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    1. Automated Segmentation and Quantification of Drusen in Fundus and Optical Coherence Tomography Images for Detection of ARMD

      Automated Segmentation and Quantification of Drusen in Fundus and Optical Coherence Tomography Images for Detection of ARMD

      Age-related macular degeneration (ARMD) is one of the most common retinal syndromes that occurs in elderly people. Different eye testing techniques such as fundus photography and optical coherence tomography (OCT) are used to clinically examine the ARMD-affected patients. Many researchers have worked on detecting ARMD from fundus images, few of them also worked on detecting ARMD from OCT images. However, there are only few systems that establish the correspondence between fundus and OCT images to give an accurate prediction of ARMD pathology. In this paper, we present fully automated decision support system that can automatically detect ARMD by establishing correspondence ...

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    2. Evaluation of anterior chamber parameters with spectral-domain optical coherence tomography

      Evaluation of anterior chamber parameters with spectral-domain optical coherence tomography

      Purpose To evaluate several anterior chamber parameters in healthy young adults using spectral-domain optical coherence tomography and to describe the repeatability and reproducibility of this method. Study design Prospective clinical study. Methods Fifty-two eyes of 52 healthy volunteers were enrolled. Manual measurements of the anterior chamber angle (ACA 500 and ACA 750 ), angle opening distance (AOD 500 and AOD 750 ), angle-to-angle distance (ATA), anterior chamber width (ACW), and lens vault (LV) were obtained. Results The mean nasal ACA 500 was 44.87 ± 12.92°; ACA 750 , 43.94 ± 10.41°; AOD 500 , 672.54 ± 270.19 µm; AOD 750, 881 ...

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    3. Inspection of the Human Retina by Optical Coherence Tomography (Book Chapter)

      Inspection of the Human Retina by Optical Coherence Tomography (Book Chapter)

      Optical coherence tomography (OCT) is a high-resolution, three-dimensional, noninvasive imaging modality to examine the human retina. Since the introduction of spectral domain (SD-) OCT—the currently most used variant of OCT—previously unknown details of in vivo retinal morphology of a broad variety of pathologies have become visible. This chapter explains the basic principles of the OCT technology, deals with possible pitfalls in OCT examination or analysis, and hints at the use of OCT technology in functional imaging.

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    4. AMD Classification in Choroidal OCT Using Hierarchical Texton Mining

      AMD Classification in Choroidal OCT Using Hierarchical Texton Mining

      In this paper, we propose a multi-step textural feature extraction and classification method, which utilizes the feature learning ability of Convolutional Neural Networks (CNN) to extract a set of low level primitive filter kernels, extracts spatial information using clustering and Local Binary Patterns (LBP) and then generalizes the discriminative power by forming a histogram based descriptor. It integrates the concept of hierarchical texton mining and data driven kernel learning into a uniform framework. The proposed method is applied to a practical medical diagnosis problem of classifying different stages of Age-Related Macular Degeneration (AMD) using a dataset comprising long-wavelength Optical Coherence ...

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    5. Optical Coherence Tomography: A Review (Book Chapter)

      Optical Coherence Tomography: A Review (Book Chapter)

      Optical coherence tomography (OCT), with polarization-sensitive (PS), Doppler, and autofluorescence (AF) capabilities, is emerging as a promising bronchoscopic diagnostic tool. In the upper and central airways, it allows accurate real-time airway measurements to assist bronchoscopic assessment of obstructive sleep apnea, severity of tracheomalacia, airway stenosis, or extent of tumor involvement into the bronchial wall or distally beyond the bronchoscopic view. OCT can visualize cellular and extracellular structures at and below the tissue surface with near histologic resolution as well as to provide three-dimensional imaging of the airways. Blood vessels in the bronchial wall or peribronchial space can be displayed using ...

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    6. Very early neointimal coverage of new biodegradable polymer drug-eluting stent compared with durable polymer everolimus-eluting stent evaluated by optical frequency domain imaging

      Very early neointimal coverage of new biodegradable polymer drug-eluting stent compared with durable polymer everolimus-eluting stent evaluated by optical frequency domain imaging

      Polymeric component is associated with the increased risk of delayed vessel healing and stent endothelialization. We aimed to clarify neointimal coverage within 1 month after implantation of the new-generation abluminal biodegradable polymer (BP) drug-eluting stent (DES) compared with the second-generation durable polymer (DP) everolimus-eluting stent (EES). Between November 2015 and October 2016, 32 BP-DES and 25 DP-EES were evaluated by optical frequency domain imaging (OFDI) within 1 month after the procedure. The average interval to follow-up OFDI was not significantly different between the groups (16.3 ± 7.7 days in BP-DES vs. 15.4 ± 7.4 days in DP-EES, P ...

