1. Articles from yueli chen

    1-18 of 18

    1. Polarization memory effect in optical coherence tomography and dental imaging application

      Explore SPIE Digital Library Dentistry
      Polarization memory effect in optical coherence tomography and dental imaging application
      We report the existence of polarization memory effect (PME) in optical coherence tomography and investigate its potential applications in dental imaging. We performed the study in three steps. First, microsphere scattering phantoms of different sizes were imaged in order to validate experimental results with PME theory. Both linearly and circularly polarized light were used to probe the samples. Second, healthy tooth samples were scanned and polarization memory effect was identified in dentin. In this step, specific verification and signal processing were performed to rule out possible image interpretation by birefringence effect. Third, we evaluated dentin demineralization with PME. Results show ...
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      Mentions: University of Maryland University of Connecticut

    2. Documentation of Intraretinal Retinal Pigment Epithelium Migration via High-Speed Ultrahigh-Resolution Optical Coherence Tomography

      Explore Ophthalmology Ophthalmology
      Documentation of Intraretinal Retinal Pigment Epithelium Migration via High-Speed Ultrahigh-Resolution Optical Coherence Tomography

      Purpose: To describe the features of intraretinal retinal pigment epithelium (RPE) migration documented on a prototype spectral-domain, high-speed, ultrahigh-resolution optical coherence tomography (OCT) device in a group of patients with early to intermediate dry age-related macular degeneration (AMD) and to correlate intraretinal RPE migration on OCT to RPE pigment clumping on fundus photographs. Design: Retrospective, noncomparative, noninterventional case series. Participants: Fifty-five eyes of 44 patients seen at the New England Eye Center between December 2007 and June 2008 with early to intermediate dry AMD. Methods: Three-dimensional OCT scan sets from all patients were analyzed for the presence of intraretinal RPE ...

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      Mentions: University of Pittsburgh Massachusetts Institute of Technology Boston University

    3. Clinical Assessment of Mirror Artifacts in Spectral Domain Optical Coherence Tomography

      Explore iovs.org Ophthalmology
      Clinical Assessment of Mirror Artifacts in Spectral Domain Optical Coherence Tomography
      Purpose: To investigate the characteristics of a spectral domain Optical Coherence Tomography (SD OCT) image artifact known as the "mirror artifact", calculate its prevalence, analyze potential risk factors, measure severity, and correlate it to spherical equivalent and central visual acuity (VA). Methods: Cirrus HD-OCT Macular Cube 512x128 scans taken between January 2008 and February 2009 at the New England Eye Center were analyzed for the presence of mirror artifacts. Artifact severity was analyzed by the degree of segmentation breakdown that it causes on the macular map. A retrospective medical records review was conducted for patients with artifacts and for a ...
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      Mentions: University of Pittsburgh Massachusetts Institute of Technology Tufts University

    4. Ultrahigh speed spectral/Fourier domain OCT imaging in ophthalmology

      Explore SPIE Digital Library Ophthalmology
      Ultrahigh speed Spectral/Fourier domain ophthalmic OCT imaging at 70,000-312,500 axial scans per second is demonstrated using a high speed CMOS camera at 800 nm. Comparative imaging results of the fovea illustrate the performance tradeoffs between different imaging speeds and spectrometer configurations. Dense 3D volumetric acquisitions show minimal motion artifacts when acquired at 250,000 axial scans per second. The porous structure of the lamina cribrosa is shown in en face images extracted from a dense volumetric acquisition of the optical nerve head acquired at 106, 382 axial scans per second. Rapid repeated volume imaging (4D-OCT) shows blood ...
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      Mentions: Massachusetts Institute of Technology Thorlabs Tufts University

    5. Assessment of Artifacts and Reproducibility across Spectral- and Time-Domain Optical Coherence Tomography Devices

      Explore OphSource Ophthalmology
      Purpose: To report the frequency of optical coherence tomography (OCT) scan artifacts and to compare macular thickness measurements, interscan reproducibility, and interdevice agreeability across 3 spectral-domain (SD) OCT (also known as Fourier domain; Cirrus HD-OCT, RTVue-100, and Topcon 3D-OCT 1000) devices and 1 time-domain (TD) OCT (Stratus OCT) device.Design: Prospective, noncomparative, noninterventional case series.Participants: Fifty-two patients seen at the New England Eye Center, Tufts Medical Center Retina Service, between February and August 2008.Methods: Two scans were performed for each of the SD OCT protocols: Cirrus macular cube 512×128 (software version 3.0; Carl Zeiss Meditec, Inc ...
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      Mentions: University of Pittsburgh Massachusetts Institute of Technology Visionix

    6. Three-dimensional pointwise comparison of human retinal optical property at 845 and 1060 nm using optical frequency domain imaging

      Explore SPIE Digital Library Ophthalmology

      To compare the optical properties of the human retina, 3-D volumetric images of the same eye are acquired with two nearly identical optical coherence tomography (OCT) systems at center wavelengths of 845 and 1060 nm using optical frequency domain imaging (OFDI). To characterize the contrast of individual tissue layers in the retina at these two wavelengths, the 3-D volumetric data sets are carefully spatially matched. The relative scattering intensities from different layers such as the nerve fiber, photoreceptor, pigment epithelium, and choroid are measured and a quantitative comparison is presented. OCT retinal imaging at 1060 nm is found to have ...

