1. Articles from Jun Cheng

    1-18 of 18
    1. Speckle reduction of OCT via super resolution reconstruction and its application on retinal layer segmentation

      Speckle reduction of OCT via super resolution reconstruction and its application on retinal layer segmentation

      Optical coherence tomography (OCT) is a rapidly developing non-invasive three dimensional imaging approach, and it has been widely used in examination and diagnosis of eye diseases. However, speckle noise are often inherited from image acquisition process, and may obscure the anatomical structure, such as the retinal layers. In this paper, we propose a novel method to reduce the speckle noise in 3D OCT scans, by introducing a new super-resolution approach. It uses a multi-frame fusion mechanism that merges multiple scans for the same scene, and utilizes the movements of sub-pixels to recover missing signals in one pixel, which significantly improves ...

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    2. BIONET: INFUSING BIOMARKER PRIOR INTO GLOBAL-TO-LOCAL NETWORK FOR CHOROID SEGMENTATION IN OPTICAL COHERENCE TOMOGRAPHY IMAGES

      BIONET: INFUSING BIOMARKER PRIOR INTO GLOBAL-TO-LOCAL NETWORK FOR CHOROID SEGMENTATION IN OPTICAL COHERENCE TOMOGRAPHY IMAGES

      Choroid is the vascular layer of the eye, which is directly related to the incidence and severity of many ocular diseases. Optical Coherence Tomography (OCT) is capable of imaging both the cross-sectional view of retina and choroid, but the segmentation of the choroid region is challenging because of the fuzzy choroid-sclera interface (CSI). In this paper, we propose a biomarker infused global-to-local network (BioNet) for choroid segmentation, which segments the choroid with higher credibility and robustness. Firstly, our method trains a biomarker prediction network to learn the features of the biomarker. Then a global multi-layers segmentation module is applied to ...

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    3. Speckle reduction in optical coherence tomography images

      Speckle reduction in optical coherence tomography images

      An optical coherence tomography (OCT) image composed of a plurality of A-scans of a structure is analyzed by defining, for each A-scan, a set of neighboring A-scans surrounding the A-slices scan. Following an optional de-noising step, the neighboring A-scans are aligned in the imaging direction, then a matrix X is formed from the aligned A-scans, and matrix completion is performed to obtain a reduced speckle noise image.

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    4. Automatic fibroatheroma identification in intravascular optical coherence tomography volumes

      Automatic fibroatheroma identification in intravascular optical coherence tomography volumes

      Coronary heart disease is the most common type of heart disease that leads to heart attacks. The identification of vulnerable plaques, especially the thin-cap fibroatheroma (TCFA), is crucial to the diagnosis of coronary artery disease. Intravascular optical coherence tomography (IVOCT), an emerging imaging modality, has been proven to be useful for the identification of vulnerable plaques. In this work, we propose an approach to identify the volumes with fibroatheroma frames automatically. In the proposed method, we first detect the lumen using a graph-search based method from unfolded images. Then a region of interest starting from the lumen boundary is cropped ...

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    5. Optical coherence tomography angiography of the macula and optic nerve head: microvascular density and test-retest repeatability in normal subjects

      Optical coherence tomography angiography of the macula and optic nerve head: microvascular density and test-retest repeatability in normal subjects

      Background Despite the potential usefulness of optical coherence tomography angiography in retinal and optic disc conditions, the reliability of the imaging modality remains unclear. This study set out to measure the microvascular density of macula and optic disc by mean of optical coherence tomography angiography and report the repeatability of the vessel density measurements. Methods Cross sectional observational cohort study. Subjects with normal eyes were recruited. Two sets of optical coherence tomography angiography images of macula and optic nerve head were acquired during one visit. Novel in-house developed software was used to count the pixels in each images and to ...

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    6. Reducing speckle noise in optical coherence tomography images

      Reducing speckle noise in optical coherence tomography images

      A method and system are proposed to obtain a reduced speckle noise image of a subject from optical coherence tomography (OCT) image data of the subject. The cross sectional images each comprise a plurality of scan lines obtained by measuring the time delay of light reflected, in a depth direction, from optical interfaces within the subject. The method comprises two aligning steps. First the cross sectional images are aligned, then image patches of the aligned cross sectional images are aligned to form a set of aligned patches. An image matrix is then formed from the aligned patches; and matrix completion ...

