Deconvolution is a commonly employed technique for enhancing image quality in optical imaging methods.Unfortu-nately,its application in optical coherence tomography(OCT)is often hindered by sensitivity to noise,which ...Deconvolution is a commonly employed technique for enhancing image quality in optical imaging methods.Unfortu-nately,its application in optical coherence tomography(OCT)is often hindered by sensitivity to noise,which leads to ad-ditive ringing artifacts.These artifacts considerably degrade the quality of deconvolved images,thereby limiting its effect-iveness in OCT imaging.In this study,we propose a framework that integrates numerical random phase masks into the deconvolution process,effectively eliminating these artifacts and enhancing image clarity.The optimized joint operation of an iterative Richardson-Lucy deconvolution and numerical synthesis of random phase masks(RPM),termed as De-conv-RPM,enables a 2.5-fold reduction in full width at half-maximum(FWHM).We demonstrate that the Deconv-RPM method significantly enhances image clarity,allowing for the discernment of previously unresolved cellular-level details in nonkeratinized epithelial cells ex vivo and moving blood cells in vivo.展开更多
Multi-channel detection is an effective way to improve data throughput of spectral-domain optical coherence tomography(SDOCT).However,current multi-channel OCT requires multiple detectors,which increases the complexit...Multi-channel detection is an effective way to improve data throughput of spectral-domain optical coherence tomography(SDOCT).However,current multi-channel OCT requires multiple detectors,which increases the complexity and cost of the system.We propose a novel multi-channel detection design based on a single spectrometer.Each camera pixel receives interferometric spectral signals from all the channels but with a spectral shift between two channels.This design effectively broadens the spectral bandwidth of each pixel,which reduces relative intensity noise(RIN)by√M times with M being the number of channels.We theoretically analyzed the noise of the proposed design under two cases:shot-noise limited and electrical noise or RIN limited.We show both theoretically and experimentally that this design can effectively improve the sensitivity,especially for electrical noise or RIN-dominated systems.展开更多
目的通过列线图的形式构建预测模型以评估前列腺癌根治术后病理较术前穿刺病理升级的风险。方法收集了2015年1月至2020年6月期间接受前列腺癌根治性切除术患者共158例的临床资料,建模集研究对象年龄跨度46岁~81岁,通过列线图的形式构建...目的通过列线图的形式构建预测模型以评估前列腺癌根治术后病理较术前穿刺病理升级的风险。方法收集了2015年1月至2020年6月期间接受前列腺癌根治性切除术患者共158例的临床资料,建模集研究对象年龄跨度46岁~81岁,通过列线图的形式构建预测模型。结果我们构建的预测模型包含了前列腺特异性抗原密度(prostatespecific antigen density,PSAD)、第2版前列腺影像报告和数据系统评分(Prostate Imaging-Reporting and Data System score version 2.0,PI-RADS评分V2.0)、前列腺穿刺阳性针数占比、身体质量指数(Body Mass Index,BMI)、穿刺病理ISUP分组(International Society of Urological Pathology,ISUP)共五个变量,该模型外部验证的C指数为0.818、Calibration曲线的P值为0.562,决策曲线也显示该模型评估效果良好。结论本研究构建的预测模型有助于在前列腺癌根治术后病理升级方面进行个体化预测。展开更多
Background:To explore the relationship between corneal biomechanical parameters and corneal sublayer thickness using corneal visualization Scheimpflug technology(Corvis ST)and ultrahigh-resolution optical coherence to...Background:To explore the relationship between corneal biomechanical parameters and corneal sublayer thickness using corneal visualization Scheimpflug technology(Corvis ST)and ultrahigh-resolution optical coherence tomography(UHR-OCT)in clinical and suspected keratoconus and normal eyes.Methods:Cross-sectional prospective study.A total of 94 eyes of 70 participants were recruited.Twenty five eyes of 19 keratoconus patients,52 eyes of 34 patients showing high risk of developing keratoconus according to the Belin/Ambrosio Enhanced Ectasia Display,and each eye of 17 normal subjects were enrolled.All participants underwent Corvis ST,Pentacam,and UHR-OCT examinations at the same time.Stiffness parameter A1(SP-A1),deformation amplitude ratio(DA ratio),and other biomechanical parameters were recorded using Corvis ST.The vertical and horizontal thickness profiles of central 3mm corneal epithelium,Bowman’s layer,and stroma as measured by the perpendicular distance between the neighboring interfaces were generated using UHR-OCT.The flat keratometry and steep keratometry were obtained using Pentacam.Analysis of correlation was applied to explore the association between variables.Results:Most of the biomechanical parameters and corneal sublayer thickness profiles showed statistical differences among three groups.A statistically significant linear relationship was noted between SP-A1 and DA ratio in all three groups.SP-A1 was found to be positively correlated with epithelial and Bowman’s layer thickness in the keratoconus(KC)group,and with stromal thickness in all three groups.In the normal and suspected keratoconus(SKC)groups,only stromal thickness was included in the stepwise linear regression to predict SP-A1,whereas in the KC group,steep keratometry and Bowman’s layer thickness were included.Conclusions:Significant and different correlations were noted between corneal stiffness and corneal sublayer thickness in different groups,indicating that corneal sublayers may play different roles in maintaining corneal biomechanical stability between keratoconus and normal eyes.展开更多
基金supported by the Guangdong Natural Science Fund General Program (2023A1515011289)Singapore Ministry of Health's National Medical Research Council under its Open Fund Individual Research Grant (MOH-OFIRG19may-0009)+2 种基金Ministry of Education Singapore under its Academic Research Fund Tier 1 (RG35/22)Academic Research Funding Tier 2 (MOE-T2EP30120-0001)China-Singapore International Joint Research Institute (203-A022001).
