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Repeatability and Reproducibility of Quantitative Assessment of the Retinal Microvasculature Using Optical Coherence Tomography Angiography Based on Optical Microangiography 被引量:8
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作者 ZHAO Qi yang wen li +12 位作者 WANG Xiao Na Ruikang K Wang YOU Qi Sheng CHU Zhong Di XIN Chen ZHANG Meng Yu li Dong Jun WANG Zi yang CHEN Wei li Yi Feng CUI Rui SHEN lin WEI wen Bin 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2018年第6期407-412,共6页
Objective The aim of this study was to determine the repeatability and reproducibility of optical coherence tomography angiography(OCTA) based on optical microangiography(OMAG) measurements of macular vessels in n... Objective The aim of this study was to determine the repeatability and reproducibility of optical coherence tomography angiography(OCTA) based on optical microangiography(OMAG) measurements of macular vessels in normal eyes. Methods In this prospective cohort study, 40 eyes of 40 healthy volunteers underwent repeated OCTA(Cirrus HD-OCT 5000 angiography system, Carl Zeiss Meditec, Inc.) scans on two separate visit days. On each visit day, the eyes were scanned three times. The following parameters were used to quantitatively describe the OCTA images of the superficial vascular network: vessel area density(VAD), vessel skeleton density(VSD), vessel diameter index(VDI), vessel perimeter index(VPI), vessel complexity index(VCI), flux, and foveal avascular zone(FAZ). Coefficient of variation(CV) and intraclass correlation coefficient(ICC) were calculated for evaluating intravisit and intervisit repeatability, as well as interobserver reproducibility. Results The measurements showed high repeatability [CVs ≤ 4.2%(intravisit) and ≤ 4.6%(intervisit)] and interobserver reproducibility(ICCs ≥ 0.923) for all parameters. Conclusion This study demonstrated good repeatability and reproducibility of OCTA based on OMAG for the measurement of superficial vessel parameters in normal eyes. 展开更多
关键词 Optical coherence tomography angiography REPEATABILITY REPRODUCIBILITY Macular bloodflow Retinal superficial capillary Vascular quantification
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Automated Classification of Inherited Retinal Diseases in Optical Coherence Tomography Images Using Few-shot Learning
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作者 ZHAO Qi MAI Si Wei +7 位作者 li Qian HUANG Guan Chong GAO Ming Chen yang wen li WANG Ge MA Ya li Lei PENG Xiao Yan 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2023年第5期431-440,共10页
Objective To develop a few-shot learning(FSL) approach for classifying optical coherence tomography(OCT) images in patients with inherited retinal disorders(IRDs).Methods In this study, an FSL model based on a student... Objective To develop a few-shot learning(FSL) approach for classifying optical coherence tomography(OCT) images in patients with inherited retinal disorders(IRDs).Methods In this study, an FSL model based on a student–teacher learning framework was designed to classify images. 2,317 images from 189 participants were included. Of these, 1,126 images revealed IRDs, 533 were normal samples, and 658 were control samples.Results The FSL model achieved a total accuracy of 0.974–0.983, total sensitivity of 0.934–0.957, total specificity of 0.984–0.990, and total F1 score of 0.935–0.957, which were superior to the total accuracy of the baseline model of 0.943–0.954, total sensitivity of 0.866–0.886, total specificity of 0.962–0.971,and total F1 score of 0.859–0.885. The performance of most subclassifications also exhibited advantages. Moreover, the FSL model had a higher area under curves(AUC) of the receiver operating characteristic(ROC) curves in most subclassifications.Conclusion This study demonstrates the effective use of the FSL model for the classification of OCT images from patients with IRDs, normal, and control participants with a smaller volume of data. The general principle and similar network architectures can also be applied to other retinal diseases with a low prevalence. 展开更多
关键词 Few-shot learning Student-teacher learning Knowledge distillation Transfer learning Optical coherence tomography Retinal degeneration Inherited retinal diseases
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安徽巢湖凤凰山晚古生代大冰期沉积特征与碳同位素变化 被引量:1
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作者 杨文莉 仲钰天 +4 位作者 辛浩 郑全锋 祁玉平 王玥 陈吉涛 《地层学杂志》 CSCD 北大核心 2021年第1期38-48,共11页
地史中海相碳酸盐岩记录的无机碳同位素的波动经常与全球气候事件相互关联,但碳酸盐岩的碳同位素不仅与全球碳循环相关,也受控于区域水循环和成岩作用。晚古生代大冰期在石炭纪末—早二叠世达到最高峰,南方冈瓦纳大陆高纬度地区冰川的... 地史中海相碳酸盐岩记录的无机碳同位素的波动经常与全球气候事件相互关联,但碳酸盐岩的碳同位素不仅与全球碳循环相关,也受控于区域水循环和成岩作用。晚古生代大冰期在石炭纪末—早二叠世达到最高峰,南方冈瓦纳大陆高纬度地区冰川的进退引起低纬度地区旋回性的海平面变化,并发育显著的沉积间断,在华南表现为喀斯特岩溶角砾岩等。本文选取安徽巢湖凤凰山剖面,对宾夕法尼亚亚系—乌拉尔统18m厚的碳酸盐岩地层(黄龙组和船山组)进行了详细的沉积学与碳同位素对比研究,以探索碳同位素变化的控制因素。本文共识别出厚层灰泥灰岩、厚层粒泥灰岩、中至厚层泥粒灰岩、厚层泥球颗粒灰岩、薄层鲕粒颗粒灰岩、厚至巨厚层生物碎屑颗粒灰岩、厚层核形石颗粒灰岩、薄至中层灰砾岩和炉渣状灰岩等9种沉积岩相,指示了多次暴露的碳酸盐台地环境。这些暴露特征与同时期贵州罗甸斜坡相碳酸盐岩序列(约194 m)对比,表明凤凰山剖面存在严重的地层缺失。揭示了研究层段11 m和14 m附近的碳同位素两次显著负漂(幅度约为6‰和7‰)与古喀斯特层对应,是由碳酸盐台地暴露引起的区域成岩改造导致的,而非源于引起气候变化的全球碳循环波动。因此,地层学、沉积学和地球化学等多学科综合交叉研究是深入揭示古气候和古海洋变化规律的重要前提。 展开更多
关键词 沉积相 碳同位素 晚古生代大冰期 石炭系 二叠系 古喀斯特
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