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Repeatability,interocular correlation and agreement of optic nerve head vessel density in healthy eyes:a sweptsource optical coherence tomographic angiography study
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作者 Dan-Qi Fang Da-Wei Yang +2 位作者 Xiao-Ting Mai Carol Y Cheung Hao-Yu Chen 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第5期896-903,共8页
AIM:To assess the repeatability,interocular correlation,and agreement of quantitative swept-source optical coherence tomography angiography(OCTA)optic nerve head(ONH)parameters in healthy subjects.METHODS:Thir ty-thre... AIM:To assess the repeatability,interocular correlation,and agreement of quantitative swept-source optical coherence tomography angiography(OCTA)optic nerve head(ONH)parameters in healthy subjects.METHODS:Thir ty-three healthy subjects were enrolled.The ONH of both eyes were imaged four times by a swept-source-OCTA using a 3 mm×3 mm scanning protocol.Images of the radial peripapillary capillary were analyzed by a customized Matlab program,and the vessel density,fractal dimension,and vessel diameter index were measured.The repeatability of the four scans was determined by the intraclass correlation coefficient(ICC).The most well-centered optic disc from the four repeated scans was then selected for the interocular correlation and agreement analysis using the Pearson correlation coefficient,ICC and Bland-Altman plots.RESULTS:All swept-source-OCTA ONH parameters exhibited certain repeatability,with ICC>0.760 and coefficient of variation(CoV)≤7.301%.The obvious interocular correlation was observed for papillary vessel density(ICC=0.857),vessel diameter index(ICC=0.857)and fractal dimension(ICC=0.906),while circumpapillary vessel density exhibited moderate interocular correlation(ICC=0.687).Bland-Altman plots revealed an agreement range of-5.26%to 6.21%for circumpapillary vessel density.CONCLUSION:OCTA ONH parameters demonstrate good repeatability in healthy subjects.The interocular correlations of papillary vessel density,fractal dimension and vessel diameter index are high,but the correlation for circumpapillary vessel density is moderate. 展开更多
关键词 interocular correlation REPEATABILITY optic nerve head optical coherence tomography angiography vessel density
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Quantifying peripapillary vessel density and retinal nerve fibre layer in type 1 diabetic children without clinically detectable retinopathy using OCTA
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作者 Ling Chen Yun Feng +2 位作者 Sha-Sha Zhang Yan-Fang Liu Ping Lin 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第2期278-281,共4页
AIM:To quantify changes in radial peripapillary capillary vessel density(ppVD)and the peripapillary retinal nerve fiber layer(pRNFL)in children with type 1 diabetes without clinical diabetic retinopathy by optical coh... AIM:To quantify changes in radial peripapillary capillary vessel density(ppVD)and the peripapillary retinal nerve fiber layer(pRNFL)in children with type 1 diabetes without clinical diabetic retinopathy by optical coherence tomography angiography(OCTA),providing a basis for early retinopathy in children with type 1 diabetes.METHODS:This was a retrospective study.A total of 30 patients(3–14y)with type 1 diabetes without clinical diabetic retinopathy(NDR group)were included.A total of 30 age-matched healthy subjects were included as the normal control group(CON group).The HbA1c level in the last 3mo was measured once in the NDR group.The pRNFL thickness and ppVD were automatically measured,and the mean pRNFL and ppVD were calculated in the nasal,inferior,temporal,and superior quadrants.The changes in ppVD and pRNFL in the two groups were analyzed.RESULTS:Compared with CON group,the nasal and superior ppVDs decreased in the NDR group(all P<0.01).The thickness of the nasal pRNFL decreased significantly(P<0.01),while