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Brain mechanism of acupuncture for children with anisometropic amblyopia: a resting functional magnetic resonance imaging study based on voxel-mirrored homotopic connectivity
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作者 Jue Wang Jing Jia +4 位作者 Yan Sun Chong-Bing Ma Yu-Zhu Chen An-Guo Liu Xing-Ke Yan 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第2期339-347,共9页
AIM:To explore the brain mechanism of acupuncture for children with anisometropic amblyopia using the voxelmirror homotopic connectivity(VMHC)analysis method of resting functional magnetic resonance imaging(rs-fMRI)te... AIM:To explore the brain mechanism of acupuncture for children with anisometropic amblyopia using the voxelmirror homotopic connectivity(VMHC)analysis method of resting functional magnetic resonance imaging(rs-fMRI)technology based on clinical effectiveness.METHODS:Eighty children with anisometropic monocular amblyopia were randomly divided into two groups:control(40 cases,1 case of shedding)and acupuncture(40 cases,1 case of shedding)groups.The control group was treated with glasses,red flash,grating,and visual stimulations,with each procedure conducted for 5min per time.Based on routine treatment,the acupuncture group underwent acupuncture of“regulating qi and unblocking meridians to bright eyes”,Jingming(BL1),Cuanzhu(BL2),Guangming(GB37),Fengchi(GB20)acupoints were taken on both sides,with the needle kept for 30min each time.Both groups were treated once every other day,three times per week,for a total of 4wk.After the treatment,the overall curative effect of the two groups and the latency and amplitude changes of P100 wave of pattern visual-evoked potential were counted.At the same time,nine children with left eye amblyopia were randomly selected from the two groups and were scanned with rsfMRI before and after treatment.The differences in the brain regions between the two groups were compared and analyzed with VMHC.RESULTS:Chi-square test showed a notable difference in the total efficiency rate between the acupuncture(94.87%)and control groups(79.49%).Regarding the P100 wave latency and amplitude,the acupuncture group had significantly shorter latency and higher amplitude of P100 wave than the control group.Moreover,the VMHC values of the bilateral temporal lobe,superior temporal gyrus,and middle temporal gyrus were notably increased in the acupuncture group after treatment.CONCLUSION:Acupuncture combined with conventional treatment can significantly improve the corrected visual acuity and optic nerve conduction in children with anisometropic amblyopia.Compared with the conventional treatment,the regulation of acupuncture on the functional activities of the relevant brain areas in the anterior cerebellum may be an effective acupuncture mechanism for anisometropic amblyopia. 展开更多
关键词 resting functional magnetic resonance imaging voxel-mirror homotopy connection anisometropic amblyopia ACUPUNCTURE
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Abruptly developed large esotropia after full time occlusion therapy in anisometropic amblyopia
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作者 Huijae Lee Ungsoo Samuel Kim 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2012年第5期650-651,共2页
Dear Sir,I am Dr. Huijae Lee, from the Seoul Ire Eye Clinic,Seoul, Korea. I write to present a case report of esotropia after occlusion therapy.Amblyopia can be caused by
关键词 TIME Abruptly developed large esotropia after full time occlusion therapy in anisometropic amblyopia
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Structural and functional alterations in the brains of patients with anisometropic and strabismic amblyopia:a systematic review of magnetic resonance imaging studies 被引量:1
