光学相干断层扫描诊断黄斑部视网膜前膜的评价

目的　探讨黄斑部视网膜前膜的光学相干断层扫描 (OCT)图像特征及临床应用价值。方法　对特发性黄斑前膜 9例和继发性黄斑前膜 13例患者进行经黄斑中心凹的OCT线性扫描并测量膜厚度。结果　OCT图像能清晰显示与视网膜分离或部分分离的前膜 13例 ,并可显示与视网膜紧密粘连的前膜及其对视网膜的牵拉形态改变。结论　OCT能直接客观地显示黄斑前膜横断面特征及其与玻璃体视网膜的关系并能提供定量的分析。     

Optical Coherence Tomography in Assessing Plaque Characteristics

Optical coherence tomography (OCT), a new imaging modality, has shown a superior ability in detecting and distinguishing different types of plaques (fibrous, fibrocalcific, and lipid-rich plaques), in visualizing of vascular microstructures such as intraluminal thrombi, vascular dissection, and structure of restenotic tissues, and finally in identifying vulnerable plaques, otherwise missed by intravascular ultrasound. However, limitations in the use of OCT such as poor penetration and its attenuation by blood or the clinical relevance of OCT should be clarified through further investigation, and careful attention should be paid to the future studies on OCT.     

Optical Coherence Tomography and Fibrous Cap Characterization

The pathophysiology of acute coronary syndromes has long been associated with atherosclerotic plaque rupture. Inflammation, thinning, and disruption of the fibrous cap have been implicated with the final processes leading to plaque rupture, but confirmation of these mechanisms of coronary thrombosis in humans has been hampered by the lack of imaging methods with sufficient resolution to resolve fibrous cap characterization and thickness in vivo. Intravascular optical coherence tomography (OCT) provides images with micron-level axial and lateral resolution, enabling detailed visualization of micro-structural changes of the arterial wall. The present article provides an overview of the potential role of OCT in identifying and characterizing fibrous cap morphology, thickness, and inflammation in human coronary plaques.     

视网膜前膜光学相干断层扫描图像分析

目的探讨光学相干断层扫描（OCT）检查对黄斑区视网膜前膜临床诊断和术后的评估价值。方法对在我院眼底检查拟诊或诊断为黄斑区视网膜前膜的49例患者（61眼）术前及术后进行OCT检查。结果黄斑区视网膜前膜的OCT图像表现为视网膜表面厚薄不一的高反光带，部分视网膜内表面完全紧密粘连，大部分与视网膜内层分离，多数为黄斑中心凹变浅，厚度增加，部分可伴黄斑假性裂孔、板层裂孔、黄斑囊样水肿或视网膜神经上皮脱离。术后黄斑区视网膜前膜消失，部分黄斑区神经上皮损害或黄斑部不同程度水肿。结论OCT检查可直接客观显示黄斑区前膜及术后黄斑区视网膜组织结构的改变。     

Optical Coherence Tomography: A Noninvasive Method to Assess Wound Reepithelialization

Background Accurate assessment of wound healing may require invasive tissue biopsies, limiting its clinical usefulness in humans. Optical coherence tomography (OCT) is a novel, high‐resolution method using light reflection to obtain noninvasive cross sectional imaging of biological tissues. Objectives To evaluate the utility of OCT for assessing wound reepithelialization in a porcine model. Methods The authors conducted an animal study with two domestic pigs. Excisional cutaneous wounds were created over the ventral surface of the animals using an electric dermatome set at a depth of 600 μm. The wounds were excised two or three days later and precisely marked to guide initial OCT and subsequent tissue slicing and microscopy. Comparing hematoxylin and eosin–stained histologic sections and the corresponding OCT images from each tissue sample permitted identification of the correlative micromorphology. Scatter and Bland–Altman plots were used to present the data. The primary measure of agreement was the standard deviation of the pairwise differences in percent reepithelialization between OCT and histology together with a 95% confidence interval. Results In normal skin, the epidermis was characterized by a thin, bright layer indicating a high degree of light scattering on OCT. The dermis below was characterized by a thicker, darker area indicating less scattering of light. All fresh excisional wounds lacked an outer bright layer of epidermis immediately after injury. At days 2 and 3, the wounds were partially reepithelialized. A new bright layer with intense light scattering was present on OCT corresponding to the neoepidermis on hematoxylin and eosin–stained sections. The correlation between percent reepithelialization measured with OCT and histology was 0.66 (p < 0.001), and the standard deviation of the differences was 11.0% (95% confidence interval = 8.4% to 16.1%). Conclusions OCT accurately detects the presence or absence of the epidermal layer of skin, allowing noninvasive tracking of wound reepithelialization.     