the inferior,temporal and superior pRNFLs slightly decreased but not significant in the NDR group(all P>0.05).Person and Spearman correlation analysis of ppVD and pRNFL thickness in each quadrant of the NDR group showed a positive correlation between nasal and superior(all P<0.01),while inferior and temporal had no significant correlation(all P>0.05).There was no significant correlation between the HbA1c level and ppVD and pRNFL in any quadrant(all P>0.05).There was no significant correlation between the course of diabetes mellitus and ppVD and pRNFL in any quadrant(all P>0.05).CONCLUSION:ppVD and pRNFL decrease in eyes of children with type 1 diabetes before clinically detectable retinopathy and OCTA is helpful for early monitoring. 展开更多
关键词 diabetic retinopathy CHILDREN peripapillary vessel density peripapillary retinal nerve fiber layer optical coherence tomography angiography
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Structural measurements and vessel density of spectraldomain optic coherence tomography in early,moderate,and severe primary angle-closure glaucoma 被引量:2
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作者 Wei Jiang Nan Jiang +3 位作者 Gui-Bo Liu Jing Lin Cui Li Gui-Qiu Zhao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第7期1100-1109,共10页
AIM:To compare the macular ganglion cell-inner plexiform layer(GCIPL)thickness,retinal nerve fiber layer(RNFL)thickness,optic nerve head(ONH)parameters,and retinal vessel density(VD)measured by spectral-domain optical... AIM:To compare the macular ganglion cell-inner plexiform layer(GCIPL)thickness,retinal nerve fiber layer(RNFL)thickness,optic nerve head(ONH)parameters,and retinal vessel density(VD)measured by spectral-domain optical coherence tomography(SD-OCT)and analyze the correlations between them in the early,moderate,severe primary angle-closure glaucoma(PACG)and normal eyes.METHODS:Totally 70 PACG eyes and 20 normal eyes were recruited for this retrospective analysis.PACG eyes were further separated into early,moderate,or severe PACG eyes using the Enhanced Glaucoma Staging System(GSS2).The GCIPL thickness,RNFL thickness,ONH parameters,and retinal VD were measured by SD-OCT,differences among the groups and correlations within the same group were calculated.RESULTS:The inferior and superotemporal sectors of the GCIPL thickness,rim area of ONH,average and inferior sector of the retinal VD were significantly reduced(all P<0.05)in the early PACG eyes compared to the normal and the optic disc area,cup to disc ratio(C/D),and cup volume were significantly higher(all P<0.05);but the RNFL was not significant changes in early and moderate PACG.In severe group,the GCIPL and RNFL thickness were obvious thinning with retinal VD were decreasing as well as C/D and cup volume increasing than other three groups(all P<0.01).In the early PACG subgroup,there were significant positive correlations between retinal VD and GCIPL thickness(except superonasal and inferonasal sectors,r=0.573 to 0.641,all P<0.05),superior sectors of RNFL thickness(r=0.055,P=0.049).More obvious significant positive correlations were existed in moderate PACG eyes between retinal VD and superior sectors of RNFL thickness(r=0.650,P=0.022),and temporal sectors of RNFL thickness(r=0.740,P=0.006).In the severe PACG eyes,neither GCIPL nor RNFL thickness was associated with retinal VD.CONCLUSION:The ONH damage and retinal VD loss appears earlier than RNFL thickness loss in PACG eyes.As the PACG disease progressed from the early to the moderate stage,the correlations between the retinal VD and RNFL thickness increases. 展开更多
关键词 optic coherence tomography primary angle-closure glaucoma ganglion cell-inner plexiform layer retinal nerve fiber layer optic nerve head retinal vessel density
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Evaluation of optic nerve head vessels density changes after phacoemulsification cataract surgery using optical coherence tomography angiography 被引量:1