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    7. Automated detection of exudative age-related macular degeneration in spectral domain optical coherence tomography using deep learning

      Automated detection of exudative age-related macular degeneration in spectral domain optical coherence tomography using deep learning

      Purpose Our purpose was to use deep learning for the automated detection of age-related macular degeneration (AMD) in spectral domain optical coherence tomography (SD-OCT). Methods A total of 1112 cross-section SD-OCT images of patients with exudative AMD and a healthy control group were used for this study. In the first step, an open-source multi-layer deep convolutional neural network (DCNN), which was pretrained with 1.2 million images from ImageNet, was trained and validated with 1012 cross-section SD-OCT scans (AMD: 701; healthy: 311). During this procedure training accuracy, validation accuracy and cross-entropy were computed. The open-source deep learning framework TensorFlow™ (Google ...

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    8. In-stent fractional flow reserve variations and related optical coherence tomography findings: the FFR–OCT co-registration study

      In-stent fractional flow reserve variations and related optical coherence tomography findings: the FFR–OCT co-registration study

      We sought to assess in-stent variations in fractional flow reserve (FFR) in patients with previous percutaneous coronary intervention (PCI) and to associate any drop in FFR with findings by optical coherence tomography (OCT) imaging. Suboptimal post-PCI FFR values were previously associated with poor outcomes. It is not known to which extent in-stent pressure loss contributes to reduced FFR. In this single-arm observational study, 26 patients who previously underwent PCI with drug-eluting stent or scaffold implantation were enrolled. Motorized FFR pullback during continuous intravenous adenosine infusion and OCT assessments was performed. Post-PCI FFR < 0.94 was defined as suboptimal. At a ...

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    9. Coronary Imaging and Physiology (Textbook)

      Coronary Imaging and Physiology (Textbook)

      Although the guideline of the European Society of Cardiology has recommended that optical coherence tomography (OCT) may be considered in selected patients during percutaneous coronary intervention (PCI) [1], data regarding OCT guidance are limited (Table 14.1). In this chapter, clinical evidences and benefits of OCT-guided PCI will be discussed. This book is intended as a guide for all cardiologists who are interested in coronary imaging and physiology, a sound understanding of which is vital for the optimal performance of appropriate coronary interventions. The basics of each relevant modality are presented, with clear explanation of clinical utility and evaluation of ...

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    10. A data-acquisition and control system for spectral-domain optical coherence tomography with a speed of 91 912 A-scans/s based on a USB 3.0 interface

      A data-acquisition and control system for spectral-domain optical coherence tomography with a speed of 91 912 A-scans/s based on a USB 3.0 interface

      We describe a system of optical spectrum registration at the output of an interferometer with controlled phase shifts for an experimental device intended for visualizing the internal structure of an optically turbid specimen, using the method of spectral domain optical coherence tomography. A device for spectral domain optical coherence tomography based on a common-path optical scheme with a USB 3.0 interface for inputting data into a computer has been developed. An imaging speed of 91 912 A-scans/s has been attained. At the achieved speed, a series of live experiments were carried out to visualize the internal structure of ...

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    11. Impact of lesion complexity on long-term vascular response to cobalt–chromium everolimus-eluting stent: five-year follow-up optical coherence tomography study

      Impact of lesion complexity on long-term vascular response to cobalt–chromium everolimus-eluting stent: five-year follow-up optical coherence tomography study

      The impact of lesion complexity on long-term vascular response to cobalt–chromium everolimus-eluting stent (CoCrEES) remains unclear. We sought to evaluate them using optical coherence tomography (OCT). A total of 47 patients with 58 lesions treated only with CoCrEES and no target-vessel events within 5 years after implantation were prospectively enrolled and underwent 5-year follow-up OCT. Quantitative parameters and qualitative characteristics of the neointima were evaluated using multilevel logistic or linear regression models with random effects at three levels: lesion, cross-section (CS), and strut. According to the lesion complexity, the lesions were classified into the two groups: the complex lesion ...

