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ValueofDigitalX—RayPhotographyinDiagnosisofCongenitalHeartDisease 被引量:5
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作者 侯建新 李光民 《中国全科医学》 CAS CSCD 北大核心 2011年第24期2821-2822,共2页
目的探讨数字化X线摄影在先天性心脏病诊断中的应用价值。方法收集我院2009-01-01—10-31经数字化X线摄影检查阳性并经临床随访或手术证实的先天性心脏病患者97例,对其临床及影像学资料进行回顾性分析。结果 97例患者中,房间隔缺损46例... 目的探讨数字化X线摄影在先天性心脏病诊断中的应用价值。方法收集我院2009-01-01—10-31经数字化X线摄影检查阳性并经临床随访或手术证实的先天性心脏病患者97例,对其临床及影像学资料进行回顾性分析。结果 97例患者中,房间隔缺损46例(47.4%),动脉导管未闭17例(17.5%),室间隔缺损13例(13.4%),法洛四联症5例(5.2%),肺动脉瓣狭窄3例(3.1%),镜面右位心4例(4.1%),右位主动脉弓7例(7.2%),其他复杂畸形2例(2.1%)。X线表现为:肺血增多、肺血减少及心影形态失常。结论数字化X线摄影准备简单、安全、快捷,禁忌证少,整体感强,同时还是术后随访的重要检查手段,目前仍然能够为先天性心脏病的诊断提供独特和有价值的信息。 展开更多
关键词 数字化X线摄影 先天性心脏病 诊断
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Full-field mapping of internal strain distribution in red sandstone specimen under compression using digital volumetric speckle photography and X-ray computed tomography 被引量:5
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作者 Lingtao Mao Jianping Zuo +1 位作者 Zexun Yuan Fu-Pen Chiang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2015年第2期136-146,共11页
It is always desirable to know the interior deformation pattern when a rock is subjected to mechanicalload. Few experimental techniques exist that can represent full-field three-dimensional (3D) straindistribution i... It is always desirable to know the interior deformation pattern when a rock is subjected to mechanicalload. Few experimental techniques exist that can represent full-field three-dimensional (3D) straindistribution inside a rock specimen. And yet it is crucial that this information is available for fully understandingthe failure mechanism of rocks or other geomaterials. In this study, by using the newlydeveloped digital volumetric speckle photography (DVSP) technique in conjunction with X-ray computedtomography (CT) and taking advantage of natural 3D speckles formed inside the rock due to materialimpurities and voids, we can probe the interior of a rock to map its deformation pattern under load andshed light on its failure mechanism. We apply this technique to the analysis of a red sandstone specimenunder increasing uniaxial compressive load applied incrementally. The full-field 3D displacement fieldsare obtained in the specimen as a function of the load, from which both the volumetric and the deviatoricstrain fields are calculated. Strain localization zones which lead to the eventual failure of the rock areidentified. The results indicate that both shear and tension are contributing factors to the failuremechanism. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved. 展开更多
关键词 Red sandstone Strain localization Uniaxial compression digital volumetric speckle photography(DVSP) X-ray micro-tomography
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A Model for Estimating Total Forest Coverage with Ground-Based Digital Photography 被引量:5
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作者 GU Zhu-Jun ZENG Zhi-Yuan +5 位作者 SHI Xue-Zheng LI Lin D. C. WEINDORF ZHA Yong YU Dong-Sheng LIU YongoMei 《Pedosphere》 SCIE CAS CSCD 2010年第3期318-325,共8页