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作者 Ze-Hui Zhu Yin-Ying Zhao +4 位作者 Rui Zou Han Zou Jia-Yan Fang Ping-Jun Chang Yun-E Zhao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第6期884-890,共7页
·AIM:To evaluate optic nerve head(ONH)vessel density(VD)changes after cataract surgery using optical coherence tomography angiography(OCTA).·METHODS:This was a prospective observational study.Thirty-four eye... ·AIM:To evaluate optic nerve head(ONH)vessel density(VD)changes after cataract surgery using optical coherence tomography angiography(OCTA).·METHODS:This was a prospective observational study.Thirty-four eyes with mild/moderate cataracts were included.ONH scans were obtained before and 3mo after cataract surgery using OCTA.Radial peripapillary capillary(RPC)density,all VD,large VD and retinal nerve fiber layer thickness(RNFLT)in total disc,inside disc,and different peripapillary sectors were assessed and analyzed.Image quality score(QS),fundus photography grading and bestcorrected visual acuity(BCVA)were also collected,and correlation analyses were performed between VD change and these parameters.·RESULTS:Compared with baseline,both RPC and all VD increased in inside disc area 3mo postoperatively(from 47.5%±5.3%to 50.2%±3.7%,and from 57.87%±4.30%to 60.47%±3.10%,all P<0.001),but no differences were observed in peripapillary area.However,large VD increased from 5.63%±0.77%to 6.47%±0.72%in peripapillary ONH region(P<0.001).RPC decreased in inferior and superior peripapillary ONH parts(P=0.019,<0.001 respectively).There were obvious negative correlations between RPC change and large VD change in inside disc,superior-hemi,and inferior-hemi(r=-0.419,-0.370,and-0.439,P=0.017,0.044,and 0.015,respectively).No correlations were found between VD change and other parameters including QS change,fundus photography grading,postoperative BCVA,and postoperative peripapillary RNFLT.·CONCLUSION:RPC density and all VD in the inside disc ONH region increase 3mo after surgery in patients with mild to moderate cataract.No obvious VD changes are found in peripapillary area postoperatively. 展开更多
关键词 PHACOEMULSIFICATION CATARACT optical coherence tomography angiography vessel density optic nerve head
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Microvessel density is a prognostic marker of human gastric cancer 被引量:25
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作者 Hong-Chuan Zhao Rong Qin +4 位作者 Xiao-Xin Chen Xia Sheng Ji-Feng Wu Dao-Bin Wang Gui-Hua Chen 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第47期7598-7603,共6页
AIM: To investigate whether microvessel density (MVD) is related with prognosis in gastric cancer patients, and the expression of cyclooxygenase-2 (COX-2) and vessel endothelial growth factor (VEGF) so as to determine... AIM: To investigate whether microvessel density (MVD) is related with prognosis in gastric cancer patients, and the expression of cyclooxygenase-2 (COX-2) and vessel endothelial growth factor (VEGF) so as to determine the possible role of COX-2 and VEGF in gastric cancer angiogenesis.METHODS: Forty-seven formalin-fixed paraffin-embedded tissue samples of gastric cancer were evaluated for COX-2, VEGF by immunohitochemical staining. To assess tumor angiogenesis, MVD was determined by immunohitochemical staining of endothelial protein factor Ⅷ-related antigen. The relationship among COX-2 and VEGF expression, MVD, and clinicopathologic parameters was analyzed. RESULTS: Among the 67 samples, high MVD was significantly associated with lymph node metastasis and poor survival. Multivariate survival analysis showed that MVD value and lymph node metastasis were independent prognostic factors. The expression rate of COX-2 and VEGF was significantly higher than that of the adjacent tissues. COX-2 and VEGF expression in gastric cancer was significantly correlated with tumor differentiation and