI及PET/CT在内的影像学检查,均误诊为鼻咽癌。最终该患者通过鼻咽肿物活检术确诊为CNF。本文通过回顾性分析该患者的影像学表现及误诊原因,总结出CT、MRI、PET/CT在CNF早期诊断中的特征和要点,为其临床精准诊断提供重要的帮助。 相似文献
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SPECT/CT是继PET/CT之后迅速推出的新型分子影像设备。它利用单光子核素,并借助CT的功能,同时能提供脏器、组织精细的形态解剖和功能代谢信息,为疾病的定位和定性诊断提供客观依据。与PET、PET/CT相比更具有普及、推广和广泛开展临床应用的实用价值,是一种新的分子影像技术。 相似文献
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PET/CT新技术应用 总被引：3，自引：2，他引：1
王荣福 《CT理论与应用研究》2009,18(4)
PET/CT将PET与CT整合为一体化,是功能显像和解剖显像的有机结合.为了获取经济效益,PET/CT必须在不增加治疗费用的同时具有精确的诊断性,并对患者的治疗方案作出有效的指导.PET/CT由于采用了3D采集与单纯PET相比缩短了图像采集时间,从而使病人的要求得到更大程度的满足,同时也增加了病人的舒适程度,减少了由于采集过程中病人活动导致的出错机率.PET/CT在临床上主要应用于肿瘤学、心脏病学及神经精神医学等领域,在上述领域的中其诊断精确性优势是其他显像方法不可比拟的.在指导肿瘤治疗方面,PET/CT可以通过改善患者的治疗决策而具有重要的卫生经济学价值. 相似文献
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新型冠状病毒肺炎已在全世界多个国家暴发,如何提升早期筛查率成为疫情防控的重点。计算机断层扫描（CT）在中国新冠肺炎的早期筛查及疾病监测中发挥了重要作用,因此,提升广大影像医生对肺炎诊断的准确性尤其重要。本文旨在述评CT在新冠肺炎筛查中的应用价值、诊断及鉴别诊断要点,比较新冠肺炎与其他病毒性肺炎、细菌性肺炎等的CT表现差别,以期在今后的疫情防控中CT可以发挥更好的作用,帮助即早发现并隔离病患。 相似文献
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概述：PACS（PictureArchivingandCommunicationSystems）即图像归档与传输系统,是医院的医学图像信息管理系统,图像主要来源于医院的放射医疗设备（如X-CT、UFCT、MAI机以及PET等）。传统的放射科医生的诊断方式主要是根据由特定影像设备产生的胶片,凭借医生多年的诊断经验判断是否有病变及其具体情况。这种利用胶片的诊断和存储方式随着影像设备的不断更新换代已经越来越不适应医院的管理发展需要。随着计算机技术的飞速发展,使用计算机取代胶片保存手段应用于医院管理的想法已产生了,PACS正是这种思想发展的结果。PACS… 相似文献
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正常脑老化进程中脑局部葡萄糖代谢减低的规律 总被引：1，自引：0，他引：1
目的:利用统计参数图(SPM)分析正常人脑PET图像,研究正常脑老化进程中脑局部葡萄糖代谢减低的规律.方法:将266例(21～87岁)健康体检者的PET脑图像,按年龄以10岁为一个年龄段,分成7个组.在Matlab平台上用SPM2软件对7个组中每相邻两组进行组间分析,并以20～29岁组作为基准,其他各年龄组分别与该基准组进行比较,设统计学检验显著性阈值P为0.001.结果:SPM分析显示:①随着年龄的增长,全脑代谢减低区范围逐渐扩大,且程度逐渐加重,于70～79岁时达到高峰,80岁以后代谢减低进程有所减慢;②随着年龄的增长,不同脑区出现代谢减低的时间段不同:40岁之前未见明显代谢减低区;40～49岁仅有左侧额叶出现很小范围的代谢减低,是最先出现代谢减低的脑区;50～59岁右侧额叶、右侧顶叶和前扣带回出现代谢减低;60～69岁双侧顶叶和尾状核出现代谢减低;③随着年龄的增长,不同脑区代谢减低的程度不同:按程度由高到低依次为双侧额叶、前扣带回、双侧顶叶、尾状核头、双侧颞叶及小脑;④各年龄段均未见双侧枕叶、后扣带回、壳核和丘脑出现代谢减低.结论:脑老化进程中,正常人脑葡萄糖代谢减低的程度和范围与年龄呈正相关;不同脑区出现代谢减低的时间段不同,左侧额叶是最早出现代谢减低的脑区;不同脑区代谢减低的程度不同, 其中以双侧额叶及前扣带回代谢减低最为明显. 相似文献
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遥感技术在我国矿产资源预测评价中的应用 总被引：6，自引：7，他引：6
遥感技术作为有效的辅助手段应用于矿产资源预测已有多年历史.随着遥感技术的发展，遥感技术的作用将会变得越来越重要.本文综合叙述了遥感技术在资源预测评价中的应用现状以及应用方法，并对将来遥感技术在资源预测中的应用前景进行了展望. 相似文献
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随着SAR遥感应用越来越广,数据源的可选性越来越多,如何选取合适SAR数据源至关重要.本文分析了SAR影像回波强度影响因素,在此基础上从卫星拍摄飞行方向、入射角、波长、极化类型、产品类型等参数选择方面进行论述,从而得到SAR卫星数据用于高山峡谷区地质灾害形变监测时的参数选择方案,最终达到保证数据源质量,保障监测效果的目的.本文研究内容对采用SAR遥感数据源进行地质灾害的早期识别与动态监测选用合适数据源提供技术支持,并具有重要的参考价值. 相似文献
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《国际泥沙研究》2014,(4)
正Director:Shangfu Kuang,China Vice-directors:Chunhong Hu,China Duihu Ning,China Guangquan Liu,China The International Research and Training Center on Erosion and Sedimentation(IRTCES)was jointly set up by the Government of China and UNESCO on July 21,1984.It aims at the promotion of international exchange of knowledge and cooperation in the studies of erosion and 相似文献
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《中国科学:地球科学(英文版)》2014,(3)
正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research. 相似文献
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Richard D. Hey 《地球表面变化过程与地形》1979,4(1):59-72
Feedback mechanisms, which operate upstream through drawdown and backwater effects and downstream through sediment discharge are responsible for channel evolution. By combining these mechanisms with channel processes it euables a dynamic process-response model to be developed to simulate the initial evolution of straight gravel-bed channels. When erosion commences on a land surface, sediment entrained in the headwater reach by hydraulic action is selectively transported, deposited and reworked. This produces a damped oscillation between degradation and aggradation as the channel and valley respond to spatial and