Vegetation fractional coverage (VFC) is one of the key indicators of vegetation distribution. In the work a measurement-based model was developed to derive total forest VFC (TG) as well as the VFC of trees (T) and shr... Vegetation fractional coverage (VFC) is one of the key indicators of vegetation distribution. In the work a measurement-based model was developed to derive total forest VFC (TG) as well as the VFC of trees (T) and shrub-grasses (G) separately in a subtropical forest area in Nanjing, China. Both upward and downward photographs were taken with a digital camera in 72 quadrats (10 m × 10 m each). Fifteen models were established and validated. Models jointly using both T and G performed better than those using the T and G separately. The best model, TG = T + G- 1.134 × T × G- 0.025 (R2 = 0.9115, P < 0.01, root mean squared error = 0.0789), is recommended for application. This model provides a good way to obtain total forest VFC values through taking tree and shrub-grass photos on ground below tree canopy rather than above tree canopy. 展开更多
关键词 digital camera 2-layer photography shrub-grasses trees
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Application Strategies of Spatial Refinement Design in Ancient Cities Supported by Digital Te-Zhaoyu Ancient City in Qixian County as an Example
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作者 BAI Zhao-yi FANG Yu-xin WEN Jia-hao 《Journal of Literature and Art Studies》 2024年第6期474-490,共17页
Digital technology provides a method of quantitative investigation and data analysis for contemporary landscape spatial analysis,and related research is moving from image recognition to digital algorithmic analysis,pr... Digital technology provides a method of quantitative investigation and data analysis for contemporary landscape spatial analysis,and related research is moving from image recognition to digital algorithmic analysis,providing a more scientific and macroscopic way of research.The key to refinement design is to refine the spatial design process and the spatial improvement strategy system.Taking the ancient city of Zhaoyu in Qixian County,Shanxi Province as an example,(1)based on obtaining the integrated data of the ancient city through the drone tilt photography,the style and landscape of the ancient city are modeled;(2)the point cloud data with spatial information is imported into the point cloud analysis platform and the data analysis is carried out from the overall macroscopic style of the ancient city to the refinement level,which results in the formation of a more intuitive landscape design scheme,thus improving the precision and practicability of the landscape design;(3)Based on spatial big data,it starts from the spatial aggregation level,spatial distribution characteristics and other evaluation index system to achieve the refinement analysis of the site.Digital technology and methods are used throughout the process to explore the refined design path. 展开更多
关键词 digital technology Zhaoyu Ancient City tilt photography point cloud data
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Evaluation of Diagnostic Efficacy of Digital Subtraction Radiography in the Diagnosis of Simulated External Root Resorption: An <i>in Vitro</i>Study
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作者 Nasim Mokhtari Goorabjavari Ahmadreza Talaeipour +2 位作者 Fatemeh Ezoddini-Ardakani Yaser Safi Nafiseh Shamloo 《Health》 2015年第4期439-448,共10页
External root resorption can induce the degeneration of dental cementum and dentine and may extend towards the pulp reductive. Digital subtraction radiography can function as a useful tool in diagnosing degenerative c... External root resorption can induce the degeneration of dental cementum and dentine and may extend towards the pulp reductive. Digital subtraction radiography can function as a useful tool in diagnosing degenerative carious lesions. This study investigated the diagnostic value of digital subtraction radiography in detecting external root resorption. This