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      Mentions: Massachusetts General Hospital Harvard University

    7. A prototype hybrid intraoperative probe for ovarian cancer detection

      Explore opticsinfobase.org Gynecology , Oncology , Probes
      A prototype hybrid intraoperative probe for ovarian cancer detection
      A novel prototype intraoperative system combining positron detection and optical coherence tomography (OCT) imaging has been developed for early ovarian cancer detection. The probe employs eight plastic scintillating fiber tips for preferential detection of local positron activity surrounding a central scanning OCT fiber providing volumetric imaging of tissue structure in regions of high radiotracer uptake. Characterization measurements of positron sensitivity, spatial response, and position mapping are presented for Tl204/Cs137 sources as well as 18F-FDG. In conjunction with co-registered frequency domain OCT measurements the results demonstrate the potential for a miniaturized laparoscopic probe offering simultaneous functional localization and structural imaging ...
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      Mentions: University of Connecticut

    8. Three-dimensional ultrahigh resolution optical coherence tomography imaging of age-related macular degeneration

      Explore opticsinfobase.org Ophthalmology
      Three-dimensional ultrahigh resolution optical coherence tomography imaging of age-related macular degeneration

      Ultrahigh resolution optical coherence tomography (OCT) enhances the ability to visualize different intra retinal layers. In age-related macular degeneration (AMD), pathological changes in individual retinal layers, including photoreceptor inner and outer segments and retinal pigment ... [Opt. Express 17, 4046-4060 (2009)]

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      Mentions: University of Pittsburgh Massachusetts Institute of Technology Tufts University

    9. Ultrahigh speed spectral/Fourier domain ophthalmic OCT imaging

      Explore SPIE Digital Library Ophthalmology , Tunable Sources
      Ultrahigh speed spectral / Fourier domain optical coherence tomography (OCT) imaging using a CMOS line scan camera with acquisition rates of 70,000 - 312,500 axial scans per second is investigated. Several design configurations are presented to illustrate trade-offs between acquisition speed, sensit ... [Proc. SPIE 7163, 716307 (2009)] published Wed Feb 18, 2009.
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      Mentions: Massachusetts Institute of Technology Thorlabs Tufts University

    10. Ultrahigh-Speed Optical Coherence Tomography for Three-Dimensional and En Face Imaging of the Retina and Optic Nerve Head

      Explore iovs.org Ophthalmology
      Ultrahigh-speed swept-source optical coherence tomography (OCT) imaging of the retina and optic nerve is demonstrated at 249,000 axial scans per second and 1060 nm, while methods for en face visualization of the retina, choroid, and lamina cribrosa are investigated.
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      Mentions: University of Pittsburgh Massachusetts Institute of Technology Tufts University

    11. Ultrahigh speed Spectral / Fourier domain OCT ophthalmic imaging at 70,000 to 312,500 axial scans per second

      Explore opticsinfobase.org Ophthalmology , Tunable Sources
      Ultrahigh speed Spectral / Fourier domain OCT ophthalmic imaging at 70,000 to 312,500 axial scans per second
      We demonstrate ultrahigh speed spectral / Fourier domain optical coherence tomography (OCT) using an ultrahigh speed CMOS line scan camera at rates of 70,000 - 312,500 axial scans per second. Several design configurations are characterized to illustrate trade-offs between acquisition speed, ... [Opt. Express 16, 15149-15169 (2008)]
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      Mentions: Massachusetts Institute of Technology Thorlabs

    12. In Vivo Three-Dimensional Imaging of Neovascular Age-Related Macular Degeneration Using Optical Frequency Domain Imaging at 1050 nm

      Explore iovs.org Ophthalmology , Tunable Sources
      PURPOSE. To assess the application of optical frequency domain imaging (OFDI) at 1050 nm for the detection of choroidal neovascularization (CNV) in age-related macular degeneration (AMD) and its response to treatment. Three patients presenting with blurred vision and exudative AMD were imaged before and after anti-VEGF treatment with ranibizumab. METHODS. The patients were imaged with OFDI, a swept-source–based, high-speed optical coherence tomography (OCT) system developed at the Wellman Center for Photomedicine. A center wavelength of 1050 nm was used that has been demonstrated to provide better imaging of the deeper structures of the retina below the RPE, such as ...
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      Mentions: Massachusetts General Hospital Harvard University Massachusetts Eye and Ear Infirmary

    13. Spectrally balanced detection for optical frequency domain imaging

      Explore opticsinfobase.org Tunable Sources
      In optical frequency domain imaging (OFDI) or swept-source optical coherence tomography, balanced detection is required to suppress relative intensity noise (RIN). A regular implementation of balanced detection by combining reference and sample arm signal in a 50/50 coupler and detecting the ... [Opt. Express 15, 16390-16399 (2007)]
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      Mentions: Massachusetts General Hospital Harvard University