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作者 Yuxia Wang Ye Wu +1 位作者 Lekai Luo Fei Li 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第11期2348-2356,共9页
Amblyopia is the most common cause of vision loss in children and can persist into adulthood in the absence of effective intervention.Previous clinical and neuroimaging studies have suggested that the neural mechanism... Amblyopia is the most common cause of vision loss in children and can persist into adulthood in the absence of effective intervention.Previous clinical and neuroimaging studies have suggested that the neural mechanisms underlying strabismic amblyopia and anisometropic amblyopia may be different.Therefore,we performed a systematic review of magnetic resonance imaging studies investigating brain alterations in patients with these two subtypes of amblyopia;this study is registered with PROSPERO(registration ID:CRD42022349191).We searched three online databases(PubMed,EMBASE,and Web of Science) from inception to April 1,2022;39 studies with 633 patients(324patients with anisometropic amblyo pia and 309 patients with strabismic amblyopia) and 580 healthy controls met the inclusion criteria(e.g.,case-control designed,pee r-reviewed articles) and were included in this review.These studies highlighted that both strabismic amblyopia and anisometropic amblyopia patients showed reduced activation and distorted topological cortical activated maps in the striate and extrastriate co rtices during tas k-based functional magnetic resonance imaging with spatial-frequency stimulus and retinotopic representations,respectively;these may have arisen from abnormal visual experiences.Compensations for amblyopia that are reflected in enhanced spontaneous brain function have been reported in the early visual cortices in the resting state,as well as reduced functional connectivity in the dorsal pathway and structural connections in the ventral pathway in both anisometro pic amblyopia and strabismic amblyopia patients.The shared dysfunction of anisometro pic amblyopia and strabismic amblyopia patients,relative to controls,is also chara cterized by reduced spontaneous brain activity in the oculomotor co rtex,mainly involving the frontal and parietal eye fields and the cerebellu m;this may underlie the neural mechanisms of fixation instability and anomalous saccades in amblyopia.With regards to specific alterations of the two forms of amblyo pia,anisometropic amblyo pia patients suffer more microstructural impairments in the precortical pathway than strabismic amblyopia patients,as reflected by diffusion tensor imaging,and more significant dysfunction and structural loss in the ventral pathway.Strabismic amblyopia patients experience more attenuation of activation in the extrastriate co rtex than in the striate cortex when compared to anisometropic amblyopia patients.Finally,brain structural magnetic resonance imaging alterations tend to be lateralized in the adult anisometropic amblyopia patients,and the patterns of brain alterations are more limited in amblyopic adults than in childre n.In conclusion,magnetic resonance imaging studies provide important insights into the brain alterations underlying the pathophysiology of amblyopia and demonstrate common and specific alte rations in anisometropic amblyo pia and strabismic amblyopia patients;these alterations may improve our understanding of the neural mechanisms underlying amblyopia. 展开更多
关键词 amblyopia ANISOMETROPIA brain function magnetic resonance imaging oculomotor system precortical pathway STRABISMUS structure visual cortex
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AB102.Image blur perception in amblyopia:beyond edges
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作者 Charlene Yang Reza Farivar Robert F.Hess 《Annals of Eye Science》 2018年第1期508-508,共1页