Recent Advances in the Field of Optical Coherence Tomography

Purpose of Review

The scope of this text is to critically review the most important recent advances in the field of optical coherence tomography, both from a clinical, scientific, and technical point of view.

Recent Findings

In recent years, important steps forward have been put in the field of optimization of PCI (with a focus on optimal sizing of stents and optimization of stent expansion after implantation) and the differentiation and its possible applications of various underlying morphologic characteristics of acute coronary syndrome lesions. Several efforts have been made to elucidate underlying mechanical causes of stent thrombosis, based on optical coherence tomography (OCT) imaging. This had led to the recognition of neoatherosclerosis as an important cause for very late stent thrombosis, fueling new research into this area and to the development of intracoronary devices which could be even more safe for patients on the very long term.

Summary

With an ever increasing use for clinical and scientific applications in coronary artery disease, OCT has come to a mature and solid tool in the armamentarium of the coronary artery disease specialist. With new areas deserving more intensified focus and several innovations ahead, it seems that OCT is there to defend its position as the standard intracoronary imaging modality for the next decennium.

     

外伤性黄斑病变光学相干断层成像的应用研究

目的探讨光学相干断层成像（OCT）在外伤性黄斑病变中应用的临床意义。方法对56例外伤性黄斑病变（56眼）行OCT检查,并进行图像分析。结果OCT检查显示全层黄斑孔23眼、板层黄斑孔3眼、黄斑前膜3眼、黄斑区出血8眼、神经上皮浆液性脱离5眼、出血性色素上皮脱离各4眼、黄斑水肿4眼、黄斑区神经上皮层变薄6眼。结论OCT在外伤性黄斑病变的鉴别诊断、病情监测及对其发病机制的分析研究等方面均有重要的应用价值。     

孔源性视网膜脱离术后黄斑区相干光断层扫描临床研究

目的：观察波及黄斑区的孔源性视网膜离术后各时期黄斑区相干光断层扫描图像特征及孔源性视网膜脱离患者眼轴长度与手术后视网膜下液吸收的关系,分析其与视力恢复过程的相关性。方法：对53例（53眼）波及黄斑区的孔源性视网膜脱离经巩膜外加压术后视网膜复位的患者分别于术后1周、1月、3月、6月进行相干光断层扫描检查,观察黄斑区形态变化及黄斑区视网膜下液残留情况,并将检查结果与患者病程、眼轴长度以及手术后视力恢复情况等临床资料进行了对比分析。结果：术后1周,所有病例均残留程度不等的视网膜下液,随着时间的延长,积液不断吸收。与之相对应,患者视力逐渐提高。术后3月,黄斑区视网膜下积液全部吸收累计33例,其中眼轴长度大于26 mm患者视网膜下液吸收速度较慢,差异有统计学意义（P〈0.05）。术后6月,43例患者黄斑区视网膜下积液全部吸收,仍有7例神经上皮浅脱离,3例局限性神经上皮脱离。术后6月时患者最佳矫正视力〈0.05者7眼,0.05～0.3者17眼,≥0.3者29眼。结论：光学相断层扫描能从微观角度清晰地显示视网膜复位后黄斑区形态结构的变化。巩膜外加压术后视网膜复位的患者黄斑区仍残留少量的视网膜下积液,视网膜下积液的逐步吸收能较好地解释术后视力的恢复过程。眼轴长度大于26mm患者视网膜下液吸收速度较慢。     

Update on Intracoronary Optical Coherence Tomography: a Review of Current Concepts

Purpose of review

The advent of intracoronary optical coherence tomography (OCT) has been a significant leap forward in the ability to visualize coronary structures with unprecedented resolution. However, the clinical application of this imaging modality has lagged behind rapid technological advances. One of the main reasons for the lack of wider clinical uptake has been the paucity of appropriately designed prospective randomized studies to demonstrate the impact of OCT on outcome measures after percutaneous coronary intervention (PCI).

Recent findings

Over the last couple of years, studies from large registries have shown the impact of OCT in decision-making in PCI, with several further reports providing valuable insights into the natural history of the atherosclerotic disease process and the modulating effects of therapies. Furthermore, guidance of PCI by OCT, including the appropriate use of newer generations of coronary stents, has been the focus of multiple studies.

Summary

In this contemporary review, we provide a brief overview of the recently published data and highlight the multiple areas that need further clarification as OCT is further incorporated into routine clinical practice.