depth of invasion, but not with survival. The mean MVD value of COX-2 or VEGF positive tumors was higher than that of COX-2 or VEGF negative tumors. A significant correlation was found between the expressions of COX-2and VEGF. CONCLUSION: MVD may be one of the important prognostic factors for gastric cancer patients. COX-2 and VEGF may play an important role in tumor progression by stimulating angiogenesis. VEGF might play a main role in the COX-2 angiogenic pathway. The inhibition of angiogenesis or COX-2, VEGF activity may have an important therapeutic benefit in the control of gastric cancer. 展开更多
关键词 Gastric cancer ANGIOGENESIS Microvessel density vessel endothelial growth factor CYCLOOXYGENASE Prognostic marker Nonsteroidal anti inflammatory drug
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Peripapillary vessel density and retinal nerve fiber layer thickness changes in early diabetes retinopathy 被引量:2
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作者 Xiang-Ning Wang Xuan Cai +2 位作者 Ting-Ting Li Da Long Qiang Wu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2022年第9期1488-1495,共8页
·AIM:To perform a quantitative analysis of the peripapillary vessel density(VD)and retinal nerve fiber layer(RNFL)thickness changes in patients with early stage of diabetic retinopathy(DR).·METHODS:In this c... ·AIM:To perform a quantitative analysis of the peripapillary vessel density(VD)and retinal nerve fiber layer(RNFL)thickness changes in patients with early stage of diabetic retinopathy(DR).·METHODS:In this case-control study,swept-source optical coherence tomography angiography(SS-OCTA)imaging was used to examine diabetic and age-matched healthy subjects.The optic disc HD 6×6 mm^(2) blood flow imaging scan mode was selected.Automatic software was used to measure the peripapillary VD,capillary vessel density(CVD),and RNLF in an optic nerve head(ONH)filed based on the Garway-Heath map.In addition,the correlation between peripapillary VD,CVD,and RNFL was further investigated.·RESULTS:The cohort consisted of 32 healthy individuals and 72 patients with diabetes(34 eyes with no DR and 38 eyes with mild-moderate NPDR).Peripapillary VD decreased in the mild-moderate NPDR group compared to the control group in most regions(P<0.05).Peripapillary CVD and RNFL thickness were significantly lower in the mild-moderate NPDR group in the superior temporal(ST)quadrants(P=0.018.P=0.030).In the correlation analysis of each region,the RNFL thickness in the NS region was positively correlated with the peripapillary VD and CVD(r=0.233,P=0.05;r=0.288.P=0.015).In the TI region,the RNFL thickness was positively correlated with the peripapillary CVD(r=0.237,P=0.047).·CONCLUSION:The measurement based on the ONH topographic map may be helpful in detecting functional and structural impairments in DR.The peripapillary VD,CVD and RNFL decrease in early DR,and the RNFL thickness altered in association with the CVD or/and VD in some regions. 展开更多
关键词 vessel density retinal nerve fiber layer diabetic retinopathy OCTA swept-source
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Evaluation of macular vessel density changes after vitrectomy with silicone oil tamponade in patients with rhegmatogenous retinal detachment 被引量:1
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作者 Jian Jiang Song Chen +3 位作者 Ya-Ding Jia Rui Li Jin-Xiu Zhou Rui-Mei Li 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2021年第6期881-886,共6页