Background:Understanding the neurophysiological mechanisms of Amblyopia,a neurodevelopmental disorder of the visual cortex,will bring us closer to full recovery.Past findings have been contradictory.Results have shown... Background:Understanding the neurophysiological mechanisms of Amblyopia,a neurodevelopmental disorder of the visual cortex,will bring us closer to full recovery.Past findings have been contradictory.Results have shown that despite having severe acuity impairment,amblyopes can nonetheless perceive sharp edges.In this study,we explore the representation of blur through a series of image blur-discrimination and matching tasks,to understand more about the amblyopes’visual system.Methods:Monocular image blur-discrimination thresholds were measured in a spatial two-alternative forced-choice procedure whereby subjects had to decide which image was the blurriest.Subjects also had to interocularly match pictures that were identical to those used for the image blur discrimination task.Ten amblyopes,as well as a group of ten controls were under study.Results:Data on amblyopes and controls will be presented for both experiments.According to previous research that was done on blur-edge discrimination and matching,we predict that subjects’performance will follow a dipper function,that is,all observers will be better at discriminating between both images when a small amount of blur is applied rather than when the image is either sharp or very blurry.We also predict that amblyopes’blur discrimination will be noisier,but that they will paradoxically be able to match the sharpness of the images presented in the matching task.Conclusions:This would confirm our hypothesis about amblyopes’visual system,that they can represent blur levels defined by spatial frequencies that are beyond their resolution limit,and would also raise interesting questions about the visual system in general regarding the different perceptions driven by images versus edges. 展开更多
关键词 amblyopia image blur-discrimination image blur matching EDGES dipper function
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An Update of the Recent Developments on Amblyopia
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作者 Abdulmajeed Alharbi Hosam Dahaim Al Harbi 《Open Journal of Ophthalmology》 2020年第3期251-264,共14页
Amblyopia is a neurodevelopmental disorder of the visual cortex arising from abnormal visual experience early in life. Amblyopia is a major cause of impaired vision in infants and young children (prevalence around 3.5... Amblyopia is a neurodevelopmental disorder of the visual cortex arising from abnormal visual experience early in life. Amblyopia is a major cause of impaired vision in infants and young children (prevalence around 3.5%). There are different treatment options for amblyopia based on its severity and age of the patient. Traditional treatments include patching or occlusion of the dominant eye and pharmacological penalisation using Atropine (1%). Recent developments in amblyopia management have found success with the use of binocular exercises and certain modifications of glasses and contact lenses. The critical age up to which amblyopia is treatable or reversible is also being pushed up with more research. With newer advancements in amblyopia therapy, the success rate is also improving with multimodal approach. 展开更多
关键词 amblyopia Visual Circuit Anisometropic amblyopia STRABISMUS Visual Dep-rivation Reverse amblyopia occlusion Binocular Therapy Penalisation Or-thoptics
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Characterization, passive and active treatment in strabismic amblyopia: a narrative review 被引量:3
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作者 Myriam Milla David P.Pinero 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2020年第7期1132-1147,共16页