was a descriptive study conducted using the lab trial method. Artificially-induced external root resorption was created in different sizes at the coronal and apical aspects of 20 premolar teeth. Digital radiographs were obtained of each tooth under standard conditions and these radiographs were subtracted by imaging devices. The subtracted images and the digital radiographs were observed by three radiologists. Chi-square, Kappa test, and Z-test were used to analyze the data. The mean of general sensitivity of digital subtraction radiography and direct digital radiography was low in diagnosing 0.05 mm lesions (Sen = 35%), yet, the accuracy index was good for all lesions (Acc ≥ 65%). Other diagnostic parameters were also acceptable. Both types of radiography worked better in diagnosing coronal than apical lesions (P > 0.05). The interpreters (observers) showed a better performance in diagnosing external root resorption using digital subtraction radiography compared to digital radiography. Both modalities were exact and accurate in detecting 0.05 mm lesions as well as other lesions. However, the results of digital subtraction radiography were not significantly different from those of direct digital radiography. 展开更多
关键词 SUBTRACTION radiography radiography Direct digital radiography External ROOT RESORPTION
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Evaluation of Positive Predictive Value for Digital Panoramic Radiography in Comparison to Ultrasound in the Diagnosis of Calcified Carotid Atheroma
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作者 Fatemeh Ezoddini-Ardakani Maryam Mirzaei +2 位作者 Saman Nayer Sajad Besharati Malihe Moeini 《Health》 2014年第15期1933-1940,共8页
Aim: Detection of calcified carotid atheroma (CCA) has an important role in reducing the incidence of Cerebro Vascular Accident (CVA). The aim of this study was to evaluate efficacy of panoramic digital radiography in... Aim: Detection of calcified carotid atheroma (CCA) has an important role in reducing the incidence of Cerebro Vascular Accident (CVA). The aim of this study was to evaluate efficacy of panoramic digital radiography in detecting atherosclerosis. Methods: It is descriptive-analytical diagnostic study. The people (22 to 62 years old) were referred to a radiology clinic to perform panoramic radiography for diagnosis of CCA. Individuals who were suspected were introduced to the radiology department of dental school to undergo ultrasound evaluation to CCA. For the 41 patients (55 sides), ultrasound was performed. For data analysis, the Chi-square and Fisher's exact test were used. Results: The prevalence of CCA was 2.43%. The PPV of digital panoramic was 45.5%. There was no significant relationship between age (P = 0.14) and sex (P = 0.539) and PPV of digital panoramic. The PPV of digital panoramic was significantly associated with hypertension (P = 0.032). Conclusion: It seems that panoramic can be used to screen patients with a history of hypertension for atherosclerosis. 展开更多
关键词 radiography PANORAMIC digital ULTRASONOGRAPHY Atherosclerosis
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Comparison via Digital Radiography of Radiopacity Levels of Composite Materials with Various Shades and Viscosities
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作者 Gunce Ozan Oktay Yazicioglu +1 位作者 Hidir Tatar Sevda Ozel Yildiz 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2022年第2期170-176,共7页
Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An a... Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An aluminum step wedge ranging from 2.0 to 10.0 mm in thickness was placed on the occlusal film.Digital radiographs were taken using a dental X-ray device and radiographic densities of each step of the aluminum wedge and the samples were recorded to the computer.Five readings were taken and means were calculated.One-Way Anova and Tamhane post hoc tests were performed.While G-eanial Posterior has the highest radiopacity value followed by Filtek Z550,Aelite Flo has the lowest radiopacity value.Posterior composites show higher radiopacity and flowable composites with higher filler loadings have superior radiopacity levels to condensable composites.Enamel and body shades of the composite brands have also statistically significant differences in radiopacity scores.Eventually,radiopacity level of a composite resin material is not affected by the size of fillers;however,the composition,shape and loading of the fillers can specify the radiodensity. 展开更多
关键词 RADIOPACITY composite resins digital radiography flowable composites SHADE
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Evaluation of Entrance Skin Radiation Exposure Dose for Pediatrics Examined by Digital Radiography at Asser Central Hospital-KSA
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作者 Sami Nasreldein Abdelwally Eljak Caroline Edward Ayad Elsafi Ahmed Abdalla 《Open Journal of Radiology》 2015年第3期125-130,共6页
Assessment of entrance skin doses for patients in Digital radiography examinations should be made as a means for the optimization of the radiation protection of the patients. We measured the entrance skin dose (ESD) r... Assessment of entrance skin doses for patients in Digital radiography examinations should be made as a means for the optimization of the radiation protection of the patients. We measured the entrance skin dose (ESD) received by 50 pediatrics undergoing 12 types of diagnostic X-ray examination at Radiology Department of Asser Central Hospital-KSA. The entrance skin dose ESD was determined via measurements parameters: focus to skin distance (FSD), tube current (mAs) and tube voltage (kV) in arithmetical equation. The mean ± SD for ESDs were found to be 0.16 ± 0.03, 0.21 ± 0.01, 0.63 ± 0.26, 0.55 ± 0.09, 0.15 ± 0.05, 0.27 ± 0.06, 0.41 ± 0.19, 0.46 ± 0.18, 0.46 ± 0.12, 0.20 ± 0.02, 0.39 ± 0.01, 0.29 ± 0.03, for PA chest, foot, AP pelvis, PA skull, PA hand, AP arm, ankle, AP shoulder, abdomen, forearm, AP femur, AP elbow consequently. Our study is considered as an attempt to evaluate the ESDs received by digital radiographic x-ray machine for children aged between 2 - 15 years old, taking in our considerations number of other variables. The mean ESD values obtained are found to be within the standard reference. The data obtained may add to the available information in national records for general use. It may provide guidance on where efforts on dose reduction will need to be directed to fulfill the requirements of the optimization process and serve as a reference for future researches. 展开更多
关键词 ENTRANCE SKIN DOSE PEDIATRICS digital radiography
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Evaluating the impact of sampling schemes on leaf area index measurements from digital hemispherical photography in Larix principis-rupprechtii forest plots
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作者 Jie Zou Wei Hou +5 位作者 Ling Chen Qianfeng Wang Peihong Zhong Yong Zuo Shezhou Luo Peng Leng 《Forest Ecosystems》 SCIE CSCD 2020年第4期686-703,共18页