文摘Deconvolution is a commonly employed technique for enhancing image quality in optical imaging methods.Unfortu-nately,its application in optical coherence tomography(OCT)is often hindered by sensitivity to noise,which leads to ad-ditive ringing artifacts.These artifacts considerably degrade the quality of deconvolved images,thereby limiting its effect-iveness in OCT imaging.In this study,we propose a framework that integrates numerical random phase masks into the deconvolution process,effectively eliminating these artifacts and enhancing image clarity.The optimized joint operation of an iterative Richardson-Lucy deconvolution and numerical synthesis of random phase masks(RPM),termed as De-conv-RPM,enables a 2.5-fold reduction in full width at half-maximum(FWHM).We demonstrate that the Deconv-RPM method significantly enhances image clarity,allowing for the discernment of previously unresolved cellular-level details in nonkeratinized epithelial cells ex vivo and moving blood cells in vivo.
基金supported by the Singapore Ministry of Health’s National Medical Research Council under its Open Fund Individual Research Grant(No.MOH-000384)the Singapore Ministry of Education under its Academic Research Funding Tier 2(No.MOE-T2EP30120-0001)+1 种基金the Academic Research Funding Tier 1(No.RG35/22)the China Scholarship Council,and the National Natural Science Foundation of China(NSFC)(No.12004381)。
文摘Multi-channel detection is an effective way to improve data throughput of spectral-domain optical coherence tomography(SDOCT).However,current multi-channel OCT requires multiple detectors,which increases the complexity and cost of the system.We propose a novel multi-channel detection design based on a single spectrometer.Each camera pixel receives interferometric spectral signals from all the channels but with a spectral shift between two channels.This design effectively broadens the spectral bandwidth of each pixel,which reduces relative intensity noise(RIN)by√M times with M being the number of channels.We theoretically analyzed the noise of the proposed design under two cases:shot-noise limited and electrical noise or RIN limited.We show both theoretically and experimentally that this design can effectively improve the sensitivity,especially for electrical noise or RIN-dominated systems.
文摘目的通过列线图的形式构建预测模型以评估前列腺癌根治术后病理较术前穿刺病理升级的风险。方法收集了2015年1月至2020年6月期间接受前列腺癌根治性切除术患者共158例的临床资料,建模集研究对象年龄跨度46岁~81岁,通过列线图的形式构建预测模型。结果我们构建的预测模型包含了前列腺特异性抗原密度(prostatespecific antigen density,PSAD)、第2版前列腺影像报告和数据系统评分(Prostate Imaging-Reporting and Data System score version 2.0,PI-RADS评分V2.0)、前列腺穿刺阳性针数占比、身体质量指数(Body Mass Index,BMI)、穿刺病理ISUP分组(International Society of Urological Pathology,ISUP)共五个变量,该模型外部验证的C指数为0.818、Calibration曲线的P值为0.562,决策曲线也显示该模型评估效果良好。结论本研究构建的预测模型有助于在前列腺癌根治术后病理升级方面进行个体化预测。
基金supported by Zhejiang Provincial Natural Science Foundation of China under Grant No.LY17H120005Key Projects in Scientific Research Foundation of National Health Commission and Medical Science and Technology Program of Zhejiang Province,WKJ-ZJ-1930Wenzhou Science and Technology Project of Social Development in Medicine and Health,ZY2020010.
文摘Background:To explore the relationship between corneal biomechanical parameters and corneal sublayer thickness using corneal visualization Scheimpflug technology(Corvis ST)and ultrahigh-resolution optical coherence tomography(UHR-OCT)in clinical and suspected keratoconus and normal eyes.Methods:Cross-sectional prospective study.A total of 94 eyes of 70 participants were recruited.Twenty five eyes of 19 keratoconus patients,52 eyes of 34 patients showing high risk of developing keratoconus according to the Belin/Ambrosio Enhanced Ectasia Display,and each eye of 17 normal subjects were enrolled.All participants underwent Corvis ST,Pentacam,and UHR-OCT examinations at the same time.Stiffness parameter A1(SP-A1),deformation amplitude ratio(DA ratio),and other biomechanical parameters were recorded using Corvis ST.The vertical and horizontal thickness profiles of central 3mm corneal epithelium,Bowman’s layer,and stroma as measured by the perpendicular distance between the neighboring interfaces were generated using UHR-OCT.The flat keratometry and steep keratometry were obtained using Pentacam.Analysis of correlation was applied to explore the association between variables.Results:Most of the biomechanical parameters and corneal sublayer thickness profiles showed statistical differences among three groups.A statistically significant linear relationship was noted between SP-A1 and DA ratio in all three groups.SP-A1 was found to be positively correlated with epithelial and Bowman’s layer thickness in the keratoconus(KC)group,and with stromal thickness in all three groups.In the normal and suspected keratoconus(SKC)groups,only stromal thickness was included in the stepwise linear regression to predict SP-A1,whereas in the KC group,steep keratometry and Bowman’s layer thickness were included.Conclusions:Significant and different correlations were noted between corneal stiffness and corneal sublayer thickness in different groups,indicating that corneal sublayers may play different roles in maintaining corneal biomechanical stability between keratoconus and normal eyes.