Strabismic amblyopia is characterized by a distorted spatial perception.In this condition,the neurofunctional disorder occurring during first years of life provoke several monocular and binocular anomalies such as cro... Strabismic amblyopia is characterized by a distorted spatial perception.In this condition,the neurofunctional disorder occurring during first years of life provoke several monocular and binocular anomalies such as crowding,deficits in the accommodative response,contrast sensitivity,and ocular motility abilities.The inhibition of the binocular function of the brain by the misaligned amblyopic eye induces a binocular imbalance leading to interocular suppression and the reduction or lack of stereoacuity.Passive treatments such as occlusion,optical and/or pharmacological penalization,and Bangerter foils has been demonstrated to be potentially useful treatments for strabismic amblyopia.Recent researches have proved new pharmacological options to improve and maintain visual acuity af ter occlusion treatment in strabismic amblyopia.Likewise,the active vision therapy,in the last years,is becoming a very relevant therapeutic option in combination with passive treatments,especially during and after monocular therapy,in the attempt of recovering the imbalanced binocular vision. 展开更多
关键词 amblyopia STRABISMUS occlusion vision therapy strabismic amblyopia PENALIZATION Bangerter foil
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Mechanism of Neurophysiological Treatment of Amblyopia Using Functional Magnetic Resonance Imaging
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作者 Guangming Lu Zhiqiang Zhang +2 位作者 Ping Liang Wenzhen Zhou Lin Li 《眼科学报》 2006年第3期195-201,共7页
Purpose: To research the mechanism of neurophysiological treatment of amblyopia by observing the visual cortex activation under rotating grating stimulus with functional magnetic resonance imaging (MRI), and identify ... Purpose: To research the mechanism of neurophysiological treatment of amblyopia by observing the visual cortex activation under rotating grating stimulus with functional magnetic resonance imaging (MRI), and identify the components of the activation. Methods: Nine healthy volunteers were examined using gradient-recalled echo and echo-planar imaging (GRE-EPI) pulse sequence performed at the 1.5 Tesla MRI scanner. In the block designing, rotating grating, stationary grating and luminance were plotted as task states, stationary grating, luminance and darkness as control states, respectively. The tasks of stimuli included 6 steps. Imaging processing and statistical analysis were carried out off-line using statistical parametric mapping (SPM99) software in single-subject. Results: Some individual areas of visual cortex were activated by various stimuli information supplied by rotating grating. The strong activation in the middle of occipital lobe related to the stimuli of luminance, bilateral activation of Brodmann’s 19th area related to visual motion perception, and the mild activation in the middle of occipital lobe related to form perception. Conclusion: The plotting of control state is important in bock design. The effective visual information of rotating grating includes components of luminance, visual motion perception and form perception. Functional MRI has potential as a tool for studying the physiological mechanism of visual cortex. 展开更多
关键词 Neurophysiological treatment of amblyopia Visual cortex Functional magnetic resonance imaging
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Imaging characteristics and treatment strategies for carotid artery occlusion caused by skull base fracture:Three case reports
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作者 Pei-Xin Shangguan Ke-Chun Zhou 《World Journal of Clinical Cases》 SCIE 2024年第15期2664-2671,共8页
