1. Extended Coherence Length and Depth Ranging Using a Fourier-Domain Mode-Locked Frequency Comb and Circular Interferometric Ranging

      Extended Coherence Length and Depth Ranging Using a Fourier-Domain Mode-Locked Frequency Comb and Circular Interferometric Ranging
      Fourier-domain mode locking has been a popular laser design for high-speed optical-frequency-domain imaging (OFDI), but achieving long coherence lengths, and therefore imaging range, has been challenging. The narrow linewidth of a Fourier-domain mode-locked (FDML) frequency-comb (FC) laser could provide an attractive platform for high-speed as well as long-range OFDI. Unfortunately, aliasing artifacts arising from signals beyond the principal measurement depth of the free spectral range have prohibited the use of ...
      Read Full Article
    2. Colocalization of neurons in optical coherence microscopy and Nissl-stained histology in Brodmann’s area 32 and area 21

      Colocalization of neurons in optical coherence microscopy and Nissl-stained histology in Brodmann’s area 32 and area 21
      Optical coherence tomography is an optical technique that uses backscattered light to highlight intrinsic structure, and when applied to brain tissue, it can resolve cortical layers and fiber bundles. Optical coherence microscopy (OCM) is higher resolution (i.e., 1.25 m) and is capable of detecting neurons. In a previous report, we compared the correspondence of OCM acquired imaging of neurons with traditional Nissl stained histology in entorhinal cortex layer ...
      Read Full Article
    3. Optic axis mapping with catheter-based polarization-sensitive optical coherence tomography

      Optic axis mapping with catheter-based polarization-sensitive optical coherence tomography
      Birefringence offers an intrinsic contrast mechanism related to the microstructure and arrangement of fibrillary tissue components. Here we present a reconstruction strategy to recover not only the scalar amount of birefringence, but also its optic axis orientation as a function of depth in tissue from measurements with catheter-based polarization-sensitive optical coherence tomography. A polarization symmetry constraint, intrinsic to imaging in the backscatter direction, facilitates the required compensation for wavelength-dependent transmission ...
      Read Full Article
    4. Extended coherence length and depth ranging using a Fourier domain mode-locked frequency comb and circular interferometric ranging

      Extended coherence length and depth ranging using a Fourier domain mode-locked frequency comb and circular interferometric ranging
      Fourier domain mode-locking (FDML) has been a popular laser design for high speed optical frequency domain imaging (OFDI) but achieving long coherence lengths, and therefore imaging range, has been challenging. The narrow instantaneous linewidth of a frequency comb (FC) FDML laser could provide an attractive platform for high speed as well as long range OFDI. Unfortunately, aliasing artifacts arising from signals beyond the principle measurement depth of the free spectral ...
      Read Full Article
    5. Volumetric non-local-means based speckle reduction for optical coherence tomography

      Volumetric non-local-means based speckle reduction for optical coherence tomography
      We present a novel tomographic non-local-means based despeckling technique, TNode, for optical coherence tomography. TNode is built upon a weighting similarity criterion derived for speckle in a three-dimensional similarity window. We present an implementation using a two-dimensional search window, enabling the despeckling of volumes in the presence of motion artifacts, and an implementation using a three-dimensional window with improved performance in motion-free volumes. We show that our technique provides effective ...
      Read Full Article
    6. Robust wavenumber and dispersion calibration for Fourier-domain optical coherence tomography

      Robust wavenumber and dispersion calibration for Fourier-domain optical coherence tomography
      Many Fourier-domain optical coherence tomography (FD-OCT) systems sample the interference fringes with a non-uniform wavenumber ( k ) interval, introducing a chirp to the signal that depends on the path length difference underlying each fringe. A dispersion imbalance between sample and reference arms also generates a chirp in the fringe signal which, in contrast, is independent of depth. Fringe interpolation to obtain a signal linear in k and compensate dispersion imbalance is ...
      Read Full Article
    7. Radiometric model for coaxial single- and multimode optical emission from double-clad fiber

      Radiometric model for coaxial single- and multimode optical emission from double-clad fiber
      Double-clad fibers (DCFs) are versatile waveguides supporting a single-mode core surrounded by a multimode inner cladding. DCFs are increasingly used for multimodal biomedical applications, such as imaging or therapy, for which the core is typically used for coherent illumination and the inner cladding, to support a concurrent modality. Proper optimization is, however, critical to ensure high optical performance and requires accurate modeling of coaxial single- and multimode output beams. In ...
      Read Full Article
    8. Complex differential variance angiography with noise-bias correction for optical coherence tomography of the retina

      Complex differential variance angiography with noise-bias correction for optical coherence tomography of the retina
      Complex differential variance (CDV) provides phase-sensitive angiographic imaging for optical coherence tomography (OCT) with immunity to phase-instabilities of the imaging system and small-scale axial bulk motion. However, like all angiographic methods, measurement noise can result in erroneous indications of blood flow that confuse the interpretation of angiographic images. In this paper, a modified CDV algorithm that corrects for this noise-bias is presented. This is achieved by normalizing the CDV signal ...
      Read Full Article
    9. Clinical Predictors for Lack of Favorable Vascular Response to Statin Therapy in Patients With Coronary Artery Disease: A Serial Optical Coherence Tomography Study