     

光学相干断层扫描在青光眼早期诊断中的应用价值

目的探讨频域光学相干断层扫描(OCT)对发现和诊断早期青光眼的应用价值。方法将84例(160眼)行眼底视乳头OCT检查的患者按检查结果分为3组:疑似青光眼组(SG组,34例,68眼)、确诊青光眼早中期组(DG早中期组,40例,72眼)和正常组(10例,20只眼)。分别对各组采集的各象限(颞侧、上方、鼻侧、下方)视神经纤维层(RNFL)厚度、平均RNFL、视盘参数(水平及垂直杯盘比、杯/盘面积比)的数据进行比较;将OCT测得的各组眼的平均RNFL厚度值与视野平均缺损(MD)进行直线相关性分析。结果 SG组下方、上方象限及平均RNFL厚度,DG早中期组下方、上方、鼻侧、颞侧象限及平均RNFL厚度均明显低于正常组(均P<0.05);SG组鼻侧、颞侧RNFL厚度与正常组比较差异均无统计学意义(均P>0.05)。DG早中期组各象限(上方、下方、鼻侧)及平均RNFL厚度明显低于SG组(均P<0.05);颞侧RNFL厚度比较差异无统计学意义(P>0.05)。DG早中期组及SG组的水平及垂直杯盘比、杯/盘面积较正常组明显变大(均P<0.05)。各组的平均RNFL厚度值与MD呈高度正相关(r=0.703,P=0.00)。结论频域OCT能直观、精确地以图像及数据的方式显示视神经病变的微观层面,能检测出视野损害前的早期青光眼RNFL局限性损害,具有简便、非侵入性、重复性好、可长期随访等特点,有利于对青光眼患者的早期诊断。     

光学相干断层成像术检测视网膜厚度的误差研究

目的:探讨光学相干断层成像术(OCT)检测视网膜厚度的误差并对误差原因进行分析。方法:在1个月内随机5次对38例自愿者(共76眼)采用OTC进行视网膜神经上皮层厚度检测,测量结果采用"重复测量回归分析"方法进行统计分析。结果:各位点测量值的类内相关系数(ICC值)在0.53～0.72之间(均大于0.5),表明采用OCT测量视网膜厚度具有良好的可重复性;但各象限点视网膜厚度的ICC值略有差异,产生这些差异除了与OCT仪器的固有因素有关外,还与受检者的依从性等因素相关。结论:OCT是一种可靠的视网膜厚度定量检测工具,但还需克服诸多不利因素以提高检测的精确度。     

AGE challenge: Angle Closure Glaucoma Evaluation in Anterior Segment Optical Coherence Tomography

Angle closure glaucoma (ACG) is a more aggressive disease than open-angle glaucoma, where the abnormal anatomical structures of the anterior chamber angle (ACA) may cause an elevated intraocular pressure and gradually lead to glaucomatous optic neuropathy and eventually to visual impairment and blindness. Anterior Segment Optical Coherence Tomography (AS-OCT) imaging provides a fast and contactless way to discriminate angle closure from open angle. Although many medical image analysis algorithms have been developed for glaucoma diagnosis, only a few studies have focused on AS-OCT imaging. In particular, there is no public AS-OCT dataset available for evaluating the existing methods in a uniform way, which limits progress in the development of automated techniques for angle closure detection and assessment. To address this, we organized the Angle closure Glaucoma Evaluation challenge (AGE), held in conjunction with MICCAI 2019. The AGE challenge consisted of two tasks: scleral spur localization and angle closure classification. For this challenge, we released a large dataset of 4800 annotated AS-OCT images from 199 patients, and also proposed an evaluation framework to benchmark and compare different models. During the AGE challenge, over 200 teams registered online, and more than 1100 results were submitted for online evaluation. Finally, eight teams participated in the onsite challenge. In this paper, we summarize these eight onsite challenge methods and analyze their corresponding results for the two tasks. We further discuss limitations and future directions. In the AGE challenge, the top-performing approach had an average Euclidean Distance of 10 pixels (10 µm) in scleral spur localization, while in the task of angle closure classification, all the algorithms achieved satisfactory performances, with two best obtaining an accuracy rate of 100%. These artificial intelligence techniques have the potential to promote new developments in AS-OCT image analysis and image-based angle closure glaucoma assessment in particular.     

Introduction: Advances in Optical Coherence Tomography, Photoacoustic Imaging, and Microscopy