AIM:To evaluate macular microvasculature changes in eyes after pars plana vitrectomy(PPV)and intraocular silicone oil(SO)tamponade for macula-off rhegmatogenous retinal detachment(RRD)using optical coherence tomograph... AIM:To evaluate macular microvasculature changes in eyes after pars plana vitrectomy(PPV)and intraocular silicone oil(SO)tamponade for macula-off rhegmatogenous retinal detachment(RRD)using optical coherence tomography angiography(OCTA).METHODS:Totally 19 eyes(19 patients)with maculaoff RRD who underwent PPV and intraocular SO tamponade were retrospectively reviewed.The parafoveal superficial capillary plexus(SCP)vessel density(VD),deep capillary plexus(DCP)VD,choriocapillaris plexus(CCP)VD,and foveal macular thickness were evaluated using OCTA throughout 16 wk postoperatively.The values of healthy fellow eyes were used as control.RESULTS:The parafoveal SCP,DCP,and CCP VDs were significant increased over time in RRD eyes during the 12 wk postoperatively,then decreased at 16 wk postoperatively(all P<0.01).The ratios of RRD eyes and fellow healthy eyes(r/f ratios)of the SCP and DCP VDs were lower than those of the CCP VD postoperatively(all P<0.05).There were not significant differences in the r/f ratios between SCP and DCP VDs postoperatively(all P>0.05).CONCLUSION:The parafoveal SCP,DCP,and CCP VDs gradually recover over time after PPV surgery with SO tamponade.Long-time SO tamponade might decrease postoperative macular VDs.Compared to parafoveal CCP VD,the parafoveal SCP and DCP VDs were more vulnerable in RRD eyes postoperatively. 展开更多
关键词 rhegmatogenous retinal detachment vessel density silicone oil VITRECTOMY optical coherence tomography angiography
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A Study on Improvement of RANS Analysis for Erosion of Density Stratified Layer of Multicomponent Gas by Buoyant Jet in a Containment Vessel
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作者 Satoshi Abe Masahiro Ishigaki Yasuteru Sibamoto Taisuke Yonomoto 《Journal of Energy and Power Engineering》 2015年第7期599-607,共9页
The analysis on a density stratification layer consisting of multiple gases in the reactor containment vessel is important for the safety assessment of sever accidents. The JAEA (Japan Atomic Energy Agency) has star... The analysis on a density stratification layer consisting of multiple gases in the reactor containment vessel is important for the safety assessment of sever accidents. The JAEA (Japan Atomic Energy Agency) has started the project on the containment thermal hydraulics. We carried out CFD (computational fluid dynamics) analyses in order to investigate the erosion of the density stratification layer by a vertical buoyant jet under this project. We used the RANS (Reynolds averaged numerical simulation) and LES (large eddy simulation) models to analyze the erosion of a density stratification layer by a vertical buoyant jet in a small vessel which represents a containment vessel. This numerical study calculates the turbulent mixing of a two-component (air and helium) gas mixture. The turbulence models used for the RANS analyses are two types of k-ε models. The first model is the low Reynolds number k-ε model developed by Launder and Sharma. The second model is modified from the first model in order to accurately consider the turbulent production and damping in a stratification layer. The results indicated while the erosion rate calculated by the low-Re k-ε model was much faster than that of the LES model, the modified k-ε model could calculate the erosion rate similar to the LES result. 展开更多
关键词 density stratification layer containment vessel CFD Kato-Launder modification Katsuki model
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Correlation between macular blood flow density and stage of diabetic retinopathy
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作者 DENG Yu JIE Chuan-hong +3 位作者 WANG Jian-wei SONG Xiao-hua LIU Zi-qiang LI Yuan-yuan 《Journal of Hainan Medical University》 2023年第3期36-41,共6页