Background:Digital hemispherical photography(DHP)is widely used to estimate the leaf area index(LAI)of forest plots due to its advantages of high efficiency and low cost.A crucial step in the LAI estimation of forest ... Background:Digital hemispherical photography(DHP)is widely used to estimate the leaf area index(LAI)of forest plots due to its advantages of high efficiency and low cost.A crucial step in the LAI estimation of forest plots via DHP is choosing a sampling scheme.However,various sampling schemes involving DHP have been used for the LAI estimation of forest plots.To date,the impact of sampling schemes on LAI estimation from DHP has not been comprehensively investigated.Methods:In this study,13 commonly used sampling schemes which belong to five sampling types(i.e.dispersed,square,cross,transect and circle)were adopted in the LAI estimation of five Larix principis-rupprechtii plots(25m×25 m).An additional sampling scheme(with a sample size of 89)was generated on the basis of all the sample points of the 13 sampling schemes.Three typical inversion models and four canopy element clumping index(Ωe)algorithms were involved in the LAI estimation.The impacts of the sampling schemes on four variables,including gap fraction,Ωe,effective plant area index(PAIe)and LAI estimation from DHP were analysed.The LAI estimates obtained with different sampling schemes were then compared with those obtained from litter collection measurements.Results:Large differences were observed for all four variable estimates(i.e.gap fraction,Ωe,PAIe and LAI)under different sampling schemes.The differences in impact of sampling schemes on LAI estimation were not obvious for the three inversion models,if the fourΩe algorithms,except for the traditional gap-size analysis algorithm were adopted in the estimation.The accuracy of LAI estimation was not always improved with an increase in sample size.Moreover,results indicated that with the appropriate inversion model,Ωe algorithm and sampling scheme,the maximum estimation error of DHP-estimated LAI at elementary sampling unit can be less than 20%,which is required by the global climate observing system,except in forest plots with extremely large LAI values(~>6.0).However,obtaining an LAI from DHP with an estimation error lower than 5%is impossible regardless of which combination of inversion model,Ωe algorithm and sampling scheme is used.Conclusion:The LAI estimation of L.principis-rupprechtii forests from DHP was largely affected by the sampling schemes adopted in the estimation.Thus,the sampling scheme should be seriously considered in the LAI estimation.One square and two transect sampling schemes(with sample sizes ranging from 3 to 9)were recommended to be used to estimate the LAI of L.principis-rupprechtii forests with the smallest mean relative error(MRE).By contrast,three cross and one dispersed sampling schemes were identified to provide LAI estimates with relatively large MREs. 展开更多
关键词 Sampling scheme Elementary sampling unit Clumping index Leaf area index digital hemispherical photography FOREST LARIX
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Comparative Study of Radiological Changes in Hands and Feet in Patients Suffering from Early Rheumatoid Arthritis by Power Doppler Ultrasound and Direct Digital Radiography
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作者 Gargy Mondal Biswadip Ghosh +1 位作者 Manoranjan Ghosh Pampa Halder 《Open Journal of Rheumatology and Autoimmune Diseases》 2014年第1期39-42,共4页