BACKGROUND Traumatic internal carotid artery(ICA)occlusion is a rare complication of skull base fractures,characterized by high mortality and disability rates,and poor prognosis.Therefore,timely discovery and correct ... BACKGROUND Traumatic internal carotid artery(ICA)occlusion is a rare complication of skull base fractures,characterized by high mortality and disability rates,and poor prognosis.Therefore,timely discovery and correct management are crucial for saving the lives of such patients and improving their prognosis.This article retrospectively analyzed the imaging and clinical data of three patients,to explore the imaging characteristics and treatment strategies for carotid artery occlusion,combined with severe skull base fractures.CASE SUMMARY This case included three patients,all male,aged 21,63,and 16 years.They underwent plain film skull computed tomography(CT)examination at the onset of their illnesses,which revealed fractures at the bases of their skulls.Ultimately,these cases were definitively diagnosed through CT angiography(CTA)examinations.The first patient did not receive surgical treatment,only anticoagulation therapy,and recovered smoothly with no residual limb dysfunction(Case 1).The other two patients both developed intracranial hypertension and underwent decompressive craniectomy.One of these patients had high intracranial pressure and significant brain swelling postoperatively,leading the family to choose to take him home(Case 2).The other patient also underwent decompressive craniectomy and recovered well postoperatively with only mild limb motor dysfunction(Case 3).We retrieved literature from PubMed on skull base fractures causing ICA occlusion to determine the imaging characteristics and treatment strategies for this type of disease.CONCLUSION For patients with cranial trauma combined with skull base fractures,it is essential to complete a CTA examination as soon as possible,to screen for blunt cerebrovascular injury. 展开更多
关键词 Skull base fracture Traumatic internal carotid artery occlusion Blunt cerebrovascular injury Imaging Case report
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Apparent diffusion coefficient evaluation for secondary changes in the cerebellum of rats after middle cerebral artery occlusion 被引量:3
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作者 Yunjun Yang Lingyun Gao +5 位作者 Jun Fu Jun Zhang Yuxin Li Bo Yin Weijian Chen Daoying Geng 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第31期2942-2950,共9页
Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron emission tomography an... Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron emission tomography and single photon emission CT. However, these methods are expensive and radioactive. Thus, the present study quantified the changes of infarction core and remote regions after unilateral middle cerebral artery occlusion using apparent diffusion coefficient values. Diffu- sion-weighted imaging showed that the area of infarction core gradually increased to involve the cerebral cortex with increasing infarction time. Diffusion weighted imaging signals were initially in- creased and then stabilized by 24 hours. With increasing infarction time, the apparent diffusion co- efficient value in the infarction core and remote bilateral cerebellum both gradually decreased, and then slightly increased 3-24 hours after infarction. Apparent diffusion coefficient values at remote regions (cerebellum) varied along with the change of supratentorial infarction core, suggesting that the phenomenon of diaschisis existed at the remote regions. Thus, apparent diffusion coefficient values and diffusion weighted imaging can be used to detect early diaschisis. 展开更多