temporal variations in sediment calibre and hydraulic conditions. The initial cut and fill phases are responsible for valley incision and floodplain development while secondary and subsequent activity can produce river terraces. Eventually sediment entrainment in the headwaters declines as slopes are reduced. Subsequent channel evolution is relatively insignificant because it is dependent on local weathering activity producing material that can be transported on declining slopes. Therefore landforms produced during the initial phase of development, when local weathering was non-limiting, dominate the landscape. 相似文献
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Based on relocating the Jiujiang-Ruichang earthquake sequence which occurred on November 26, 2005 in Jiangxi Province with the double-difference （DD） algorithm and master event technique, the paper discusses the focal mechanism of the main shock （MsS.7） and the probable seismo-tectonics. The precise relocation results indicate that the average horizontal error is 0.31kin in a EW direction and 0.40kin in a NS direction, and the average depth error is 0.48kin. The focal depths vary from 8kin to 14kin, with the predominant distribution at 10kin - 12kin. The epicenter of the main shock is relocated to be 29.69^oN, 115.74^oE and the focal depth is about 10.Skin. Combining the predominant distribution of the earthquake sequence, the focal mechanism of the main shock and the tectonic conditions of N-E- and NW-strike faults growth in the seismic region, we infer that the main shock of the earthquake sequence was caused by a NW striking buried fault in the Rnichang basin. The nature of seismic faults needs to be further explored. 相似文献
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《水文科学杂志》2013,58(6)
Abstract The western reservoirs represent the principal groundwater system in Morocco. Demographic, industrial and agricultural developments during the last decade have markedly altered groundwater quality. The Mamora coastal aquifer system is among the Atlantic systems which are most heavily threatened by pollution. Agricultural and industrial activities, and rapid urban growth contribute to the pollution of the groundwater. Contamination transport is facilitated by a high permeability of the aquifer formations. In order to assess the actual groundwater quality of the Mamora aquifer and to understand the influence of the factors generating the pollution, an extensive multidisciplinary research programme is in progress, with hydrochemistry and microbiology playing essential roles. The present paper concerns the spatial distribution of physico-chemical parameters in the groundwater, subjected to domestic, industrial and agricultural pollution. Fifty-seven samples were analysed for several parameters (Ca2+, Mg2+, Na+, K+, Cl?, SO4 2?, HCO3 ?, NO3 ?, pH, electrical conductivity and temperature). The microbiological analysis of 143 samples reveals the presence of four kinds of indicator bacteria in the groundwater resources: faecal Streptococci, faecal coliform, Escherichia coli and Clostridium. The physico-chemical results and bacteriological monitoring show that the nitrate and bacteria concentrations exceed the maximum admissible levels, notably around pumping stations in the sectors of Sidi Taibi, Sidi Ahmed Taleb and Aïn Sbaâ. Contamination is generated by uncontrolled anthropogenic activities and accentuated by the high intrinsic vulnerability of the aquifer system. Several parameters appeared to exceed admissibility standards. Measures are recommended to prevent groundwater pollution in the region. 相似文献
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《中国科学:地球科学(英文版)》2014,(12)
正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research. 相似文献