Rheumatoid arthritis is a chronic multisystem disease of unknown cause. The characteristic feature of RA is persistent inflammatory synovitis. The natural history of disease is such that the early months of the diseas... Rheumatoid arthritis is a chronic multisystem disease of unknown cause. The characteristic feature of RA is persistent inflammatory synovitis. The natural history of disease is such that the early months of the disease are critical period during which reversible joint damage occurs. So early diagnosis of RA and appropriate drug application is the only way to save a patient from this crippling disease. In India, the cost of investigations is a significant factor for most of the patients. Ultrasonography or Power Doppler Ultra Sound (PDUS) has the advantage of being economic in spite of its sensitivity in assessing both inflammatory and destructive changes. The aim of the present study was to evaluate the diagnostic efficiency of PDUS in early rheumatoid arthritis. The study was performed with the patients attending Rheumatology Clinic. A total number of 106 patients of clinically suspected rheumatoid arthritis were studied as per selection criteria. Radiological examinations of hands were done by digital radiography and PDUS in a group of 53 patients, assessment of foot changes by PDUS and Digital Radiography were done in another similar group of 53 patients. Final diagnosis by ACR EULAR-2010 criteria is done for all the patients. The comparative study reveals that synovial vascularity as demonstrated by PDUS is much more effective in diagnosing early rheumatoid arthritis, both in hand and in feet than digital radiograph. PDUS of feet may yield earlier and better findings than hands, which is conventionally used in patients suffering from early rheumatoid arthritis. 展开更多
关键词 R.A.—Rheumatoid Arthritis PDUS—Power Doppler Ultrasound D.R.—digital radiography ACR-EULAR—American College of RHEUMATOLOGY (ACR) and the European LEAGUE against RHEUMATISM (EULAR) RF—Rheumatoid Factor CRP—c-Reactive Protein MRI—Magnetic Resonance Imaging
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飞利浦Digital Diagnost系列DR设备工作原理及故障维修 被引量:3
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作者 黄亨杰 李均 +2 位作者 王吉鸣 陈斯尧 冯靖祎 《中国医院建筑与装备》 2019年第9期89-92,共4页
文章介绍了飞利浦Digital Diagnost系列DR设备工作原理和同步通讯信号传输时序,分析了X射线无法曝光、成像失败等故障的原因,有针对性地提出了处理措施,以期为同行提供相关经验。
关键词 数字化X射线成像系统 SAN信号传输 平板探测器 设备维修
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Photo Socialization in Digital Natives
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作者 Jacob Bafiuelos 《Journalism and Mass Communication》 2011年第3期226-234,共9页
In the following work of research, we shall present the results of a study on forms of digital photographic socialization as carried out by the so-called "digital natives" in order to explore their competence in man... In the following work of research, we shall present the results of a study on forms of digital photographic socialization as carried out by the so-called "digital natives" in order to explore their competence in managing digital photographic output and cultural practices. This shall be done under the following categories of analysis: snapshot, organization, socialization, reception, privacy, and copyrights in digital photography. The study explores the forms of digital photography production, technical problems of photographic management and the final uses that digital photographers give to their photos in terms of web tools 2.0, mobile telephones and social networks. Digital photography technology, compact cameras, mobile phones with cameras, specialized websites in photography and the lnternet generate new forms of production and emerging styles of digital photographic socialization. The study is carried out using a defined sample of university students, those digital natives who create and use digital photography. 展开更多