关键词 neural regeneration brain injury cerebral ischemia cerebral infarction magnetic resonanceimaging apparent diffusion coefficient middle cerebral artery occlusion diffusion weighted imaging infarction core remote regions DIASCHISIS grants-supported paper NEUROREGENERATION
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Inhibition of Notch 1 signaling in the subacute stage after stroke promotes striatal astrocyte-derived neurogenesis 被引量:4
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作者 Xiao-Zhu Hao Cheng-Feng Sun +5 位作者 Lu-Yi Lin Chan-Chan Li Xian-Jing Zhao Min Jiang Yan-Mei Yang Zhen-Wei Yao 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第8期1777-1781,共5页
Inhibition of Notch1 signaling has been shown to promote astrocyte-derived neurogenesis after stroke.To investigate the regulatory role of Notch1 signaling in this process,in this study,we used a rat model of stroke b... Inhibition of Notch1 signaling has been shown to promote astrocyte-derived neurogenesis after stroke.To investigate the regulatory role of Notch1 signaling in this process,in this study,we used a rat model of stroke based on middle cerebral artery occlusion and assessed the behavior of reactive astrocytes post-stroke.We used theγ-secretase inhibitor N-[N-(3,5-diuorophenacetyl)-1-alanyl]-S-phenylglycine t-butylester(DAPT)to block Notch1 signaling at 1,4,and 7 days after injury.Our results showed that only administration of DAPT at 4 days after stroke promoted astrocyte-derived neurogenesis,as manifested by recovery of white matter fiber bundle integrity on magnetic resonance imaging,which is consistent with recovery of neurologic function.These findings suggest that inhibition of Notch1 signaling at the subacute stage post-stroke mediates neural repair by promoting astrocyte-derived neurogenesis. 展开更多
关键词 ASTROCYTE diffusion kurtosis imaging magnetic resonance imaging middle cerebral artery occlusion N-[N-(3 5-diuorophenacetyl)-1-alanyl]-Sphenylglycine t-butylester neural repair NEUROGENESIS neuron Notch1 signaling subacute stage
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红外地面目标智能抗遮挡跟踪算法研究
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作者 张鹏 张凯 杨尧 《西北工业大学学报》 EI CAS CSCD 北大核心 2024年第4期726-734,共9页
针对背景遮挡导致红外地面目标跟踪失败的问题,提出了一种基于改进轨迹预测网络的红外地面目标抗遮挡跟踪器。提出了遮挡判断准则,准确判断红外地面目标的遮挡情况;改进BiTrap轨迹预测网络,一方面通过孪生网络结构引入速度信息,采用单... 针对背景遮挡导致红外地面目标跟踪失败的问题,提出了一种基于改进轨迹预测网络的红外地面目标抗遮挡跟踪器。提出了遮挡判断准则,准确判断红外地面目标的遮挡情况;改进BiTrap轨迹预测网络,一方面通过孪生网络结构引入速度信息,采用单向预测的方法,提出了SiamTrap轨迹预测网络,提高了轨迹预测的精度;另一方面,通过改进训练方法和应用方法,可以更准确地预测地面目标的轨迹。对于短期遮挡,利用SiamTrap网络基于时间上下文信息预测目标遮挡位置。对于长期遮挡,提出了搜索扩展策略来处理真实目标信息缺乏导致的预测误差积累。提出了“二次判定”准则,实现了目标的精确捕获和正常跟踪。在含有遮挡的红外目标跟踪序列上对算法进行了对比测试。与基准跟踪器相比,文中所提算法在OPE评价指标下,成功率和准确率分别提高了5.2%和5.9%。这表明文中算法在应对红外地面目标被遮挡情况下具有良好的鲁棒性。 展开更多
关键词 红外图像 目标跟踪 轨迹预测 抗遮挡
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A Rare Cause of Leukocoria in Children: Persistent Hyperplastic Primary Vitreous
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作者 Prudence Ada Assoumou Davy Alex Mouinga Abayi +5 位作者 Yoan Mboussou Annick Kougou Ntoutoume Helene Nyinko Aboughe Olive Matsanga Tatiana Harly Mba Aki Emmanuel Mve Mengome 《Open Journal of Ophthalmology》 2024年第1期63-68,共6页
Introduction: Leukocoria, a whitish pupillary reflection, is a common warning sign of various pediatric ocular pathologies, including Persistent hyperplastic primary vitreous (PHVP). This case report describes the obs... Introduction: Leukocoria, a whitish pupillary reflection, is a common warning sign of various pediatric ocular pathologies, including Persistent hyperplastic primary vitreous (PHVP). This case report describes the observation of a 3-year-old child with melanoderma, presenting with a white spot in the left eye since birth. Observation: Uncorrected distance visual acuity was 2/10 in the right eye and hand movements were perceived at 2 meters in the left eye. Examination of the