1. Articles mentioning both Harvard University and Massachusetts Institute of Technology

    1-24 of 139 1 2 3 4 5 6 »
    1. Light-sheet photonic force optical coherence elastography for high-throughput quantitative 3D micromechanical imaging

      Light-sheet photonic force optical coherence elastography for high-throughput quantitative 3D micromechanical imaging
      Quantitative characterisation of micro-scale mechanical properties of the extracellular matrix (ECM) and dynamic cell-ECM interactions can significantly enhance fundamental discoveries and their translational potential in the rapidly growing field of mechanobiology. However, quantitative 3D imaging of ECM mechanics with cellular-scale resolution and dynamic monitoring of cell-mediated changes to pericellular viscoelasticity remain a challenge for existing mechanical characterisation methods. Here, we present light-sheet photonic force optical coherence elastography (LS-pfOCE) to address ...
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    2. A novel algorithm for multiplicative speckle noise reduction in ex vivo human brain OCT images

      A novel algorithm for multiplicative speckle noise reduction in ex vivo human brain OCT images
      Optical coherence tomography (OCT) images of ex vivo human brain tissue are corrupted by multiplicative speckle noise that degrades the contrast to noise ratio (CNR) of microstructural compartments. This work proposes a novel algorithm to reduce noise corruption in OCT images that minimizes the penalized negative log likelihood of gamma distributed speckle noise. The proposed method is formulated as a majorize-minimize problem that reduces to solving an iterative regularized least ...
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    3. Ultrahigh resolution spectral-domain optical coherence tomography using the 1000-1600 nm spectral band

      Ultrahigh resolution spectral-domain optical coherence tomography using the 1000-1600 nm spectral band
      Ultrahigh resolution optical coherence tomography (UHR-OCT) can image microscopic features that are not visible with the standard OCT resolution of 5-15 m. In previous studies, high-speed UHR-OCT has been accomplished within the visible (VIS) and near-infrared (NIR-I) spectral ranges, specifically within 550-950 nm. Here, we present a spectral domain UHR-OCT system operating in a short-wavelength infrared (SWIR) range from 1000 to 1600 nm using a supercontinuum light source and an ...
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    4. Optical coherence tomography in coronary atherosclerosis assessment and intervention

      Optical coherence tomography in coronary atherosclerosis assessment and intervention
      Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in ...
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    5. Relationship between axial resolution and signal-to-noise ratio in optical coherence tomography

      Relationship between axial resolution and signal-to-noise ratio in optical coherence tomography
      In optical coherence tomography (OCT), axial resolution and signal-to-noise ratio (SNR) are typically viewed as uncoupled parameters. We show that this is true only for mirror-like surfaces and that in diffuse scattering samples such as biological tissues there is an inherent coupling between axial resolution and measurement SNR. We explain the origin of this coupling and demonstrate that it can be used to achieve increased imaging penetration depth at the ...
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    6. Impact and implications of mixed plaque class in automated characterization of complex atherosclerotic lesions

      Impact and implications of mixed plaque class in automated characterization of complex atherosclerotic lesions
      Atherosclerosis is a complex disease altering vasculature morphology, and subsequently flow, with progressive plaque formation, mural disruption, and lumen occlusion. Determination of clinically-relevant plaque componentsparticularly calcium, lipid, and fibrous tissuehas driven automated image-based tissue characterization. Atherosclerotic tissue of mixed composition type arises when these principal components interdigitate and combine during the course of progressive atherosclerosis. Nevertheless, such mixed plaque is treated non-uniformly, and often neglected, as a distinct class in ...
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    7. Is Real-Time Microscopy on the Horizon? A Brief Review of the Potential Future Directions in Clinical Breast Tumor Microscopy Implementation