      Clinical Predictors for Lack of Favorable Vascular Response to Statin Therapy in Patients With Coronary Artery Disease: A Serial Optical Coherence Tomography Study
      Background Previous studies have demonstrated that statin therapy improves cardiac outcomes, probably by stabilizing thin‐cap fibroatheroma in patients with coronary artery disease. However, major adverse cardiac events still occur in some patients, despite statin therapy. The aim of this study is to identify clinical predictors for the lack of a favorable vascular response to statin therapy in patients with coronary artery disease. Methods and Results A total of 140 ...
      Read Full Article
    10. Dynamic neointimal pattern after drug-eluting stent implantation defined by optical coherence tomography

      Dynamic neointimal pattern after drug-eluting stent implantation defined by optical coherence tomography
      Objectives: Certain neointimal patterns including neoatherosclerosis (NA) are known to be associated with poor clinical outcome. The prevalence and time course of different neointimal patterns have not been studied systematically. The aim of this study was to investigate the serial changes in neointimal pattern after drug-eluting stent implantation. Patients and methods: A total of 132 patients with 207 drug-eluting stents, who underwent two follow-up optical coherence tomography studies at 6 ...
      Read Full Article
    11. 16  MHz wavelength-swept and wavelength-stepped laser architectures based on stretched-pulse active mode locking with a single continuously chirped fiber Bragg grating

      16  MHz wavelength-swept and wavelength-stepped laser architectures based on stretched-pulse active mode locking with a single continuously chirped fiber Bragg grating
      We demonstrate a novel high-speed and broadband laser architecture based on stretched pulse active mode locking that provides a wavelength-swept and wavelength-stepped output. The laser utilizes a single intracavity 8.3 meter chirped fiber Bragg grating to generate positive and negative dispersion, and can be operated with or without an intracavity fixed FabryPerot etalon to generate wavelength-swept and wavelength-stepped (frequency comb) outputs, respectively. Using a four-path delay line at the ...
      Read Full Article
    12. Beth Isreal Deaconess Medical Center Receives Grant for Intravascular Molecular-Structural Imaging of Coronary Stent Pathobiology

      Beth Isreal Deaconess Medical Center Receives Grant for Intravascular Molecular-Structural Imaging of Coronary Stent Pathobiology
      ...rly career faculty member at Beth Israel Deaconess Medical Center (BIDMC) and Massachusetts General Hospital (MGH), and an Instructor in Medicine at Harvard Medical School, Boston, Massachusetts. He is a graduate of the ...
      Read Full Article
    13. In vivo label-free measurement of lymph flow velocity and volumetric flow rates using Doppler optical coherence tomography

      In vivo label-free measurement of lymph flow velocity and volumetric flow rates using Doppler optical coherence tomography
      Direct in vivo imaging of lymph flow is key to understanding lymphatic system function in normal and disease states. Optical microscopy techniques provide the resolution required for these measurements, but existing optical techniques for measuring lymph flow require complex protocols and provide limited temporal resolution. Here, we describe a Doppler optical coherence tomography platform that allows direct, label-free quantification of lymph velocity and volumetric flow rates. We overcome the challenge ...
      Read Full Article
    14. An Elastic Second Skin

      An Elastic Second Skin
      We report the synthesis and application of an elastic, wearable crosslinked polymer layer (XPL) that mimics the properties of normal, youthful skin. XPL is made of a tunable polysiloxane-based material that can be engineered with specific elasticity, contractility, adhesion, tensile strength and occlusivity. XPL can be topically applied, rapidly curing at the skin interface without the need for heat- or light-mediated activation. In a pilot human study, we examined the ...
      Read Full Article
    15. Three-dimensional morphological response of lipid-rich coronary plaques to statin therapy: a serial optical coherence tomography study

      Three-dimensional morphological response of lipid-rich coronary plaques to statin therapy: a serial optical coherence tomography study
      Objective: Previous studies have suggested that intensive statin therapy, compared with moderate statin therapy, provided greater reduction of LDL and better protection against major cardiovascular events. However, the exact dose-dependent mechanism of plaque stabilization remains unclear. The aim of this study is to investigate the three-dimensional (3D) response of fibrous caps overlying lipid plaques to statin therapy. Methods: We applied a novel computer algorithm to investigate the fibrous cap 3D ...
      Read Full Article
    16. Intravascular fibrin molecular imaging improves the detection of unhealed stents assessed by optical coherence tomography in vivo