anterior segment in the left eye revealed leukocoria and microphthalmia. The fundus examination was normal in the right eye but revealed a white mass extending from the center of the optic disc towards the temporal region in the left eye. Ocular imaging, including ocular ultrasound and optical coherence tomography, confirmed the diagnosis of PHVP, illustrated by a residual white mass at the center of the optic disc in the left eye. Conclusion: PHVP should be considered in the presence of leukocoria in a child, with urgent exclusion of retinoblastoma. This observation underscores the importance of early diagnosis for appropriate management. . 展开更多
关键词 PHVP LEUKOCORIA amblyopia Ocular Imaging CHILDHOOD
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基于上下文提取与注意力融合的遮挡服装图像分割
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作者 顾梅花 花玮 +1 位作者 董晓晓 张晓丹 《纺织学报》 EI CAS CSCD 北大核心 2024年第5期155-164,共10页
针对遮挡服装图像分割准确率低的问题,提出一种融合上下文提取与注意力机制的遮挡服装图像实例分割方法。以Mask R-CNN为基础网络,首先采用上下文提取模块优化ResNet的输出特征,通过融合不同速率的多路径特征从多个感受野中捕获图像的... 针对遮挡服装图像分割准确率低的问题,提出一种融合上下文提取与注意力机制的遮挡服装图像实例分割方法。以Mask R-CNN为基础网络,首先采用上下文提取模块优化ResNet的输出特征,通过融合不同速率的多路径特征从多个感受野中捕获图像的上下文信息,强化遮挡服装特征表示的识别及提取能力;然后引入通道注意力机制与空间注意力机制的残差连接,自适应地专注于捕捉遮挡服装图像的空间和通道维度上的语义相互依赖关系,降低上下文提取模块在处理特征图时因冗余的上下文关系扩大造成误定位与误识别的概率;最后,采用目标检测损失函数CIoU计算原理作为非极大值抑制的评判标准,关注预测框和真实框的重叠与非重叠区域,最大程度地选择遮挡服装的最优目标框,使预测框更加贴近真实框。结果表明,与其它方法相比,改进方法显著改善了不同遮挡程度服装图像的误分割现象,能提取出更精确的服装实例,其对遮挡服装图像的平均分割精度比原模型提升了4.4%。 展开更多
关键词 图像分割 遮挡服装 上下文提取 注意力机制 CIoU计算原理
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彩色多期CT血管成像对脑大、中动脉闭塞性脑梗死的诊断价值
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作者 徐勤 徐烨 +6 位作者 祝唯 敬文斌 杨琛 黄其军 苗涵 敬诚功 田萌 《医学影像学杂志》 2024年第6期9-13,共5页
目的探讨彩色多期CT血管成像(ColorViz mCTA)对大、中动脉闭塞性脑梗死的诊断价值。方法选取本院急性缺血性脑卒中患者306例,均完成多期CTA及MRI-DWI检查。多期CTA血管信息由FastStroke软件汇总。对比ColorViz mCTA对于大、小梗死灶的... 目的探讨彩色多期CT血管成像(ColorViz mCTA)对大、中动脉闭塞性脑梗死的诊断价值。方法选取本院急性缺血性脑卒中患者306例,均完成多期CTA及MRI-DWI检查。多期CTA血管信息由FastStroke软件汇总。对比ColorViz mCTA对于大、小梗死灶的检出差异性,分析ColorViz mCTA与区别大、小病灶之间的相关性,利用ROC曲线评价ColorViz mCTA对区分大、小急性脑梗塞灶的诊断价值。结果共检出323个病灶,其中大、中动脉闭塞性梗死灶共190个,小动脉闭塞性脑梗死灶133个。病灶越大,ColorViz mCTA检出率越高(P<0.001),并且ColorViz mCTA与病灶大小有显著相关性(r=0.749,P<0.001);ColorViz mCTA区分大、小病灶曲线下面积(AUC)为0.933(P<0.001),当病灶面积等于2.53 cm2时,ColorViz mCTA具有最大诊断效能,敏感度为91.1%,特异度为86.1%。结论利用ColorViz mCTA可对脑大、中动脉闭塞性脑梗死针对性诊断。 展开更多
关键词 动脉闭塞性脑梗死 体层摄影术 X线计算机 磁共振成像
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融合双域特征均衡的遥感图像道路提取
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作者 徐虹 杨莹洁 +3 位作者 文武 吴蔚 王岩 孔维华 《电讯技术》 北大核心 2024年第6期878-886,共9页
当前遥感图像道路提取模型仍在很大程度上受道路植被遮挡所影响,导致网络模型对道路信息误判。为此,基于双域特征均衡提出了一种不受遮挡物影响的道路提取方法,高效地实现植被遮挡下的道路提取。具体而言,提出了一种新的道路提取卷积神... 当前遥感图像道路提取模型仍在很大程度上受道路植被遮挡所影响,导致网络模型对道路信息误判。为此,基于双域特征均衡提出了一种不受遮挡物影响的道路提取方法,高效地实现植被遮挡下的道路提取。具体而言,提出了一种新的道路提取卷积神经网络,该网络由去除遮挡子网络和道路提取子网络组成。在去除遮挡子网络中嵌入一个分层卷积模块用于提取输入图像的深层结构特征和浅层纹理特征,以及双域均衡模块用于特征还原,以此去除目标道路上的遮挡物。道路提取子网络用于对去除遮挡后的道路结构进行精细的分割,得到准确性更高的道路提取结果。通过在四川西南农村地区的遥感数据集上进行大量实验,结果显示基于双域特征均衡的方法相较于其他遥感图像道路提取方法在像素精确度(Overall Accuracy, OA)和交并比(Intersection over Union, IoU)指标上达到了最高,分别是98.16%和85.38%。 展开更多
关键词 遥感图像 道路提取 道路遮挡 深度学习 卷积神经网络(CNN) 双域均衡
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基于光流与多尺度上下文的图像序列运动遮挡检测
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作者 冯诚 张聪炫 +2 位作者 陈震 李兵 黎明 《自动化学报》 EI CAS CSCD 北大核心 2024年第9期1854-1865,共12页
针对非刚性运动和大位移场景下运动遮挡检测的准确性与鲁棒性问题,提出一种基于光流与多尺度上下文的图像序列运动遮挡检测方法.首先,设计基于扩张卷积的多尺度上下文信息聚合网络,通过图像序列多尺度上下文信息获取更大范围的图像特征... 针对非刚性运动和大位移场景下运动遮挡检测的准确性与鲁棒性问题,提出一种基于光流与多尺度上下文的图像序列运动遮挡检测方法.首先,设计基于扩张卷积的多尺度上下文信息聚合网络,通过图像序列多尺度上下文信息获取更大范围的图像特征;然后,采用特征金字塔构建基于多尺度上下文与光流的端到端运动遮挡检测网络模型,利用光流优化非刚性运动和大位移区域的运动检测遮挡信息;最后,构造基于运动边缘的网络模型训练损失函数,获取准确的运动遮挡边界.分别采用MPI-Sintel和KITTI测试数据集对所提方法与现有的代表性方法进行实验对比与分析.实验结果表明,所提方法能够有效提高运动遮挡检测的准确性和鲁棒性,尤其在非刚性运动和大位移等困难场景下具有更好的遮挡检测鲁棒性. 展开更多
关键词 图像序列 遮挡检测 深度学习 多尺度上下文 非刚性运动
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基于多特征融合和几何感知网络的光场图像编码