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    7. Optical Coherence Tomography Angiography of Optic Disc and Macula Vessel Density in Glaucoma and Healthy Eyes

      Optical Coherence Tomography Angiography of Optic Disc and Macula Vessel Density in Glaucoma and Healthy Eyes

      Aim: To study the microvascular density of the macular and optic nerve head in healthy and glaucoma subjects using optical coherence tomography angiography . Methodology: We performed a cross-sectional cohort study on healthy subjects and patients with glaucoma . The AngioVue Enhanced Microvascular Imaging System was used to capture the optic nerve head and macula images during one visit. En face segment images of the macular and optic disc were studied in layers. Microvascular density of the optic nerve head and macula were quantified by the number of pixels measured by a novel in-house developed software. Areas under the receiver operating characteristic ...

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    8. Three-dimensional graph-based skin layer segmentation in optical coherence tomography images for roughness estimation

      Three-dimensional graph-based skin layer segmentation in optical coherence tomography images for roughness estimation

      Automatic skin layer segmentation in optical coherence tomography (OCT) images is important for a topographic assessment of skin or skin disease detection. However, existing methods cannot deal with the problem of shadowing in OCT images due to the presence of hair, scales, etc. In this work, we propose a method to segment the topmost layer of the skin (or the skin surface) using 3D graphs with a novel cost function to deal with shadowing in OCT images. 3D graph cuts use context information across B-scans when segmenting the skin surface, which improves the segmentation as compared to segmenting each B-scan ...

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    9. Automatic Fibroatheroma Identification from Intravascular Optical Coherence Tomography Images

      Automatic Fibroatheroma Identification from Intravascular Optical Coherence Tomography Images

      Vulnerable plaque identification is important in coronary heart disease diagnosis. Intravascular Optical Coherence Tomography (IVOCT) is an imaging modality which can characterize the appearance of vulnerable plaques. However, current used manual reading of the images is time consuming and subjective. Therefore, an automated and objective assessment of the plaque is necessary. This paper proposes a method for automatic identification of potential vulnerable plaque such as fibroatheroma in IVOCT images. In the proposed method, a graph search based method is applied to detect the region of interest (ROI) including the inner lumen border and outer border. Then various appearance features including ...

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    10. Motion Correction in Optical Coherence Tomography for Multi-modality Retinal Image Registration

      Motion Correction in Optical Coherence Tomography for Multi-modality Retinal Image Registration

      Optical coherence tomography (OCT) is a recently developed non-invasive imaging modality, which is often used in ophthalmology. Because of the sequential scanning in form of A-scans, OCT suffers from the inevitable eye movement. This often leads to mis-alignment especially among consecutive B-scans, which affects the analysis and processing of the data such as the registration of the OCT en face image to color fundus image. In this paper, we propose a novel method to correct the mis-alignment among consecutive B-scans to improve the accuracy in multi-modality retinal image registration. In the method, we propose to compute decorrelation from overlapping B-scans ...

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    11. Speckle Reduction in 3D Optical Coherence Tomography of Retina by A-Scan Reconstruction

      Speckle Reduction in 3D Optical Coherence Tomography of Retina by A-Scan Reconstruction

      Optical coherence tomography (OCT) is a micrometer-scale, cross-sectional imaging modality for biological tissue. It has been widely used for retinal imaging in ophthalmology. Speckle noise is problematic in OCT. A raw OCT image/volume usually has very poor image quality due to speckle noise, which often obscures the retinal structures. Overlapping scan is often used for speckle reduction in a 2D line-scan. However, it leads to an increase of the data acquisition time. Therefore, it is unpractical in 3D scan as it requires a much longer data acquisition time. In this paper, we propose a new method for speckle reduction ...

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    12. Corneal graft evaluation based on optical coherence tomography image

      Corneal graft evaluation based on optical coherence tomography image

      An OCT image of an eye which has been subject to a DSAEK corneal transplant, in which a Descement's membrane in the cornea has been replaced by a graft, is processed to identify the outline of the graft. The process includes the steps of: computationally extracting the boundary of the cornea including the graft; computationally detecting the corners of the graft; computationally extracting points on the boundary between the graft and the original cornea; and computationally fitting the points on the boundary between the graft and the original cornea smoothly into a curve. The outline of the graft is ...

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    13. Speckle reduction in optical coherence tomography by matrix completion using bilateral random projection

      Speckle reduction in optical coherence tomography by matrix completion using bilateral random projection

      Speckle noise is problematic in optical coherence tomography (OCT) and often obscures the structure details. In this paper, we propose a new method to reduce speckle noise from multiply scanned OCT slices. The proposed method registers the OCT scans using a global alignment followed by a local alignment based on global and local motion estimation. Then low rank matrix completion using bilateral random projection is utilized to estimate the noise and recover the clean image. Experimental results show that the proposed method archives average contrast to noise ratio 14.90, better than 13.78 by the state-of-the-art method used in ...

