1. Articles from Sergio Waxman

    1-8 of 8
    1. Plaque burden can be assessed using intravascular optical coherence tomography and a dedicated automated processing algorithm: a comparison study with intravascular ultrasound

      Plaque burden can be assessed using intravascular optical coherence tomography and a dedicated automated processing algorithm: a comparison study with intravascular ultrasound

      Aims Plaque burden (PB) measurement using intravascular optical coherence tomography (IVOCT) is currently thought to be inferior to intravascular ultrasound (IVUS). We developed an automated IVOCT image processing algorithm to enhance the external elastic lamina (EEL) contour. Thus, we investigated the accuracies of standard IVOCT and an IVOCT enhancement algorithm for measuring PB using IVUS as the reference standard. Methods and results The EEL-enhancement algorithm combined adaptive attenuation compensation, exponentiation, angular registration, and image averaging using three sequential frames. In two different laboratories with intravascular imaging expertise, PB was quantified on 200 randomized, matched IVOCT and IVUS images by four ...

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    2. Multi-laboratory inter-institute reproducibility study of IVOCT and IVUS assessments using published consensus document definitions

      Multi-laboratory inter-institute reproducibility study of IVOCT and IVUS assessments using published consensus document definitions

      Aims The aim of this study was to investigate the reproducibility of intravascular optical coherence tomography (IVOCT) assessments, including a comparison to intravascular ultrasound (IVUS). Intra-observer and inter-observer variabilities of IVOCT have been previously described, whereas inter-institute reliability in multiple laboratories has never been systematically studied. Methods and results In 2 independent laboratories with intravascular imaging expertise, 100 randomized matched data sets of IVOCT and IVUS images were analysed by 4 independent observers according to published consensus document definitions. Intra-observer, inter-observer, and inter-institute variabilities of IVOCT qualitative and quantitative measurements vs. IVUS measurements were assessed. Minor inter- and intra-observer variability ...

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    3. Consensus Standards for Acquisition, Measurement, and Reporting of Intravascular Optical Coherence Tomography Studies: A Report From the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation

      Consensus Standards for Acquisition, Measurement, and Reporting of Intravascular Optical Coherence Tomography Studies: A Report From the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation

      Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease.Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of 10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and ...

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    4. An automatic image processing algorithm for initiating and terminating intracoronary OFDI pullback

      An automatic image processing algorithm for initiating and terminating intracoronary OFDI pullback
      Intracoronary optical frequency domain imaging (OFDI) provides high resolution, three-dimensional views of coronary artery microstructure, but requires a non-occlusive saline/contrast purge to displace blood for clear artery views. Recent studies utilized manual pullback initiation/termination based on real-time image observation. Automated pullback initiation/termination by real-time OFDI signal analysis would enable more efficient data acquisition. We evaluate the use of simple imaging parameters to automatically and robustly differentiate between diagnostic-quality clear artery wall (CAW) versus blood-obstructed fields (BOF). Algorithms are tested using intracoronary OCT human data retrospectively and intracoronary OFDI swine and human data prospectively. In prospective analysis of ...
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    5. A Case of Lipid Core Plaque Progression and Rupture at the Edge of a Coronary Stent: Elucidating the Mechanisms of Drug-Eluting Stent Failure

      A Case of Lipid Core Plaque Progression and Rupture at the Edge of a Coronary Stent: Elucidating the Mechanisms of Drug-Eluting Stent Failure
      Understanding the mechanisms of coronary drug-eluting stent (DES) failure remains relevant in light of concerns brought on by clinical reports of life-threatening late and very late stent thrombosis and by autopsy studies showing delayed and incomplete healing inside the stents, which may be related to underlying necrotic lipid core.1 Frequency-domain optical coherence tomography, also known as optical frequency-domain imaging (OFDI), is a new intracoronary imaging technology that enables 3-dimensional visualization of coronary structure in vivo at a resolution (6 µm) sufficient to identify many microscopic features of the coronary wall and stents.2 Here, we present a case of ...
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    6. Performance of reduced bit-depth acquisition for optical frequency domain imaging

      Performance of reduced bit-depth acquisition for optical frequency domain imaging
      High-speed optical frequency domain imaging (OFDI) has enabled practical wide-field microscopic imaging in the biological laboratory and clinical medicine. The imaging speed of OFDI, and therefore the field of view, of current systems is limited by the rate at which data can be digitized and archived rather than the system sensitivity or laser performance. One solution to this bottleneck is to natively digitize OFDI signals at reduced bit depths, e.g., at 8-bit depth rather than the conventional 12-14 bit depth, thereby reducing overall bandwidth. However, the implications of reduced bit-depth acquisition on image quality have not been studied. In ...
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    7. Three-Dimensional Coronary Artery Microscopy by Intracoronary Optical Frequency Domain Imaging

      Three-Dimensional Coronary Artery Microscopy by Intracoronary Optical Frequency Domain Imaging
      Objectives: We present the first clinical experience with intracoronary optical frequency domain imaging (OFDI) in human patients. Background: Intracoronary optical coherence tomography (OCT) is a catheter-based optical imaging modality that is capable of providing microscopic (~7-µm axial resolution, ~30-µm transverse resolution), cross-sectional images of the coronary wall. Although the use of OCT has shown substantial promise for imaging coronary microstructure, blood attenuates the OCT signal, necessitating prolonged, proximal occlusion to screen long arterial segments. OFDI is a second-generation form of OCT that is capable of acquiring images at much higher frame rates. The increased speed of OFDI enables rapid, 3-dimensional ...
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    1-8 of 8
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  2. Topics in the News

    1. (7 articles) Massachusetts General Hospital
    2. (6 articles) Guillermo J. Tearney
    3. (6 articles) Brett E. Bouma
    4. (6 articles) Melissa J. Suter
    5. (5 articles) Harvard University
    6. (5 articles) Sergio Waxman
    7. (4 articles) Milen Shishkov
    8. (3 articles) Cardiovascular Research Foundation
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    Three-Dimensional Coronary Artery Microscopy by Intracoronary Optical Frequency Domain Imaging Performance of reduced bit-depth acquisition for optical frequency domain imaging A Case of Lipid Core Plaque Progression and Rupture at the Edge of a Coronary Stent: Elucidating the Mechanisms of Drug-Eluting Stent Failure An automatic image processing algorithm for initiating and terminating intracoronary OFDI pullback Consensus Standards for Acquisition, Measurement, and Reporting of Intravascular Optical Coherence Tomography Studies: A Report From the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation Multi-laboratory inter-institute reproducibility study of IVOCT and IVUS assessments using published consensus document definitions Multivessel stent thrombosis with Optical Coherence Tomography (OCT) utilization for therapeutic guidance Plaque burden can be assessed using intravascular optical coherence tomography and a dedicated automated processing algorithm: a comparison study with intravascular ultrasound ORCA study: real-world versus reading centre assessment of disease activity of neovascular age-related macular degeneration (nAMD) Role of visual evoked potentials and optical coherence tomography in the screening for optic pathway gliomas in patients with neurofibromatosis type I An assessment of the quality of optical coherence tomography image acquisition Optical coherence tomography evaluation of vertebrobasilar artery stenosis: case series and literature review