关键词 digital photography SOCIALIZATION digital photographic competency cultural practices digital natives
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Computer-Assisted DEM-Based Aero Photography Design 被引量:2
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作者 FAN Yewen GONG Jianya +1 位作者 TAN Chengguo WANG Ruiyao 《Geo-Spatial Information Science》 2008年第1期26-30,共5页
In aerial photography, the primary factor is terrain undulation. However, most of the external aerial photography software used for aerial photography design do not take terrain undulation influence into consideration... In aerial photography, the primary factor is terrain undulation. However, most of the external aerial photography software used for aerial photography design do not take terrain undulation influence into consideration. Therefore, the design result has comparative randomicity and "gaps" are expected. An aerial photography design system is developed by analyzing the terrain undulation influence to the design result with DEM data so that the forward overlap and side overlap can be justified according to the block terrain undulation to meet specifications or standards. The data designed by this system is compared with the real flying data. The results show that making use of DEM to assist in aerial photography design can ensure that the designed result fits the real terrain better. 展开更多
关键词 aerial photography design digital elevation model side overlaps forward overlaps
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THE APPLICATION OF FOURIER TRANSFORM IN REGULARIZED SPECKLE PHOTOGRAPHY
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作者 Zhang Yuanpeng Zhu Huaning Zhou Wenling 《Acta Mechanica Solida Sinica》 SCIE EI 2002年第1期75-80,共6页
Two speckle patterns are recorded using a video cameracorresponding to undisplaced and displaced states into the memory ofa computer. After one pattern is added to another, the displacementof the measured points can b... Two speckle patterns are recorded using a video cameracorresponding to undisplaced and displaced states into the memory ofa computer. After one pattern is added to another, the displacementof the measured points can be calculated by using the Fouriertransform. The expression of displacement field is deduced fornon-uniform displacement, and as an example, a rotatanle disc istested for illustration. The re- sults prove that the present methodis promising. 展开更多
关键词 speckle photography electronic speckle photography DFT digital imageprocessing
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DIP付费对医疗服务项目诊疗强度的影响研究 被引量:2
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作者 张爱玲 谭华伟 《卫生经济研究》 北大核心 2024年第7期41-43,48,共4页
目的:探索DIP付费对医疗服务项目诊疗强度的影响。方法:收集某市2020年1月至2022年12月330家医疗机构住院患者开展数字化摄影诊疗的数据,利用独立样本t检验比较诊疗强度的变化,采用间断时间序列分析考察DIP付费对诊疗强度的影响。结果:... 目的:探索DIP付费对医疗服务项目诊疗强度的影响。方法:收集某市2020年1月至2022年12月330家医疗机构住院患者开展数字化摄影诊疗的数据,利用独立样本t检验比较诊疗强度的变化,采用间断时间序列分析考察DIP付费对诊疗强度的影响。结果:DIP付费后三级医院、一级医院数字化摄影诊疗强度分别增加了0.03和0.04,二级医院下降了0.06;三级医院诊疗强度在短期内增加(β_(2)=0.061),长期却呈现下降趋势(β_(3)=-0.007)。结论:DIP付费对医疗服务项目诊疗强度的政策效应可能与政策预期不一致,异质性和同质性并存;要强化DIP支付方式改革与医疗服务价格改革的协同路径。 展开更多
关键词 DIP 数字化摄影 诊疗强度 政策效应
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飞利浦Digital DiagnostDigital 2.0双板DR运动单元结构及故障分析 被引量:1
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作者 王学兵 林俊伟 颜和平 《中国医疗器械信息》 2024年第3期169-172,共4页