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作者 刘发国 白晓琦 +2 位作者 张倩 王斌 司文 《上海大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第4期669-681,共13页
为了克服基于单一视差合成的光场图像编码方法在遮挡区域无法恢复纹理细节的问题,提出一种基于多特征融合和几何感知网络的光场图像编码方法,以进一步提升遮挡场景下光场图像的压缩性能.首先,对密集光场稀疏采样,使用通用视频编码器(ver... 为了克服基于单一视差合成的光场图像编码方法在遮挡区域无法恢复纹理细节的问题,提出一种基于多特征融合和几何感知网络的光场图像编码方法,以进一步提升遮挡场景下光场图像的压缩性能.首先,对密集光场稀疏采样,使用通用视频编码器(versatile video coding,VVC)对稀疏光场进行压缩;然后,在解码端使用2个关键分支模块,即视差估计模块和空间角度联合卷积模块,以获取光场图像全局的几何信息,确保在密集纹理和遮挡区域能够更充分地恢复特征;最后,为了挖掘2个分支融合特征的结构信息,构建了双向视图的堆栈结构,并运用几何感知的细化网络以重建高质量的密集光场.实验结果表明,与已有国际上流行的光场图像编码方法相比,所提出的方法具有显著优势. 展开更多
关键词 光场图像编码 遮挡区域 多特征融合 几何感知
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动脉自旋标记联合区域性动脉自旋标记技术评估单侧大脑中动脉重度狭窄或闭塞患者侧支代偿
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作者 刘蒋静 李晨 +2 位作者 林斌 王玲廷 周智鹏 《中国医学影像技术》 CSCD 北大核心 2024年第4期526-530,共5页
目的 观察动脉自旋标记(ASL)联合区域性ASL(t-ASL)技术评估单侧大脑中动脉(MCA)重度狭窄或闭塞患者侧支代偿的价值。方法 回顾性选取52例单侧MCA重度狭窄或闭塞患者(病变组),根据相对脑血流量(rCBF)将其进一步分为侧支循环不良亚组(n=23... 目的 观察动脉自旋标记(ASL)联合区域性ASL(t-ASL)技术评估单侧大脑中动脉(MCA)重度狭窄或闭塞患者侧支代偿的价值。方法 回顾性选取52例单侧MCA重度狭窄或闭塞患者(病变组),根据相对脑血流量(rCBF)将其进一步分为侧支循环不良亚组(n=23)及良好亚组(n=29);以55名健康体检者为对照组。基于ASL[标记后延迟时间(PLD)=1 525、2 525 ms]和t-ASL图像比较组间及病变组内亚组间脑血流量(CBF)、rCBF及CBF差值(PLD 2 525 ms下CBF-PLD 1 525 ms下CBF),观察侧支代偿来源;以Kendall相关性分析评估各参数与代偿的相关性。结果 病变组患侧与对照组左侧CBF、CBF差值的差异及组间rCBF差异均有统计学意义(P均<0.001),且2组PLD=2 525 ms下CBF均大于PLD=1 525 ms(P均<0.05),病变组患侧CBF均小于对侧(P均<0.05)。病变组内2亚组间CBF差值、患侧CBF及rCBF差异(P均<0.001),以及侧支无代偿和对侧颈内动脉(ICA)+椎基底动脉(VBA)代偿占比差异均有统计学意义(P均<0.05)。病变组rCBF(PLD=2 525 ms)与存在VBA侧支代偿呈低度正相关(r=0.397,P=0.004)。结论 ASL联合t-ASL有助于评估单侧MCA狭窄或闭塞患者侧支代偿情况。 展开更多
关键词 大脑中动脉 狭窄 闭塞 侧支循环 动脉自旋标记 灌注成像
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双参数3D动脉自旋标记灌注成像对大脑中动脉慢性闭塞患者血供情况评价及与脑梗死面积关系研究 被引量:1
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作者 王丽坤 尹继磊 +1 位作者 刘海静 郑园园 《中国医学装备》 2024年第2期64-69,共6页
目的:探讨双参数3D动脉自旋标记灌注成像(3D-ASL)对大脑中动脉慢性闭塞(CMCAO)患者血供情况的评价及与脑梗死面积的关系。方法:选取2019年4月至2021年12月邯郸市中心医院收治的112例单侧CMCAO患者,根据数字减影血管造影(DSA)检查结果将... 目的:探讨双参数3D动脉自旋标记灌注成像(3D-ASL)对大脑中动脉慢性闭塞(CMCAO)患者血供情况的评价及与脑梗死面积的关系。方法:选取2019年4月至2021年12月邯郸市中心医院收治的112例单侧CMCAO患者,根据数字减影血管造影(DSA)检查结果将其分为大脑前动脉(ACA)脑膜支代偿(LMA)的代偿组(50例)和无代偿组(62例)。分析弥散张量成像(DWI)、磁共振血管成像(MRA)以及双参数3D-ASL检测结果,对比两组临床资料、3D-ASL参数及脑梗死发生情况,分析代偿情况影响因素,根据脑血流量值[标记后延迟时间(PLD)=1.5 s、2.5 s]绘制CMCAO患者LMA诊断价值的受试者工作特征(ROC)曲线,对比不同脑梗死面积患者3D-ASL参数,并分析3D-ASL参数与脑梗死面积的关系。结果:CMCAO患者患侧表观弥散系数(ADC)为0.31±0.10、脑血流量值1.5 s和2.5 s分别为25.67±4.25和54.09±4.49,且均低于健侧,差异有统计学意义(t=27.591、34.210、3.913,P<0.05);代偿组患者的脑血流量值分别为1.5 s和2.5 s,与无代偿组相比,差异有统计学意义(t=5.584、4.090,P<0.05);logistic回归分析显示年龄、卒中、脑梗死面积、脑血流量值1.5 s和2.5 s均为CMCAO患者LMA情况的影响因素(OR=4.187、6.604、0.482、5.681、5.807,P<0.05);ROC曲线显示,PLD为1.5 s和2.5 s时,3D-ASL诊断LMA的曲线下面积(AUC)分别为0.720、0.812;代偿组正常及腔隙性脑梗死比例高于无代偿组,中小梗死及大面积脑梗死比例低于无代偿组,差异有统计学意义(t=28.062,P<0.05);不同脑梗死面积患者脑血流量值(1.5 s)相比,差异有统计学意义(t=0.202,P<0.05);3D-ASL参数脑血流量值(1.5 s)与脑梗死面积呈负相关(r=-0.261,P<0.05)。结论:双参数3D-ASL可无创、直观地评估单侧CMCAO患者LMA代偿状况,患侧大脑中动脉(MCA)血流灌注与脑梗死面积相关,PLD为1.5 s时,可对此进行敏感反应,为临床诊治及疗效判断提供客观可靠的依据。 展开更多
关键词 双参数 3D动脉自旋标记灌注成像(3D-ASL) 大脑中动脉慢性闭塞(CMCAO) 标记后延迟时间 脑梗死面积
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适应遮挡条件下奶油生菜的实例分割方法研究
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作者 韩江枫 杨意 +3 位作者 郑鸿燊 刘厚诚 琚俊 辜松 《农机化研究》 北大核心 2024年第8期80-84,共5页
利用机器视觉技术测量生菜的表型参数对探索生菜的生长规律有着非常重要的意义,而构建生菜个体的识别及轮廓分割算法是实现表型参数精准测量的重要前提;但是,在生菜培育至采收期,俯视图下生菜个体间叶片相互重叠遮挡,对个体识别和轮廓... 利用机器视觉技术测量生菜的表型参数对探索生菜的生长规律有着非常重要的意义,而构建生菜个体的识别及轮廓分割算法是实现表型参数精准测量的重要前提;但是,在生菜培育至采收期,俯视图下生菜个体间叶片相互重叠遮挡,对个体识别和轮廓分割造成很大的阻碍。为此,改进了Mask R-CNN神经网络模型,掩膜分支采用class-agnostic模式,以ResNeXt50联合FPN替换原有的卷积主干,实现了遮挡条件下奶油生菜的个体识别和轮廓分割。为了对改进模型的分割精度进行验证分析,采用平均精度AP75和平均检测耗时作为评价指标,与原始Mask R-CNN、DeepMask、MNC分割模型在不同程度遮挡测试集上设置对比试验。结果表明:改进模型的平均精度达到98.7%,相比原模型提高了约4%,且在重度遮挡测试集上依然能够保持良好的分割精度。研究结果可为遮挡条件下植物叶片的识别和分割提供算法参考,也可为奶油生菜的表型参数提取提供技术支持。 展开更多
关键词 奶油生菜 轮廓分割 遮挡 Mask R-CNN 深度学习 图像处理
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