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    12. OCT Angiography: an Upcoming Non-invasive Tool for Diagnosis of Age-Related Macular Degeneration

      OCT Angiography: an Upcoming Non-invasive Tool for Diagnosis of Age-Related Macular Degeneration

      Purpose The purpose of this study was to review the most recent findings, characteristics, faults, and future perspectives of optical coherence tomography angiography (OCTA) in age-related macular degeneration (AMD). Recent Findings In dry AMD, OCTA is useful on the evaluation of choriocapillaris perfusion and detection of naïve quiescent non-exudative choroidal neovascularization (CNV). In wet AMD, OCTA can provide detailed anatomic and morphologic information of CNVs, which may help to understand why and how they develop and become active. In other hand, the many artifacts present in OCTA images may lead to misinterpretation and misdiagnosis. Summary OCTA is a still ...

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    13. 3D Mapping of Choroidal Thickness from OCT B-Scans

      3D Mapping of Choroidal Thickness from OCT B-Scans

      The choroid is the middle layer of the eye globe located between the retina and the sclera. It is proven that choroidal thickness is a sign of multiple eye diseases. Optical Coherence Tomography (OCT) is an imaging technique that allows the visualization of tomographic images of near surface tissues like those in the eye globe. The automatic calculation of the choroidal thickness reduces the subjectivity of manual image analysis as well as the time of large scale measurements. In this paper, a method for the automatic estimation of the choroidal thickness from OCT images is presented. The pre-processing of the ...

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    14. Multi-layer 3D Simultaneous Retinal OCT Layer Segmentation: Just-Enough Interaction for Routine Clinical Use

      Multi-layer 3D Simultaneous Retinal OCT Layer Segmentation: Just-Enough Interaction for Routine Clinical Use

      All current fully automated retinal layer segmentation methods fail in some subset of clinical 3D Optical Coherence Tomography (OCT) datasets, especially in the presence of appearance-modifying retinal diseases like Age-related Macular Degeneration (AMD), Diabetic Macular Edema (DME), and others. In the presence of local or regional failures, the only current remedy is to edit the obtained segmentation in a slice-by-slice manner. This is a very tedious and time-demanding process, which prevents the use of quantitative retinal image analysis in clinical setting. In turn, the non-existence of reliable retinal layer segmentation methods substantially limits the use of precision medicine concepts in ...

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    15. Optical Coherence Tomography Denoising by Means of a Fourier Butterworth Filter-Based Approach

      Optical Coherence Tomography Denoising by Means of a Fourier Butterworth Filter-Based Approach

      Optical Coherence Tomography (OCT) is affected by ubiquitous speckle noise that difficult the visualization and analysis of the retinal structures. Any denoising strategy should be able to remove efficiently the noise as well as preserves clinical information contained in the images. This information is crucial to analyses the retinal layer tissue that allows the posterior analysis and recognition of relevant diseases as macular edema or diabetic retinopathy. To address this issue, a method based on the Fourier Butterworth filter combined with a contrast enhancement and a histogram regularization was developed in order to reduce the speckle noise in OCT retinal ...

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    16. Feature Definition and Selection for Epiretinal Membrane Characterization in Optical Coherence Tomography Images

      Feature Definition and Selection for Epiretinal Membrane Characterization in Optical Coherence Tomography Images

      Optical Coherence Tomography (OCT) is a common imaging technique for the detection and analysis of optical diseases, since it is a non invasive method that generates in vivo a cross-sectional visualization of the retinal tissues. These characteristics contributed to the use of OCT imaging in the analysis of pathologies as, for instance, vitreomacular traction, age-related macular degeneration or hypertension. Among its applications, OCT imaging can be used in the detection of any present epiretinal membrane section in the retina, a critical issue to prevent further complications caused by this pathology. This work analyzed the main characteristics of the epiretinal membrane ...

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    17. Choriocapillaris layer imaging with swept-source optical coherence tomography angiography in lamellar and full-thickness macular hole

      Choriocapillaris layer imaging with swept-source optical coherence tomography angiography in lamellar and full-thickness macular hole

      Purpose To present characteristics of choriocapillaris layer imaging with swept-source optical coherence tomography angiography (SS-OCTA) in eyes with macular hole (MH). Methods Patients with MH were included. Vascular density of choriocapillaris (VDC) and central flow void areas were obtained using SS-OCTA. Data were compared with age- and gender-matched normal controls. Results Fifty-one patients with MH and 51 controls were included. Among the 51 patients with MH, 19 had lamellar MH (LMH) and 32 had full-thickness MH (FTMH). While VDC in LMH (79.26 ± 4.06%) was not significantly different from that seen in fellow eyes (79.88 ± 4.28%, P ...