The editors introduce the Biomedical Optics Express feature issue, “Advances in Optical Coherence Tomography, Photoacoustic Imaging, and Microscopy,” which combines three technical areas from the 2010 Optical Society of America (OSA), Biomedical Optics (BIOMED) Topical Meeting held on 11–14 April in Miami, Florida, and includes contributions from conference attendees.OCIS codes: (170.0170) Medical optics and biotechnology, (170.4500) Optical coherence tomography, (170.5120) Photoacoustic imaging, (180.0180) MicroscopyThis special issue is one of a series of feature issues in Biomedical Optics Express. This issue focuses on recent developments and applications of high-resolution imaging technologies, which cover three of the seven technical areas in the recent OSA Biomedical Optics (BIOMED) Topical Meeting, held on April 11–14, 2010, in Miami, Florida. These three areas are Optical Coherence Tomography (OCT) and Sensing, Photoacoustic Imaging and Spectroscopy, and Microscopy, which were chaired by Xingde Li from the Johns Hopkins University (USA), by Paul Beard from the University College London (UK), and by Irene Georgakoudi from Tufts University (USA) and Jerome Mertz from Boston University (USA), respectively. This special issue includes contributions from the conference attendees of the above three technical programs. More detailed information about the BIOMED meeting can be found in a sister Special Issue of Biomedical Optics Express [1].Optical Coherence Tomography and Sensing is a traditional session in the BIOMED topical meetings. This year we received 39 contributed submissions, which covered a broad and nicely blended spectrum of the field. Most of the submissions showcased new technology developments, including new record of OCT imaging speed, new light sources, imaging contrast mechanisms, algorithms for blood vessels imaging and hemoglobin sensing, new concepts of multimodal integration, novel miniature imaging devices and others. In addition to technology development, quite a few papers reported in vivo animal model and clinical OCT applications, including retina and cornea imaging, cancer detection, and cell viability assessment.In addition to the contributed submissions, we had a plenary talk on the state-of-art OCT technology developments and applications in ophthalmology and cardiology, delivered by Dr. James Fujimoto from Massachusetts Institute of Technology. We also had two invited talks, with one presented by Dr. Robert Huber from Ludwig-Maximilians-University München on ultrahigh speed OCT imaging technologies that set the new imaging speed record, and the other one presented by Dr. Andrew Rollins from Case Western Reserve University on 3D and 4D OCT imaging of developing heart, which presented an extremely important area where OCT is making a growing impact.This special issue has three papers in the area of OCT and sensing, including (i) a multimodal platform that integrates OCT with fluorescence life time microscopy for both morphological imaging and biochemical sensing [2], (ii) a clever method to combine confocal fundus imaging with ophthalmic OCT allowing for natural co-registration and motion tracking [3], and (iii) systematic investigation on the wavelength-dependence of OCT imaging depth, particularly for 1300 nm and 1600 nm [4].The Photoacoustic Imaging and Spectroscopy session (the first such dedicated session at OSA BIOMED) generated significant interest with 35 abstract submissions. Topics encompassed new developments in photoacoustic instrumentation, multimodal techniques, nonlinear photoacoustic microscopy, and in vivo clinical and preclinical imaging applications, as well as quantitative photoacoustic image reconstruction methods. In addition to the submitted oral presentations and posters, Dr Alexander Oraevsky from TomoWave Laboratories, Inc. gave an invited talk outlining his latest work in small animal and clinical photoacoustic imaging. The three papers in this special feature include (i) a new type of ultrasound detector based on an axicon that provides an extended depth range of focus compared with conventional spherical focused transducers for use in photoacoustic microscopy [5], (ii) a means of achieving optically defined axial as well as lateral spatial resolution in photoacoustic microscopy by exploiting nonlinear transient absorption [6], and (iii) the use of an exogenous chromophore that exhibits a fluence-dependent absorption to provide a quantitative image of its concentration [7].There were 45 Microscopy contributed submissions that were presented during the poster sessions and two oral presentation sessions that focused on Advances in Nonlinear Microscopy and Novel Approaches in Microscopy. Two invited talks were delivered in these sessions by Guillaume Labroille from Ecole Polytechnique, France, on the use of pulse shaping for two-photon microscopy applications and by Alexander Egner from the Max Planck Institute for Biophysical Chemistry, Germany, on fluorescence nanoscopy. The three studies reported in detail in this special feature describe (i) the development of high-speed focal modulation microscopy using acousto-optical modulators [8], (ii) the marriage of microfluidics and optics in a microfluidic photoporation system to enable automated, high-throughput optical injection of cells [9], and (iii) the interplay of chromatic aberrations and scattering in two-photon fluorescence spectroscopic measurements performed with a GRIN-lens-based imaging set-up [10].The papers published in this special issue represent an excellent combination of different topics covered at the BIOMED conference. The editors (and the conference organization members) would like to take this opportunity to thank the attendees for their contribution to the conference and the authors for their contribution to this special issue.     

光学相干断层成像检查术应用于冠心病患者的护理

目的探讨光学相干断层成像术(optical coherence tomography,OCT)应用于冠心病患者的护理方法。方法回顾并总结64例接受OCT检查的冠心病患者的临床资料。结果 64例患者均成功完成OCT检查,检查过程中有18例(28.1%)患者出现轻度胸闷和心电图T波改变;26例(40.6%)患者心电图出现变化但无胸闷症状,血流恢复后心电图恢复到检查前水平;20例(31.3%)患者无不适感及心电图变化。结论精心、细致的护理配合对患者顺利完成OCT检查具有重要意义。