      Is Real-Time Microscopy on the Horizon? A Brief Review of the Potential Future Directions in Clinical Breast Tumor Microscopy Implementation
      We will briefly review the current paradigm and some recent developments in the area of clinical breast microscopy, highlighting several promising commercially available, and research-based platforms. Confocal microscopy (reflectance, fluorescence, and spectrally encoded), optical coherence tomography (wide field and full field), stereomicroscopy, open-top light sheet microscopy, microscopy with ultraviolet surface excitation, nonlinear microscopy, Raman scattering microscopy, photoacoustic microscopy, and needle microendoscopy will be discussed. Non-microscopic methods for breast pathology assessment ...
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    8. Refractive-index matching enhanced polarization sensitive optical coherence tomography quantification in human brain tissue

      Refractive-index matching enhanced polarization sensitive optical coherence tomography quantification in human brain tissue
      The importance of polarization-sensitive optical coherence tomography (PS-OCT) has been increasingly recognized in human brain imaging. Despite the recent progress of PS-OCT in revealing white matter architecture and orientation, quantification of fine-scale fiber tracts in the human brain cortex has been a challenging problem, due to a low birefringence in the gray matter. In this study, we investigated the effect of refractive index matching by 2,2-thiodiethanol (TDE) immersion on ...
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    9. An inverse method for mechanical characterization of heterogeneous diseased arteries using intravascular imaging

      An inverse method for mechanical characterization of heterogeneous diseased arteries using intravascular imaging
      The increasing prevalence of finite element (FE) simulations in the study of atherosclerosis has spawned numerous inverse FE methods for the mechanical characterization of diseased tissue in vivo. Current approaches are however limited to either homogenized or simplified material representations. This paper presents a novel method to account for tissue heterogeneity and material nonlinearity in the recovery of constitutive behavior using imaging data acquired at differing intravascular pressures by incorporating ...
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    10. A platform for high-fidelity patient-specific structural modelling of atherosclerotic arteries: from intravascular imaging to three-dimensional stress distributions

      A platform for high-fidelity patient-specific structural modelling of atherosclerotic arteries: from intravascular imaging to three-dimensional stress distributions
      The pathophysiology of atherosclerotic lesions, including plaque rupture triggered by mechanical failure of the vessel wall, depends directly on the plaque morphology-modulated mechanical response. The complex interplay between lesion morphology and structural behaviour can be studied with high-fidelity computational modelling. However, construction of three-dimensional (3D) and heterogeneous models is challenging, with most previous work focusing on two-dimensional geometries or on single-material lesion compositions. Addressing these limitations, we here present a ...
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    11. Quantification of volumetric morphometry and optical property in the cortex of human cerebellum at micrometer resolution

      Quantification of volumetric morphometry and optical property in the cortex of human cerebellum at micrometer resolution
      The surface of the human cerebellar cortex is much more tightly folded than the cerebral cortex. Volumetric analysis of cerebellar morphometry in magnetic resonance imaging studies suffers from insufficient resolution, and therefore has had limited impact on disease assessment. Automatic serial polarization-sensitive optical coherence tomography (as-PSOCT) is an emerging technique that offers the advantages of microscopic resolution and volumetric reconstruction of large-scale samples. In this study, we reconstructed multiple cubic ...
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    12. Refractive-index matching enhanced polarization-sensitive optical coherence tomography quantification in human brain tissue

      Refractive-index matching enhanced polarization-sensitive optical coherence tomography quantification in human brain tissue
      The importance of polarization-sensitive optical coherence tomography (PS-OCT) has been increasingly recognized in human brain imaging. Despite the recent progress of PS-OCT in revealing white matter architecture and orientation, quantification of fine-scale fiber tracts in the human brain cortex has been a challenging problem, due to a low birefringence in the gray matter. In this study, we investigated the effect of refractive index matching by 2,2'-thiodiethanol (TDE) immersion ...
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    13. Layer-based, depth-resolved computation of attenuation coefficients and backscattering fractions in tissue using optical coherence tomography

