1. Articles from Yonatan Winetraub

    1-7 of 7
    1. Upper limit for angular compounding speckle reduction

      Upper limit for angular compounding speckle reduction

      Angular compounding is a technique for reducing speckle noise in optical coherence tomography that is claimed to significantly improve the signal-to-noise ratio (SNR) of images without impairing their spatial resolution. Here, we examine how focal point movements caused by optical aberrations in an angular compounding system may produce unintended spatial averaging and concomitant loss of spatial resolution. Experimentally, we accounted for such aberrations by aligning our system and measuring distortions in images and found that when the distortions were corrected, the speckle reduction by angular compounding was limited. Our theoretical analysis using Monte Carlo simulations indicates that “pure” angular compounding ...

      Read Full Article
    2. Real-time detection of circulating tumor cells in living animals using functionalized large gold nanorods

      Real-time detection of circulating tumor cells in living animals using functionalized large gold nanorods

      Optical coherence tomography (OCT) can be utilized with significant speckle reduction techniques and highly-scattering contrast agents for noninvasive, contrast-enhanced imaging of living tissues at the cellular scale. The advantages of reduced speckle noise and improved targeted contrast can be harnessed to track objects as small as 2 μm in vivo, which enables applications for cell tracking and quantification in living subjects. Here we demonstrate the use of Large Gold Nanorods (LGNRs) as contrast agents for detecting individual micron-sized polystyrene beads and single myeloma cells in blood circulation using speckle modulating-OCT (SM-OCT). This report marks the first time that OCT has ...

      Read Full Article
    3. Gold Nanoprisms as Optical Coherence Tomography Contrast Agents in the Second Near-Infrared Window for Enhanced Angiography in Live Animals

      Gold Nanoprisms as Optical Coherence Tomography Contrast Agents in the Second Near-Infrared Window for Enhanced Angiography in Live Animals

      Optical coherence tomography angiography (OCTA) is an important tool for investigating vascular networks and microcirculation in living tissue. Traditional OCTA detects blood vessels via intravascular dynamic scattering signals derived from the movements of red blood cells (RBCs). However, the low hematocrit and long latency between RBCs in capillaries make these OCTA signals discontinuous, leading to incomplete mapping of the vascular networks. OCTA imaging of microvascular circulation is particularly challenging in tumors due to the abnormally slow blood flow in angiogenic tumor vessels and strong attenuation of light by tumor tissue. Here, we demonstrate in vivo that gold nanoprisms (GNPRs) can ...

      Read Full Article
    4. Optical coherence tomography of lymphatic vessel endothelial hyaluronan receptors in vivo

      Optical coherence tomography of lymphatic vessel endothelial hyaluronan receptors in vivo

      Optical Coherence Tomography (OCT) imaging of living subjects offers millimeters depth of penetration into tissue while maintaining high spatial resolution. However, because most molecular biomarkers do not produce inherent OCT contrast signals, exogenous contrast agents must be employed to achieve molecular imaging. Here we demonstrate that microbeads (μBs) can be used as effective contrast agents to target cellular biomarkers in lymphatic vessels and can be detected by OCT using a phase variance algorithm. We applied this technique to image the molecular dynamics of lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) in vivo , which showed significant down-regulation during tissue inflammation.

      Read Full Article
    5. In Vivo Molecular Optical Coherence Tomography of Lymphatic Vessel Endothelial Hyaluronan Receptors

      In Vivo Molecular Optical Coherence Tomography of Lymphatic Vessel Endothelial Hyaluronan Receptors

      Optical Coherence Tomography (OCT) imaging of living subjects offers increased depth of penetration while maintaining high spatial resolution when compared to other optical microscopy techniques. However, since most protein biomarkers do not exhibit inherent contrast detectable by OCT, exogenous contrast agents must be employed for imaging specific cellular biomarkers of interest. While a number of OCT contrast agents have been previously studied, demonstrations of molecular targeting with such agents in live animals have been historically challenging and notably limited in success. Here we demonstrate for the first time that microbeads (µBs) can be used as contrast agents to target cellular ...

      Read Full Article
    6. A model for quantifying contrast enhancement in optical coherence tomography (OCT)

      A model for quantifying contrast enhancement in optical coherence tomography (OCT)

      We have developed a model to accurately quantify the signals produced by exogenous scattering agents used for contrast-enhanced Optical Coherence Tomography (OCT). This model predicts distinct concentration-dependent signal trends that arise from the underlying physics of coherence-based detection. Accordingly, we show that real scattering particles can be described as simplified ideal scatterers with modified scattering intensity and concentration. The relation between OCT signal and particle concentration is approximately linear at concentrations lower than 0.8 particles per imaging voxel. However, at higher concentrations, interference effects cause signal to increase with a square root dependence on the number of particles within ...

      Read Full Article
    7. Quantitative contrast-enhanced optical coherence tomography

      Quantitative contrast-enhanced optical coherence tomography

      We have developed a model to accurately quantify the signals produced by exogenous scattering agents used for contrast-enhanced Optical Coherence Tomography (OCT). This model predicts distinct concentration-dependent signal trends that arise from the underlying physics of OCT detection. Accordingly, we show that real scattering particles can be described as simplified ideal scatterers with modified scattering intensity and concentration. The relation between OCT signal and particle concentration is approximately linear at concentrations lower than 0.8 particle per imaging voxel. However, at higher concentrations, interference effects cause signal to increase with a square root dependence on the number of particles within ...

      Read Full Article
    1-7 of 7
  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. Topics in the News

    1. (7 articles) Stanford University
    2. (7 articles) Adam de la Zerda
    3. (5 articles) Orly Liba
    4. (4 articles) Elliott D. SoRelle
    5. (3 articles) Siavash Yousefi
    6. (2 articles) Debasish Sen
  3. Popular Articles

  4. Picture Gallery

    Quantitative contrast-enhanced optical coherence tomography A model for quantifying contrast enhancement in optical coherence tomography (OCT) In Vivo Molecular Optical Coherence Tomography of Lymphatic Vessel Endothelial Hyaluronan Receptors Optical coherence tomography of lymphatic vessel endothelial hyaluronan receptors in vivo Gold Nanoprisms as Optical Coherence Tomography Contrast Agents in the Second Near-Infrared Window for Enhanced Angiography in Live Animals Real-time detection of circulating tumor cells in living animals using functionalized large gold nanorods Upper limit for angular compounding speckle reduction Measurement of the Shrinkage of Natural and Simulated Lesions on Root Surfaces using CP-OCT Optic-Net: A Novel Convolutional Neural Network for Diagnosis of Retinal Diseases from Optical Tomography Images Double layer sign: A new optical coherence tomography finding in active tubercular serpiginous-like choroiditis to monitor activity Influence of Epiretinal Membranes on the Retinal Nerve Fiber Layer Thickness Measured by Spectral Domain Optical Coherence Tomography in Glaucoma High signal-to-noise ratio reconstruction of low bit-depth optical coherence tomography using deep learning