Objective:To investigate the association between the development of diabetic retinopathy and OCTA blood flow density.Methods:A total of 63 patients(100 eyes)diagnosed with type 2 diabetes in Eye Hospital of China Acad... Objective:To investigate the association between the development of diabetic retinopathy and OCTA blood flow density.Methods:A total of 63 patients(100 eyes)diagnosed with type 2 diabetes in Eye Hospital of China Academy of Chinese Medical Sciences from September 2020 to July 2021 were selected,including 44 patients(72 eyes)with diabetic retinopathy and 19 patients(28 eyes)with type 2 diabetes without retinopathy(NDR).All patients underwent OCTA examination,and FAZ,PERIM,AI,FD,SVD,DVD and other indicators were counted.Results:(1)SVD,parafoveal SVD,DVD and parafoveal DVD gradually decreased with the progression of DR(P=0.000).There was no significant difference in SVD and DVD fovea(P>0.05).(2)The correlation coefficients between SVD,SVD,DVD,DVD and DR process were-0.525,-0.586,-0.323,-0.424,respectively(P<0.05),and all showed moderate negative correlation.(3)AI and FD gradually decreased with the progression of DR,and the differences were statistically significant(P=0.011,P=0.000),while FAZ and PERIM showed no significant difference with the progression of DR(P>0.05).(4)The correlation coefficients of FAZ,PERIM and DR progression were:-0.031,0.084(P>0.05),no correlation,AI,FD and DR process correlation coefficient were 0.307,-0.459(P<0.05),respectively,were moderately positive and negative correlation;(5)The correlation coefficients of FAZ,PERIM,AI,FD and age were-0.124,-0.052,0.113,-0.170(P>0.05),respectively.Conclusion:There is a moderate correlation between the progression of DR and the superficial and deep blood flow density of OCTA.It was moderately correlated with AI and FD.OCTA can assist in the assessment of DR disease progression. 展开更多
关键词 Diabetic retinopathy Optical coherence tomography ANGIOGRAPHY vessel density Correlation analysis preface
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脑小血管病认知障碍患者脑电功率谱变化与中性粒细胞/淋巴细胞比值相关性及临床价值研究
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作者 郭晓敏 魏爱芹 +2 位作者 刘宗伟 袁维帅 朱娜 《陕西医学杂志》 CAS 2024年第3期361-367,共7页
目的:探索脑小血管病认知障碍(CSVCI)患者脑电功率谱变化与中性粒细胞/淋巴细胞比值(NLR)的相关性,并分析其临床价值。方法:收集脑小血管病(CSVD)患者61例,依据蒙特利尔认知评估量表(MoCA)评分,将其分为伴有认知障碍组(CSVCI组,29例)及... 目的:探索脑小血管病认知障碍(CSVCI)患者脑电功率谱变化与中性粒细胞/淋巴细胞比值(NLR)的相关性,并分析其临床价值。方法:收集脑小血管病(CSVD)患者61例,依据蒙特利尔认知评估量表(MoCA)评分,将其分为伴有认知障碍组(CSVCI组,29例)及无认知功能障碍组(CSVD组,32例),同期招募体检健康者20例为对照组(HC组)。对三组进行脑电图检查,比较全脑定量脑电图功率谱密度(PSD),并分析其与NLR的相关性。结果:CSVCI组年龄高于HC组,受教育年限低于CSVD组和HC组(均P<0.05)。CSVCI组和CSVD组高血压占比高于HC组(均P<0.05)。CSVCI组脑室旁及总脑白质Fazekas评分高于CSVD组和HC组,且CSVD组高于HC组(均P<0.05)。CSVCI组和CSVD组深部脑白质Fazekas评分高于HC组(均P<0.05)。CSVCI组δ、θ频段PSD值高于CSVD组,α频段PSD值低于CSVD组和HC组,CSVD组δ频段PSD值低于HC组(均P<0.05)。多因素Logistic回归表明α频段全脑PSD减低及受教育年限低为CSVCI发生的独立危险因素(均P<0.05)。CSVD患者α频段PSD值与MoCA评分呈正相关,δ频段PSD值与MoCA评分呈负相关,且脑室旁Fazekas评分、深部脑白质Fazekas评分及总脑白质Fazekas评分与MoCA评分呈负相关(均P<0.05)。NLR与θ频段全脑PSD呈正相关(P<0.05)。结论:CSVCI患者脑电快波活动减低而慢波活动增加。α频段全脑PSD值独立于Fazekas评分外影响CSVD患者认知障碍的发生,可能成为评估认知障碍严重程度、预测认知障碍发生的早期客观指标。NLR可能为导致脑电慢化的机制,有可能成为早期预测脑电慢化、认知障碍的客观指标。 展开更多
关键词 脑小血管病认知障碍 中性粒细胞/淋巴细胞比值 蒙特利尔认知评估量表 脑电图 功率谱密度 相关性
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光学相干断层扫描血管成像量化分析糖尿病患者黄斑区毛细血管参数 被引量:1
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作者 陆楠 杨冬妮 +6 位作者 谷愉 刘健 杨世琳 郭莹 单志明 刘丽 赵伟 《国际眼科杂志》 2024年第1期10-17,共8页
目的:应用光学相干断层扫描血管成像技术(OCTA)量化2型糖尿病患者黄斑区毛细血管的早期变化。方法:回顾性病例研究。分别纳入49名健康受试者、52例无视网膜病变的2型糖尿病患者(noDR)和43例轻度非增殖性糖尿病视网膜病变(mNPDR)患者,并... 目的:应用光学相干断层扫描血管成像技术(OCTA)量化2型糖尿病患者黄斑区毛细血管的早期变化。方法:回顾性病例研究。分别纳入49名健康受试者、52例无视网膜病变的2型糖尿病患者(noDR)和43例轻度非增殖性糖尿病视网膜病变(mNPDR)患者,并得到在黄斑区3 mm×3 mm浅层毛细血管丛和深层毛细血管丛的OCTA图像。去除大血管后分别计算毛细血管灌注密度、血管长度密度(VLD)和平均血管直径(AVD)并进行比较。应用受试者工作特征曲线评估该参数监测2型糖尿病患者视网膜微血管早期改变的能力。结果:比较三组间VLD和AVD,差异均有统计学意义(P<0.001)。与健康受试者相比,noDR组的AVD均显著增加(P<0.05)。mNPDR组患者深层及浅层的VLD较noDR组显著下降(均P<0.01)。深层AVD鉴别noDR组与健康受试者的曲线下面积(AUC)为0.796,鉴别mNPDR组和健康受试者的AUC最高为0.920,其次为深层VLD(AUC=0.899),显著高于其他参数。结论:在糖尿病视网膜病变的临床前阶段,2型糖尿病患者的深层及浅层AVD均显著高于健康人,VLD均显著高于mNPDR患者。与健康人相比,深度AVD较其他参数更能检出noDR患者早期视网膜毛细血管的变化。 展开更多
关键词 糖尿病视网膜病变 光学相干断层扫描血管成像(OCTA) 灌注密度 血管长度密度 血管直径
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低温容器用多层绝热材料的绝热性能研究进展 被引量:3
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作者 马晓勇 陈叔平 +6 位作者 金树峰 朱鸣 王洋 熊珍艳 吴慧敏 于洋 王鑫 《材料导报》 EI CSCD 北大核心 2024年第1期238-248,共11页