      Layer-based, depth-resolved computation of attenuation coefficients and backscattering fractions in tissue using optical coherence tomography
      Structural optical coherence tomography (OCT) images of tissue stand to benefit from greater functionalization and quantitative interpretation. The OCT attenuation coefficient , an analogue of the imaged samples scattering coefficient, offers potential functional contrast based on the relationship of to sub-resolution physical properties of the sample. Attenuation coefficients are computed either by fitting a representative over several depth-wise pixels of a samples intensity decay, or by using previously-developed depth-resolved attenuation algorithms ...
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    14. Correction of circumferential and longitudinal motion distortion in high-speed catheter/endoscope-based optical coherence tomography

      Correction of circumferential and longitudinal motion distortion in high-speed catheter/endoscope-based optical coherence tomography
      ... performed under an IRB protocol approved by VA Boston Healthcare System (VABHS), Harvard Medical School, and Massachusetts Institute of Technology. Written informed consent was obtained before imaging. Data was obtained...
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    15. Historic Effort to 'End Blindness" Marks a Major Milestone with Leading Scientist Recognized for Pioneering Work at VIP Ceremony Featuring Tribute To Ruth Bader Ginsburg

      Historic Effort to 'End Blindness" Marks a Major Milestone with Leading Scientist Recognized for Pioneering Work at VIP Ceremony Featuring Tribute To Ruth Bader Ginsburg
      ...r him. Over the following years, Dr. Greenberg went on to achieve extraordinary success, earning an PhD from Harvard, becoming a White House Fellow in the Johnson Administration, and innovating important new technologie...
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    16. Linear-in-wavenumber actively-mode-locked wavelength-swept laser

      Linear-in-wavenumber actively-mode-locked wavelength-swept laser
      We report on an akinetic actively-mode-locked wavelength-swept laser (ASL) with a sweep that is highly linear in wavenumber. By tailoring the drive waveform of the intracavity modulator, the wavenumber sweep was further linearized to enable high fidelity frequency-domain interferometric ranging without resampling of the acquired data. Used for catheter-based optical coherence tomography, the ASL showed comparable imaging performance to a state-of-the-art polygon-based wavelength-swept source at a matching sweep rate of ...
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    17. Imaging intracellular motion with dynamic micro-optical coherence tomography

      Imaging intracellular motion with dynamic micro-optical coherence tomography
      This paper describes a new technology that uses 1-m-resolution optical coherence tomography (OCT) to obtain cross-sectional images of intracellular dynamics with dramatically enhanced image contrast. This so-called dynamic OCT (d-OCT) is accomplished by acquiring a time series of OCT images and conducting power frequency analysis of the temporal fluctuations that arise from intracellular motion on a pixel-per-pixel basis. Here, we demonstrate d-OCT imaging of freshly excised human esophageal and cervical ...
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    18. Noise and bias in optical coherence tomography intensity signal decorrelation

      Noise and bias in optical coherence tomography intensity signal decorrelation
      Functional optical coherence tomography (OCT) imaging based on the decorrelation of the intensity signal has been used extensively in angiography and is finding use in flowmetry and therapy monitoring. In this work, we present a rigorous analysis of the autocorrelation function, introduce the concepts of contrast bias, statistical bias and variability, and identify the optimal definition of the second-order autocorrelation function (ACF) g (2) to improve its estimation from limited ...
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    19. Forward multiple scattering dominates speckle decorrelation in whole-blood flowmetry using optical coherence tomography

      Forward multiple scattering dominates speckle decorrelation in whole-blood flowmetry using optical coherence tomography
      Quantitative blood flow measurements using optical coherence tomography (OCT) have a wide potential range of medical research and clinical applications. Flowmetry based on the temporal dynamics of the OCT signal may have the ability to measure three-dimensional flow profiles regardless of the flow direction. State-of-the-art models describing the OCT signal temporal statistics are based on dynamic light scattering (DLS), a model which is inherently limited to single scattering regimes. DLS ...
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    20. Beth Israel Deaconess Medical Center Receives NIH Grant for Intravascular Molecular-Structural Imaging of Coronary Stent Pathobiology