    14. Frequency tracking in optical Doppler tomography using an adaptive notch filter

      Explore SPIE Digital Library
      Optical Doppler tomography is a valuable functional extension of optical coherence tomography (OCT) that can be used to study subsurface blood flows of biological tissues. We propose a novel frequency estimation technique that uses an adaptive notch filter (ANF) to track the depth-resolved Doppler frequency. This new technique is a minimal-parameter filter and works in the time domain without the need of Fourier transformation. Therefore, the algorithm has a computationally efficient structure that may be well suited for implementation in real-time ODT systems. Our simulations and imaging results also demonstrate that this filter has good performance in terms of noise ...
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      Mentions: University of Connecticut

    15. High-speed imaging of human retina in vivo with swept-source optical coherence tomography

      Explore opticsinfobase.org Ophthalmology
      We present the first demonstration of human retinal imaging in vivo using optical frequency domain imaging (OFDI) in the 800-nm range. With 460-μW incident power on the eye, the sensitivity is 91 dB at maximum and >85 dB over 2-mm depth range. The axial resolution is 13 μm in air. We acquired images of retina at 43,200 depth profiles per second and a continuous acquisition speed of 84 frames/s (512 A-lines per frame) could be maintained over more than 2 seconds.
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      Mentions: Massachusetts General Hospital Harvard University

    16. Hybrid positron detection and optical coherence tomography system: design, calibration, and experimental validation with rabbit atherosclerotic models

      Explore SPIE Digital Library Cardiology
      We evaluate the performance of our novel hybrid optical coherence tomography (OCT) and scintillating probe, demonstrate simultaneous OCT imaging and scintillating detection, and validate the system using an atherosclerotic rabbit model. Preliminary data obtained from the rabbit model suggest that our prototype positron probe detects local uptake of fluorodeoxyglucose (FDG) labeled with 18F positron (beta) radionuclide emitter, and the high-uptake regions correlate with sites of injury and extensive atherosclerosis areas. Preliminary data also suggest that coregistered high-resolution OCT images provide imaging of detailed plaque microstructures, which cannot be resolved by positron detection.
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      Mentions: Yale University University of Connecticut

    17. Characterization of dentin, enamel, and carious lesions by a polarization-sensitive optical coherence tomography system

      Explore opticsinfobase.org Dentistry
      Enamel and dentin are the primary components of human teeth. Both of them have a strong polarization effect. We designed a polarization-sensitive optical coherence tomography (PSOCT) system to study the spatially resolved scattering and polarization phenomena of teeth. The system is constructed in free space to avoid the complexity of polarization control in fiber-based PSOCT. The structural features of enamel were evaluated in five human teeth that had no visible evidence of caries. The teeth were subsequently sectioned in mesial distal orientation and coronal orientation. Then the structural aspects of dentin were evaluated. OCT images were made of the mantel ...
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      Mentions: University of Connecticut

    18. Digital signal processor-based real-time optical Doppler tomography system

      Explore SPIE Digital Library
      We present a real-time data-processing and display unit based on a custom-designed digital signal processor (DSP) module for imaging tissue structure and Doppler blood flow. The DSP module is incorporated into a conventional optical coherence tomography system. We also demonstrate the flexibility of embedding advanced Doppler processing algorithms in the DSP module. Two advanced velocity estimation algorithms previously introduced by us are incorporated in this DSP module. Experiments on Intralipid flow demonstrate that a pulsatile flow of several hundred pulses per minute can be faithfully captured in M-scan mode by this DSP system. In vivo imaging of a rat's ...
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      Mentions: University of Connecticut
    1-18 of 18
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    Ultrahigh speed Spectral / Fourier domain OCT ophthalmic imaging at 70,000 to 312,500 axial scans per second Three-dimensional ultrahigh resolution optical coherence tomography imaging of age-related macular degeneration A prototype hybrid intraoperative probe for ovarian cancer detection Clinical Assessment of Mirror Artifacts in Spectral Domain Optical Coherence Tomography Polarization memory effect in optical coherence tomography and dental imaging application Three-dimensional opto-thermo-mechanical model for predicting photo-thermal optical coherence tomography responses in multilayer geometries The role of optical coherence tomography angiography in moderate and advanced primary open-angle glaucoma OCT-angiography follow-up of choroidal neovascularization treated with treat- and- extend aflibercept regimen to avoid over-treatment A Review of Spectroscopic and Non-Spectroscopic Techniques for Diagnosing Breast Cancer Collaboration Between Seno Medical and Cogmedix Drives GOLDEN Results for Innovative Medical Breast Imaging System Prediction of Retinal Ganglion Cell Counts Considering Various Displacement Methods From OCT-Derived Ganglion Cell-Inner Plexiform Layer Thickness Changes of blood flow in macular zone of patients with diabetic retinopathy at different stages evaluated by optical coherence tomography angiography