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      Mentions: Korea University
    18. Analysis of choroidal thickness in ocular hypertensive patients using enhanced depth imaging optical coherence tomography

      Analysis of choroidal thickness in ocular hypertensive patients using enhanced depth imaging optical coherence tomography

      This study aimed to compare choroidal thickness between subjects with ocular hypertension (OHT) and normal individuals and explore factors affecting choroidal thickness. This study included 60 untreated newly diagnosed OHT eyes and 60 normal eyes. Choroidal thickness obtained from Cirrus HD-OCT was measured at different locations in the macular and peripapillary regions and compared between the two groups before and after adjusting for potential confounding variables. Regression analysis was performed to figure out factors influencing choroidal thickness. The macular choroidal thickness did not vary significantly between OHT patients and normal controls regardless of locations (all P > 0.05). The average ...

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    19. Classification and characterization of acute macular neuroretinopathy with spectral domain optical coherence tomography

      Classification and characterization of acute macular neuroretinopathy with spectral domain optical coherence tomography

      Purpose To classify and characterize AMN lesions with SD-OCT during a follow-up as long as 5 years. Methods Retrospective study of 14 patients (18 eyes) with special focus on SD-OCT. We measured thickness of inner nuclear layer (INL), outer retinal layer (ONL), and hyperreflective band at baseline and during follow-up. AMN lesions were classified as type 1 and type 2. Results Of 14 patients (six males, eight females, mean age 29.7 years), three patients (four eyes) had type 1 and nine (12 eyes) had type 2. Two patients did not meet the criteria for AMN type 1 or 2 ...

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    20. Atlas of Coronary Intravascular Optical Coherence Tomography (Textbook)

      Atlas of Coronary Intravascular Optical Coherence Tomography (Textbook)

      This atlas is a practical and fully illustrated guide to the use of intravascular OCT in diagnosis and treatment of coronary artery disease. It consists of two parts. The first part of the book provides a systematic introduction to coronary imaging with OCT. It describes how to interpret images and describes abnormal findings seen in atherosclerosis, complications after intervention, and stent assessment. The second part of the book presents real-life case studies that show how OCT is used in clinical practice in Mount Sinai to assess the disease, select appropriate treatment, and evaluate complications and results. Each case includes a ...

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    21. Pearls and pitfalls of optical coherence tomography angiography in the multimodal evaluation of uveitis

      Pearls and pitfalls of optical coherence tomography angiography in the multimodal evaluation of uveitis

      Background Optical coherence tomography angiography (OCTA) employs a novel imaging algorithm that detects the amplitude or phase decorrelation of blood cell movement. It thus provides a flow map with depth-resolved visualization of the various vascular layers in the posterior pole of the eye including the retina capillary plexus and the choroid. In the past 3 years, the number of research papers on the subject of OCTA in retinal diseases has grown exponentially including important applications in the field of uveitis. While the study of OCTA in uveitic diseases has gained remarkable relevance worldwide, interpretation can be challenging, and many limitations ...

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      Mentions: UCLA Vishali Gupta
    22. Quantitative changes in flow density in patients with adult-onset foveomacular vitelliform dystrophy: an OCT angiography study

      Quantitative changes in flow density in patients with adult-onset foveomacular vitelliform dystrophy: an OCT angiography study

      Purpose To quantitatively compare the flow density, the retinal thickness, and the area of the foveal avascular zone (FAZ) between patients with adult-onset foveomacular vitelliform dystrophy (AOFVD) and a healthy controls. Methods Thirteen eyes (eight patients) with AOFVD and 13 matched eyes (13 patients) without any ocular pathology were included in this study. A 6 × 6 mm optical coherence tomography angiography (OCTA) scan was performed for every included eye. The flow density (superficial retinal vascular layer, deep retinal vascular layer and choriocapillary layer), retinal thickness and FAZ (superficial retinal vascular layer and deep retinal vascular layer) were subsequently analyzed. Results ...

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