      Beth Israel Deaconess Medical Center Receives NIH Grant for Intravascular Molecular-Structural Imaging of Coronary Stent Pathobiology
      ...uctor in Medicine at Harvard Medical School, Boston, Massachusetts. He is a graduate of the MD-PhD program at Harvard Medical School and Massachusetts Institute of Technology, and has completed clinical training in medic...
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    21. Intravascular Polarimetry in Patients With Coronary Artery Disease

      Intravascular Polarimetry in Patients With Coronary Artery Disease
      Objectives The aims of this first-in-human pilot study of intravascular polarimetry were to investigate polarization properties of coronary plaques in patients and to examine the relationship of these features with established structural characteristics available to conventional optical frequency domain imaging (OFDI) and with clinical presentation. Background Polarization-sensitive OFDI measures birefringence and depolarization of tissue together with conventional cross-sectional optical frequency domain images of subsurface microstructure. Methods Thirty patients undergoing polarization-sensitive ...
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    22. Healed Culprit Plaques in Patients With Acute Coronary Syndrome

      Healed Culprit Plaques in Patients With Acute Coronary Syndrome
      ackground Healed plaques, morphologically characterized by a layered phenotype, are frequently found in subjects with sudden cardiac death. However, in vivo data are lacking. Objectives The purpose of this study was to determine the prevalence, morphological characteristics, and clinical significance of healed culprit plaques in patients with acute coronary syndromes (ACS) using optical coherence tomography (OCT). Methods A total of 376 ACS patients (252 ST-segment elevation myocardial infarction [MI] and ...
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    23. Balloon catheter-based radiofrequency ablation monitoring in porcine esophagus using optical coherence tomography

      Balloon catheter-based radiofrequency ablation monitoring in porcine esophagus using optical coherence tomography
      We present a microscopic image guidance platform for radiofrequency ablation (RFA) using a clinical balloon-catheter-based optical coherence tomography (OCT) system, currently used in the surveillance of Barretts esophagus patients. Our integrated thermal therapy delivery and monitoring platform consists of a flexible, customized bipolar RFA electrode array designed for use with a clinical balloon OCT catheter and a processing algorithm to accurately map the thermal coagulation process. Non-uniform rotation distortion was ...
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    24. Comparing the Risk Factors of Plaque Rupture and Failed Plaque Healing in Acute Coronary Syndrome

      Comparing the Risk Factors of Plaque Rupture and Failed Plaque Healing in Acute Coronary Syndrome
      The article by Vergallo et al 1 in this issue of JAMA Cardiology supports a hypothesis that healed plaques are a marker for reduced acute coronary syndrome (ACS) risk. This commentary expands on this idea by examining a mechanistic hypothesis of their results beyond looking at healing just as a marker. Specifically, failed healing, which correlated in the study by Vergallo et al 1 with long core axial extent, predisposes ...
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    25. 1-24 of 139 1 2 3 4 5 6 »
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  2. Organizations in the News

    1. (82 articles) Massachusetts General Hospital
    2. (18 articles) Brigham and Women’s Hospital
    3. (11 articles) Beth Israel Deaconess Medical Center
    4. (7 articles) Tufts University
    5. (7 articles) Boston University
    6. (6 articles) National Institutes of Health
    7. (6 articles) University of Pittsburgh
    8. (6 articles) Massachusetts Eye and Ear Infirmary
    9. (5 articles) Oregon Health & Science University
    10. (5 articles) Korea Advanced Institute of Science and Technology
    11. (5 articles) Erasmus University
    12. (5 articles) University of Southern California
  3. OCT Companies in the News

    1. (11 articles) Thorlabs
    2. (10 articles) Abbott
    3. (6 articles) Praevium Research
    4. (4 articles) Carl Zeiss Meditec
    5. (3 articles) NinePoint Medical
    6. (2 articles) Visionix
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    8. (1 articles) Heidelberg Engineering
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    10. (1 articles) Tomey Corporation