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    14. Automatic atherosclerotic heart disease detection in intracoronary optical coherence tomography images

      Automatic atherosclerotic heart disease detection in intracoronary optical coherence tomography images

      Intracoronary optical coherence tomography (OCT) is a new invasive imaging system which produces highresolution images of coronary arteries. Preliminary data suggests that the atherosclerotic disease can be detected from the intracoronary OCT images. However, manual assessment of the intracoronary OCT images is time-consuming and subjective. In this work, we present an automatic atherosclerotic disease detection system on intracoronary OCT images. In the system, a preprocessing scheme is first applied to remove speckle noise and artifacts caused by catheter. Intensity, Histograms of Oriented Gradients (HOG), and Local Binary Patterns (LBP) are then extracted to represent the OCT image. Finally a linear ...

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    15. Speckle Reduction in Optical Coherence Tomography by Image Registration and Matrix Completion

      Speckle Reduction in Optical Coherence Tomography by Image Registration and Matrix Completion

      Speckle noise is problematic in optical coherence tomography (OCT). With the fast scan rate, swept source OCT scans the same position in the retina for multiple times rapidly and computes an average image from the multiple scans for speckle reduction. However, the eye movement poses some challenges. In this paper, we propose a new method for speckle reduction from multiply-scanned OCT slices. The proposed method applies a preliminary speckle reduction on the OCT slices and then registers them using a global alignment followed by a local alignment based on fast iterative diamond search. After that, low rank matrix completion using ...

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    16. Automated anterior chamber angle localization and glaucoma type classification in OCT images

      Automated anterior chamber angle localization and glaucoma type classification in OCT images

      To identify glaucoma type with OCT (optical coherence tomography) images, we present an image processing and machine learning based framework to localize and classify anterior chamber angle (ACA) accurately and efficiently. In digital OCT photographs, our method automatically localizes the ACA region, which is the primary structural image cue for clinically identifying glaucoma type. Next, visual features are extracted from this region to classify the angle as open angle (OA) or angle-closure (AC). This proposed method has three major contributions that differ from existing methods. First, the ACA localization from OCT images is fully automated and efficient for different ACA ...

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    17. Corneal Graft Evaluation Based On Optical Coherence Tomography Image

      Corneal Graft Evaluation Based On Optical Coherence Tomography Image

      An OCT image of an eye which has been subject to a DSAEK corneal transplant, in which a Descement's membrane in the cornea has been replaced by a graft, is processed to identify the outline of the graft. The process includes the steps of: computationally extracting the boundary of the cornea including the graft; computationally detecting the corners of the graft; computationally extracting points on the boundary between the graft and the original cornea; and computationally fitting the points on the boundary between the graft and the original cornea smoothly into a curve. The outline of the graft is ...

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    18. Corneal graft detection for Descemet's Stripping Automated Endothelial Keratoplasty using Optical Coherence Tomography

      Corneal graft detection for Descemet's Stripping Automated Endothelial Keratoplasty using Optical Coherence Tomography

      The cornea is the window of the eye and when it is severely damaged or diseased, vision is impaired. Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) is a surgical procedure to replace the malfunctioned Descemet's membrane with a healthy one in order to restore the patient's sight. After the operation, ophthalmologists need to monitor the grafted membrane to check for signs of detachment, rejection, etc. and take appropriate actions before graft failure occurs. In this paper, we introduce the COrneaL GrAft Thickness Evaluation (COLGATE) System that we developed for ophthalmologists for the evaluation of the transplanted corneal graft ...

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    1-18 of 18
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    1. (5 articles) Chinese Academy of Sciences
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    Corneal graft detection for Descemet's Stripping Automated Endothelial Keratoplasty using Optical Coherence Tomography Corneal Graft Evaluation Based On Optical Coherence Tomography Image Automated anterior chamber angle localization and glaucoma type classification in OCT images Speckle Reduction in Optical Coherence Tomography by Image Registration and Matrix Completion Automatic atherosclerotic heart disease detection in intracoronary optical coherence tomography images Speckle reduction in optical coherence tomography by matrix completion using bilateral random projection Corneal graft evaluation based on optical coherence tomography image Speckle Reduction in 3D Optical Coherence Tomography of Retina by A-Scan Reconstruction Automatic Fibroatheroma Identification from Intravascular Optical Coherence Tomography Images Three-dimensional graph-based skin layer segmentation in optical coherence tomography images for roughness estimation Structural abnormalities associated with glaucoma using swept-source optical coherence tomography in patients with systemic sclerosis Clinical presentation does not affect acute mechanical performance of the Novolimus-eluting bioresorbable vascular scaffold as assessed by optical coherence tomography