多层绝热材料被广泛应用于低温容器,其绝热性能是人们重点关注的性能指标。真空良好下,影响其绝热性能的因素包括夹层真空度、材料型号和种类、层数、层密度、等密度或变密度布置以及材料包覆工艺等;真空失效下,夹层气体压力、破空气体... 多层绝热材料被广泛应用于低温容器,其绝热性能是人们重点关注的性能指标。真空良好下,影响其绝热性能的因素包括夹层真空度、材料型号和种类、层数、层密度、等密度或变密度布置以及材料包覆工艺等;真空失效下,夹层气体压力、破空气体种类以及绝热结构参数等会对多层绝热材料的绝热性能产生影响。本文综述了多层绝热材料绝热性能的预测公式。应用Lockheed分析模型对不同边界温度、不同层数下的多层绝热材料的绝热性能进行预测,得到最佳层密度和最小热流密度;在层数一定的条件下,应用Layer-by-layer传热模型对等密度和变密度多层绝热方案的绝热性能进行预测,分析获得了两种实用性较高的多层绝热方案。 展开更多
关键词 多层绝热材料 绝热性能 变密度 低温容器 真空良好 真空失效
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正常眼压性青光眼患者黄斑区微循环状态与视功能改变的关系研究 被引量:1
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作者 范彩媚 臧苗苗 +4 位作者 王丽君 易澄 曾璐瑶 武天硕 李汉林 《眼科新进展》 CAS 北大核心 2024年第3期197-202,共6页
目的 联合使用光学相干断层扫描血管成像(OCTA)和微视野计探讨正常眼压性青光眼(NTG)患者黄斑区微循环状态和视功能变化情况,并分析两者之间的相关性。方法 横断面观察性研究。收集NTG患者17例30眼作为NTG组,按病情严重程度分为轻度、... 目的 联合使用光学相干断层扫描血管成像(OCTA)和微视野计探讨正常眼压性青光眼(NTG)患者黄斑区微循环状态和视功能变化情况,并分析两者之间的相关性。方法 横断面观察性研究。收集NTG患者17例30眼作为NTG组,按病情严重程度分为轻度、中度和重度NTG组3组。选取同期年龄、性别相匹配的健康体检者13例23眼作为对照组。使用OCTA获取黄斑区浅层视网膜血管线性密度(LD)及灌注密度(PD)。使用微视野计检测黄斑区10°范围的视网膜光敏感度(RS)及2°、4°固视率。比较各组间OCTA参数及微视野计参数的差异,并分析NTG患者OCTA参数与微视野计参数之间的相关性。结果 对照组与轻度NTG组受试者之间除黄斑区中央和鼻侧的LD、PD差异均无统计学意义外,其余各区域和整体平均LD、PD在对照组和轻度、中度、重度NTG组受试者间均呈逐渐下降趋势。轻度NTG组患者黄斑区下方和颞侧区域RS均较对照组受试者降低。黄斑区各区域及整体平均RS随NTG病情分期加重而降低。在NTG组患者中,LD、PD与RS在黄斑区各区域和整体平均中均呈显著性正相关(均为P<0.05)。NTG组患者黄斑区LD、PD与P2在一定区域内呈正相关。结论 NTG患者黄斑区微循环状态及视功能均较健康人显著下降,且随病情进展而加重;NTG患者黄斑区血管密度与RS存在显著相关性。 展开更多
关键词 正常眼压性青光眼 光学相干断层扫描血管成像 微视野计 血管密度 视网膜光敏感度 固视率
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分叉血管边支斑块及继生斑块发生发展趋势的动态模拟
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作者 刘昭 孙浩 +5 位作者 陶克怡 杜田明 张艳萍 刘圣文 冯继玲 乔爱科 《医用生物力学》 CAS CSCD 北大核心 2024年第5期838-845,共8页
目的考虑血管重构和低密度脂蛋白(low-density lipoproteins,LDL)沉积,探讨分叉血管边支斑块的生长发展趋势,以及因斑块存在而可能引发继生斑块的生长位置。方法建立分叉血管理想化模型,用计算流体力学方法获取边支斑块生长前后壁面切... 目的考虑血管重构和低密度脂蛋白(low-density lipoproteins,LDL)沉积,探讨分叉血管边支斑块的生长发展趋势,以及因斑块存在而可能引发继生斑块的生长位置。方法建立分叉血管理想化模型,用计算流体力学方法获取边支斑块生长前后壁面切应力分布。在低切应力区域截取7个截面:截面1~3为斑块生成前边支的低切应力区域;截面4、5为斑块上、下游边缘;截面6、7为斑块下游低切应力区域。模拟截面内血管重构和LDL沉积,讨论斑块的生长和发展趋势。结果截面1~3中,截面2产生了明显的负性重构和最高浓度LDL沉积(102.266 mmol/L),说明此处是动脉粥样硬化斑块的起始位置。当斑块产生后,相比于截面4,截面5产生了更明显的血管重构,并造成管腔的狭窄和最高的沉积浓度(110.17 mmol/L),说明斑块有向下游偏心生长的趋势。相比于截面6,截面7(血液流动分离再附着点)产生了更明显的负性重构和最高的沉积浓度(93.851 mmol/L),说明血液流动分离再附着点附近有生成新斑块的可能。结论边支低切应力处产生明显血管重构导致管腔狭窄,并引发LDL的高浓度沉积,形成动脉粥样硬化斑块。其中,分叉血管的外侧壁为动脉粥样硬化斑块生长的起始位置。在斑块生长后斑块有向下游发展的趋势,在流动分离再附着点有形成继生斑块可能。 展开更多
关键词 分叉血管 动脉粥样硬化 血管重构 低密度脂蛋白沉积 数值模拟
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大型养殖工船氧锥设计与运行效果试验
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作者 林礼群 马凤爽 +3 位作者 张耀明 徐志强 邹海生 王云杰 《渔业现代化》 CSCD 北大核心 2024年第5期48-55,共8页
保证养殖水体适宜的溶氧浓度对养殖鱼类的健康生长至关重要。为满足养殖工船超大封闭水体及高密度养殖的需氧要求,以氧锥作为研究对象,建立氧锥尺寸模型,根据双膜理论与菲克定律以及增氧机增氧能力试验标准,开展氧锥增氧性能试验。结果... 保证养殖水体适宜的溶氧浓度对养殖鱼类的健康生长至关重要。为满足养殖工船超大封闭水体及高密度养殖的需氧要求,以氧锥作为研究对象,建立氧锥尺寸模型,根据双膜理论与菲克定律以及增氧机增氧能力试验标准,开展氧锥增氧性能试验。结果显示:氧锥出口的溶氧质量浓度能达到40 mg/L,超饱溶氧接近400%,实现超高溶氧饱和度;在氧气进气量为7.6 m^(3)/h,氧锥操作压力为0.07~0.25 MPa条件下,增氧能力受操作压力影响不明显,但是最佳进气量范围受操作压力影响显著。操作压力越大,当氧气进气量增大时,越不容易形成大气泡析出水面,从而保持较高的氧气利用率;在氧气进气量大于6.5 m^(3)/h,操作压力为0.07~0.25 MPa,每个养殖舱配置1个氧锥能满足养殖舱氧量需求。该研究为大型养殖工船增氧设备的工程设计及稳定高效运行提供了基础数据。 展开更多
关键词 养殖工船 高密度养殖 氧锥 增氧能力 操作压力
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OCTA定量分析甲状腺相关性眼病和甲状腺功能亢进患者黄斑及视盘旁血管密度变化
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作者 梁从碧 周芸芸 +3 位作者 徐奕爽 蔡立维 蔡玉立 陈长征 《微循环学杂志》 2024年第2期41-47,共7页
目的:应用光学相干断层扫描血管成像(OCTA)定量分析甲状腺相关性眼病(TAO)及甲状腺功能亢进患者黄斑及视盘旁血管密度(VD)的变化,探索能够早期反映TAO发生发展的无创监测指标。方法:采用横断面临床研究。纳入2023-02-2023-06于武汉大学... 目的:应用光学相干断层扫描血管成像(OCTA)定量分析甲状腺相关性眼病(TAO)及甲状腺功能亢进患者黄斑及视盘旁血管密度(VD)的变化,探索能够早期反映TAO发生发展的无创监测指标。方法:采用横断面临床研究。纳入2023-02-2023-06于武汉大学人民医院就诊的活动期TAO患者24例(TAO组)、甲状腺功能亢进无眼部改变患者24例(甲亢组)和体检健康者24例(对照组)。三组受检者均接受黄斑HD 6mm×6mm和视盘HD 4.5mm×4.5mm扫描模式的OCTA检查,并测量浅层及深层视网膜VD、视盘旁放射状毛细血管网VD(ppVD)、视盘周围视网膜神经纤维层(RNFL)厚度及中心凹无血管区(FAZ)面积,比较三组受检眼上述指标的差异。结果:与对照组比较,TAO组和甲亢组浅层视网膜VD显著降低(P<0.05或P<0.01);与甲亢组比较,TAO组整体、N2及I2区域浅层视网膜VD显著降低(P<0.05或P<0.01)。甲亢组和TAO组中心凹区域深层视网膜VD明显低于对照组(P<0.05或P<0.01)。三组间大部分区域ppVD及RNFL厚度的差异均无统计学意义(P>0.05)。甲亢组和TAO组FAZ面积较对照组均显著扩大(P<0.05或P<0.01)。结论:甲状腺功能亢进患者在尚未发展为TAO之前已经出现浅层视网膜VD降低及FAZ面积扩大,TAO患者的相关变化较甲状腺功能亢进患者更甚,OCTA有助于早期无创监测相关指标变化。 展开更多