数字X射线摄影技术在临床诊疗应用中占据重要作用,而数字X射线摄影设备作为目前医疗机构的基础医疗设备之一,具有操作简单,成像快捷,在用量大,使用频次较高的特点。为保障设备稳定可靠运行,需要临床工程人员熟悉设备构成、原理及操作流... 数字X射线摄影技术在临床诊疗应用中占据重要作用,而数字X射线摄影设备作为目前医疗机构的基础医疗设备之一,具有操作简单,成像快捷,在用量大,使用频次较高的特点。为保障设备稳定可靠运行,需要临床工程人员熟悉设备构成、原理及操作流程并能够做好日常质控和平时定期维护工作。工程人员应具备影像学及工程学等相关方面的知识,并能够着眼于日常及基础性维修工作,从中吸取教训,总结经验,保障设备正常稳定地运行,进而体现临床工程人员的价值,为医院临床工作保驾护航贡献自己的力量。 展开更多
关键词 数字X射线摄影 运动单元原理 常见故障
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数字断层融合摄影技术在股骨干骨折内固定术后的应用研究 被引量:1
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作者 王浩东 曾桔 +2 位作者 罗铧 代承忠 钟鉴 《中国CT和MRI杂志》 2024年第8期146-148,共3页
目的探讨数字断层融合摄影(DTS)在股骨干骨折内固定术后复查中的应用价值。方法收集90例股骨干骨折内固定术后患者,于术后6月时完成了数字化X线摄影(DR)及DTS检查。由两名放射科医师采用5分法对两种影像学检查方法所获图像进行图像质量... 目的探讨数字断层融合摄影(DTS)在股骨干骨折内固定术后复查中的应用价值。方法收集90例股骨干骨折内固定术后患者,于术后6月时完成了数字化X线摄影(DR)及DTS检查。由两名放射科医师采用5分法对两种影像学检查方法所获图像进行图像质量评价及对比。同时由临床医师对DTS及DR的骨折愈合显示率进行对比。结果术后6月时,DTS图像质量评分为(3.689±1.148)分,DR图像质量评分为(2.778±1.197)分,两组差异具有统计学意义(P<0.05)。DTS图像骨折愈合情况显示率为95.56%(86/90),DR图像骨折愈合情况显示率为72.23%(65/90),差异具有统计学意义(P<0.05)。结论在股骨干骨折内固定术后复查中,DTS能清晰显示术区骨质结构,准确判断骨折愈合情况,图像质量较DR更优,可作为股骨干骨折内固定术后复查较为理想的影像学检查方法,临床实用性较强。 展开更多
关键词 股骨干骨折内固定术 数字断层融合摄影 数字化X线摄影 图像质量
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基于不同数据源的数字孪生小流域底板模型精度检验
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作者 马良 樊冰 +3 位作者 吕爱霞 王松岳 武佳枚 牟强 《人民黄河》 CAS 北大核心 2024年第10期116-122,共7页
为解决小流域综合治理规划设计中基础地形数据获取困难等问题,基于合成孔径雷达卫星遥感影像、倾斜摄影影像、光探测测距影像等3种主流遥感数据源,分别建立栖龙湾小流域数字孪生底板模型,进而提取主沟道纵断面、2块梯田样地边界、10个... 为解决小流域综合治理规划设计中基础地形数据获取困难等问题,基于合成孔径雷达卫星遥感影像、倾斜摄影影像、光探测测距影像等3种主流遥感数据源,分别建立栖龙湾小流域数字孪生底板模型,进而提取主沟道纵断面、2块梯田样地边界、10个林地样区的郁闭度,与人工解译和实测结果对比进行精度检验,结果表明:以光探测测距影像为数据源的提取精度最高,以倾斜摄影影像为数据源的提取精度次之,以孔径雷达卫星遥感影像为数据源的提取精度最低。鉴于3种数据源小流域底板模型各有优缺点,可根据实际工作需要进行多源数据融合,以改善数字孪生技术在小流域综合治理规划设计中的应用效果。在栖龙湾小流域内选择石坎梯田地块进行合成孔径雷达卫星遥感影像与倾斜摄影影像数据融合、选择科普展览馆进行倾斜摄影影像与光探测测距影像数据融合,均取得良好的效果。 展开更多
关键词 数字孪生小流域 底板模型 数据源 合成孔径雷达 倾斜摄影 光探测测距 精度检验 数据融合
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基于数字孪生的烟田管理系统
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作者 詹莜国 李洪明 +3 位作者 李伟 杨兴党 麻莉娜 吕明站 《安徽农业科学》 CAS 2024年第12期222-227,共6页
烟草农业已通过实施设施农业和全程机械化等手段来提升烟叶的生产效率、烘烤烟草的品质以及农民的收益,但在烟田管理上仍然面临由非线性、互馈性、多尺度等难题带来的效率低下问题。采用数字孪生理论和技术,以昆明地区的烟田管理系统为... 烟草农业已通过实施设施农业和全程机械化等手段来提升烟叶的生产效率、烘烤烟草的品质以及农民的收益,但在烟田管理上仍然面临由非线性、互馈性、多尺度等难题带来的效率低下问题。采用数字孪生理论和技术,以昆明地区的烟田管理系统为研究对象,设计多要素物联网数据采集装置,结合无人机倾斜摄影技术,建立一种以虚控实的数字化在线推理和反馈体系的烟田数字模型,以烟草氮元素管理为实践应用,实现了数据驱动的烟田农事管理。结果表明,数字孪生技术能显著提升烟草农业的管理效率,其中氮元素管理服务效率提升71%。数字孪生技术在烟田管理的全过程中都有广泛的应用潜力,为烟草农业的数字化转型提供应用参考。 展开更多
关键词 数字孪生 烟田管理 虚拟模型 倾斜摄影 氮元素管理
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超广角视网膜激光扫描成像系统在DR筛查中的应用评价
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作者 杨默迟 魏文斌 王倩 《中华实验眼科杂志》 CAS CSCD 北大核心 2024年第8期722-728,共7页
目的评价超广角视网膜激光扫描成像(UWFSLO)在糖尿病视网膜病变(DR)筛查中的应用价值。方法采用横断面研究,选取2016年10—12月在河北省唐山市开滦康复医院行DR筛查的2型糖尿病患者1288例2304眼,收集患者一般信息,完成UWFSLO和45°... 目的评价超广角视网膜激光扫描成像(UWFSLO)在糖尿病视网膜病变(DR)筛查中的应用价值。方法采用横断面研究,选取2016年10—12月在河北省唐山市开滦康复医院行DR筛查的2型糖尿病患者1288例2304眼,收集患者一般信息,完成UWFSLO和45°水平两视野数字彩色眼底照相检查,比较DR的检出及分级水平。不同眼底检查对DR分级的一致性采用Cohen Kappa检验。结果去除成像不清晰及缺失的图像,最终1857眼纳入分析。彩色眼底照相、UWFSLO复合彩色图像及绿通道图像对DR的检出率分别为31.3%(581/1857)、44.5%(826/1857)和43.4%(807/1857),差异有统计学意义(χ^(2)=85.547,P<0.001),其中UWFSLO复合彩色图像、绿通道图像对DR的检出率均高于彩色眼底照相,差异均有统计学意义(均P<0.001)。45°水平两视野数字彩色眼底照相与UWFSLO复合彩色图像在DR检出分级之间的一致性一般,Kappa值为0.375(P<0.001),完全一致性为64.08%。UWFSLO绿通道图像与复合彩色图像对DR分级的一致性极好,Kappa值为0.953(P=0.008),完全一致性为98.17%。UWFSLO复合彩色图像对微动脉瘤(MA)、视网膜内微血管异常(IRMA)、视网膜新生血管(NV)病变的检出水平均低于绿通道图像,差异均有统计学意义(Z=-16.489、-4.198、-2.111,均P<0.05)。结论UWFSLO较45°水平两视野数字彩色眼底照相对DR的检出及分级评估水平更高,其中绿通道图像在MA、IRMA和小的NV病变检出上更为出色。在大规模人群DR的筛查及诊断中,UWFSLO具有较好的应用价值。 展开更多
关键词 糖尿病 糖尿病视网膜病变 大规模筛查 超广角视网膜激光扫描成像 两视野数字彩色眼底照相
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