      Intravascular fibrin molecular imaging improves the detection of unhealed stents assessed by optical coherence tomography in vivo
      Aims Fibrin deposition and absent endothelium characterize unhealed stents that are at heightened risk of stent thrombosis. Optical coherence tomography (OCT) is increasingly used for assessing stent tissue coverage as a measure of healed stents, but cannot precisely identify whether overlying tissue represents physiological neointima. Here we assessed and compared fibrin deposition and persistence on bare metal stent (BMS) and drug-eluting stent (DES) using near-infrared fluorescence (NIRF) molecular imaging in ...
      Read Full Article
    17. Quantitative analysis of the side-branch orifice after bifurcation stenting using en-face processing of OCT images: a comparison between Xience V and Resolute Integrity stents

      Quantitative analysis of the side-branch orifice after bifurcation stenting using en-face processing of OCT images: a comparison between Xience V and Resolute Integrity stents
      Objective: Methods for intravascular assessment of the side-branch (SB) orifice after stenting are not readily available. The aim of this study was to assess the utility of an en-face projection processing for optical coherence tomography (OCT) images for SB evaluation. Methods: Measurements of the SB orifice obtained using en-face OCT images were validated using a phantom model. Linear regression modeling was applied to estimated area measurements made on the en-face ...
      Read Full Article
    18. Impacts of lesion angle on incidence and distribution of acute vessel wall injuries and strut malapposition after drug-eluting stent implantation assessed by optical coherence tomography

      Impacts of lesion angle on incidence and distribution of acute vessel wall injuries and strut malapposition after drug-eluting stent implantation assessed by optical coherence tomography
      Aims To investigate the impact of lesion angle on the incidence and distribution of acute vessel wall injuries and incomplete stent apposition (ISA) following second-generation drug-eluting stent (DES) implantation using optical coherence tomography (OCT). Several ex vivo studies demonstrated that angled arterial walls are exposed to imbalanced mechanical stress from deployed stents. Methods and results We included 243 lesions treated with a single DES (148 everolimus-eluting stent and 95 zotarolimus-eluting ...
      Read Full Article
    19. Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler

      Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler
      ... ^3School of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon, South Korea ^4Harvard-Massachusetts Institute of Technology, Program in Health Sciences and Technology, Cambridge, Massachusetts 021...
      Read Full Article
    20. Optical coherence tomography visualizes neurons in human entorhinal cortex

      Optical coherence tomography visualizes neurons in human entorhinal cortex
      The cytoarchitecture of the human brain is of great interest in diverse fields: neuroanatomy, neurology, neuroscience, and neuropathology. Traditional histology is a method that has been historically used to assess cell and fiber content in the ex vivo human brain. However, this technique suffers from significant distortions. We used a previously demonstrated optical coherence microscopy technique to image individual neurons in several square millimeters of en-face tissue blocks from layer ...
      Read Full Article
    21. Dual modality intravascular optical coherence tomography (OCT) and near-infrared fluorescence (NIRF) imaging: a fully automated algorithm for the distance-calibration of NIRF signal intensity for quantitative molecular imaging

      Dual modality intravascular optical coherence tomography (OCT) and near-infrared fluorescence (NIRF) imaging: a fully automated algorithm for the distance-calibration of NIRF signal intensity for quantitative molecular imaging
      ...al intensity for quantitative molecular imaging Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, MA, USA Cardiovascular Research Center and Cardiology Division, Harva...
      Read Full Article
    22. 1-24 of 84 1 2 3 4 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Organizations in the News

    1. (63 articles) Harvard University
    2. (8 articles) Massachusetts General Hospital OCT Registry
    3. (7 articles) UC Irvine
    4. (6 articles) Boston University
    5. (5 articles) University of Illinois at Urbana-Champaign
    6. (5 articles) Harbin Medical University
    7. (5 articles) National Institutes of Health
    8. (4 articles) Korea Advanced Institute of Science and Technology
    9. (4 articles) FDA
    10. (4 articles) Brigham and Women’s Hospital
    11. (4 articles) Duke University
    12. (4 articles) University of Pittsburgh
  3. People in the News

    1. (29 articles) Brett E. Bouma
    2. (29 articles) James G. Fujimoto
    3. (19 articles) Guillermo J. Tearney
    4. (13 articles) Ik-Kyung Jang
    5. (10 articles) Benjamin J. Vakoc
    6. (9 articles) David A. Boas
    7. (9 articles) Aaron D. Aguirre
    8. (8 articles) Zhao Wang
    9. (8 articles) Hang Lee
    10. (7 articles) Martin L. Villiger
    11. (7 articles) Eric A. Swanson
    12. (6 articles) Stephen A. Boppart
  4. OCT Companies in the News

    1. (7 articles) St. Jude Medical
    2. (6 articles) Thorlabs
    3. (6 articles) NinePoint Medical
    4. (4 articles) Carl Zeiss Meditec
    5. (3 articles) Terumo Corporation
    6. (3 articles) Imalux
    7. (2 articles) Lantis Laser
    8. (2 articles) Volcano Corporation
    9. (2 articles) Tomophase Corporation
    10. (2 articles) D4D Technologies
    11. (2 articles) Heliotis AG
    12. (2 articles) Bioptigen