关键词 甲状腺功能亢进 甲状腺相关性眼病 光学相干断层扫描血管成像 血管密度
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肾功能损害及过高HDL-C对急性大血管闭塞性缺血性卒中血管内治疗患者预后的预测价值
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作者 吴晟昊 吴欢 +2 位作者 韩建 汪飞 倪初源 《皖南医学院学报》 CAS 2024年第2期149-153,共5页
目的:探讨肾功能损害(RI)及过高高密度脂蛋白胆固醇(HDL-C)对急性大血管闭塞性缺血性卒中(AIS-LVO)血管内治疗(EVT)患者预后的预测价值。方法:回顾性分析2018年7月~2022年12月黄山市人民医院神经内科接受EVT治疗的AIS-LVO患者临床资料,... 目的:探讨肾功能损害(RI)及过高高密度脂蛋白胆固醇(HDL-C)对急性大血管闭塞性缺血性卒中(AIS-LVO)血管内治疗(EVT)患者预后的预测价值。方法:回顾性分析2018年7月~2022年12月黄山市人民医院神经内科接受EVT治疗的AIS-LVO患者临床资料,根据估算肾小球过滤器(eGFR)分为RI组和非RI组,比较两组的相关资料,同时采用单因素及多因素Logistic回归分析探讨RI和其他可能的危险因素与接受EVT的AIS-LVO患者预后的相关性,运用ROC曲线及AUC分析比较RI联合其他可能的危险因素对90 d预后的预测价值。结果:本研究共纳入248例患者,多因素Logistic回归分析显示RI、基线ASPECTs、颈内动脉闭塞、过高HDL-C与90 d预后具有独立相关性(P<0.05)。RI联合过高HDL-C可以提高对90 d预后的预测能力(AUC=0.702,P<0.001)。结论:RI及过高HDL-C均是接受EVT的AIS-LVO患者90 d不良预后的独立危险因素,两者联合可以提高对90 d预后的预测能力。 展开更多
关键词 急性缺血性卒中 大血管闭塞 血管内治疗 肾功能损害 过高高密度脂蛋白胆固醇
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基于OCTA白内障术后黄斑血管密度变化的环形分区分析
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作者 杨晖 郑卓妮 +3 位作者 苟苏庆 郑宇阳 蔡剑秋 陈如 《浙江临床医学》 2024年第6期831-833,共3页
目的分析白内障术前与术后视网膜黄斑中心凹的厚度、不同层次的血管密度(VD)和中央凹无血管区(FAZ)的变化。方法回顾性分析14例(16眼)接受白内障手术患者的临床资料。分别对黄斑中心4.5 mm×4.5 mm区域行光学相干断层血管造影检查,... 目的分析白内障术前与术后视网膜黄斑中心凹的厚度、不同层次的血管密度(VD)和中央凹无血管区(FAZ)的变化。方法回顾性分析14例(16眼)接受白内障手术患者的临床资料。分别对黄斑中心4.5 mm×4.5 mm区域行光学相干断层血管造影检查,计算术前、术后1周、1个月、3个月的视网膜厚度、浅层毛细血管复合体及深层毛细血管复合体VD、FAZ面积等参数。采用自定义的环形分区分别计算并对比VD的变化。结果14例(16只眼)患者,术前术后视网膜厚度及FAZ无明显差异。浅层毛细血管复合体(SVC)的术后1周、1个月和3个月2 mm范围外的VD均值高于术前(P<0.05)。深层毛细血管复合体(DVC)术后3个月2 mm范围外VD均值高于术前(P<0.05)。结果视网膜内层VD的变化比外层VD的变化更明显。VD在外侧区域的变化比内侧区域更为明显。术后1周视网膜各层VD升高,术后1个月略有下降,3个月时仍超过基线水平。 展开更多
关键词 光学相干断层血管造影术 黄斑区 血管密度 超声乳化 区域分析
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广域SS-OCTA下早期糖尿病性视网膜病黄斑区的改变
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作者 蔡亚珍 方严 +2 位作者 崔腾 徐玥 谢驰 《安徽理工大学学报(自然科学版)》 CAS 2024年第4期89-98,共10页
目的基于广域扫频光学相干断层扫描血管成像(SS-OCTA)观察早期糖尿病性视网膜病变(DR)黄斑视网膜微循环的改变及神经节细胞内丛状层(GC-IPL)结构的变化及其相关性。方法于2023年07月至2023年08月在安徽理工大学第一附属医院眼科共招募10... 目的基于广域扫频光学相干断层扫描血管成像(SS-OCTA)观察早期糖尿病性视网膜病变(DR)黄斑视网膜微循环的改变及神经节细胞内丛状层(GC-IPL)结构的变化及其相关性。方法于2023年07月至2023年08月在安徽理工大学第一附属医院眼科共招募105例105眼DR患者,分为无DR组(NDR)53眼和轻至中度非增殖性DR组(NPDR)52眼两组,53例健康受试者作为对照组。采用SS-OCTA以黄斑为中心的12mm×12mm扫描成像并自动定量测算黄斑不同分区的浅层血管复合体(SVC)、深层血管复合体(DVC)的血管密度(VD)、灌注面积(PA),SVC的小血管密度(SVD)以及神经节细胞内从状层(GC-IPL)厚度,并进行相关性分析。结果与对照组相比,NDR组DVC中只有鼻侧象限PA差异有统计学意义(P=0.035);NPDR组除了SVC中VD的上、颞侧象限、PA的上象限、DVC中VD的鼻侧象限差异没有统计学意义(P=0.443、P=0.302、P=0.644、P=0.129),其余均有统计学意义(P<0.05)。与NDR组相比,NPDR组的SVC、DVC中平均VD、总PA以及各象限的和SVC中SVD平均以及各象限的差异均有统计学意义(P<0.05)。与对照组、NDR组相比,NPDR组鼻侧象限GC-IPL的差异均有统计学意义(P=0.020、P=0.003);与对照组相比,NDR组GC-IPL中的差异以及各象限无统计学意义(P=1.000)。在Spearman相关分析中,鼻侧象限GC-IPL与SVC中平均VD、总PA、SVD呈正相关性(r=0.438,P<0.001;r=0.417,P<0.001;r=0.439,P<0.001),中等相关;与DVC中平均VD、总PA呈正相关性(r=0.247,P=0.002;r=0.360,P<0.001),弱相关。结论随着DR进展,广域SS-OCTA可观察到视网膜微循环先代偿性增加后下降。浅层小血管的密度可作为临床前糖尿病视网膜病变早期客观检测影像学标志。早期DR视网膜微循环的改变和视网膜神经改变存在相关性。 展开更多
关键词 糖尿病性视网膜病变 广域扫频光学相干断层扫描血管成像 血管密度 血管复合体 神经节细胞内丛状层
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飞秒激光辅助与传统超声乳化术后黄斑和视盘区神经纤维层厚度及血管密度变化
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作者 周梦兰 徐正东 +4 位作者 兰长骏 杨月 罗正阳 苗壮 李彪 《国际眼科杂志》 CAS 2024年第9期1461-1465,共5页
目的:运用光学相干断层扫描血管成像(OCTA)观察飞秒激光辅助与传统超声乳化白内障术后患者黄斑和视盘区神经纤维层厚度及血管密度变化情况。方法:前瞻性非随机对照研究。纳入2022-07/10于成都东区爱尔眼科医院诊断为年龄相关性白内障患... 目的:运用光学相干断层扫描血管成像(OCTA)观察飞秒激光辅助与传统超声乳化白内障术后患者黄斑和视盘区神经纤维层厚度及血管密度变化情况。方法:前瞻性非随机对照研究。纳入2022-07/10于成都东区爱尔眼科医院诊断为年龄相关性白内障患者并住院接受手术治疗的患者65例85眼,根据患者自愿选择手术方式,分为飞秒激光辅助组23例30眼,传统超声乳化组42例55眼。于术前,术后1 d,1 mo均行OCTA检查,比较两组患者黄斑和视盘区神经纤维层厚度、血管密度及血流灌注变化。结果:两组患者术后1 mo BCVA均较术前改善,眼压均较术前降低(均P<0.01);术后1 d,1 mo,飞秒激光辅助组黄斑区神经纤维层厚度较术前增加(均P<0.05),而传统超声乳化组手术前后均无差异(均P>0.05);传统超声乳化组视盘区神经纤维层厚度、黄斑和视盘区血管密度及血流灌注与术前比较均有差异(均P<0.05),而飞秒激光辅助组均无差异(均P>0.05)。两组患者手术前后黄斑中心凹无血管区域(FAZ)面积比较均无差异(均P>0.05)。结论:飞秒激光辅助白内障手术对眼底视网膜血管影响更小。 展开更多
关键词 飞秒激光 超声乳化白内障手术 光学相干断层扫描血管成像 黄斑和视盘区血管密度
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