1. Articles from Joshua Pfefer

    1-5 of 5
    1. Quantitative analysis of low contrast detectability in optical coherence tomography

      Quantitative analysis of low contrast detectability in optical coherence tomography

      Optical coherence tomography (OCT) is a high resolution imaging technology that is rapidly being adopted as the standard of care for medical applications such as ocular and intravascular imaging. However, clinical translation has been hampered by the lack of standardized test methods for performance evaluation as well as consensus standards analogous to those that have been developed for established medical imaging modalities (e.g., ultrasound). In this study, we address low contrast detectability, specifically, the ability of systems to differentiate between regions exhibiting small differences in scattering coefficient. Based on standard test methods for established medical imaging modalities, we have ...

      Read Full Article
    2. Quantitative assessment of biophotonic imaging system performance with phantoms fabricated by rapid prototyping

      Quantitative assessment of biophotonic imaging system performance with phantoms fabricated by rapid prototyping

      In biophotonic imaging, turbid phantoms that are low-cost, biologically-relevant, and durable are desired for standardized performance assessment. Such phantoms often contain inclusions of varying depths and sizes in order to quantify key image quality characteristics such as penetration depth, sensitivity and contrast detectability. The emerging technique of rapid prototyping with three-dimensional (3D) printers provides a potentially revolutionary way to fabricate these structures. Towards this goal, we have characterized the optical properties and morphology of phantoms fabricated by two 3D printing approaches: thermosoftening and photopolymerization. Material optical properties were measured by spectrophotometry while the morphology of phantoms incorporating 0.2-1.0 ...

      Read Full Article
    3. Multi-system comparison of optical coherence tomography performance with point spread function phantoms

      Multi-system comparison of optical coherence tomography performance with point spread function phantoms

      Point spread function (PSF) phantoms based on unstructured distributions of sub-resolution particles in a transparent matrix have proven effective for evaluating resolution and its spatial variation in optical coherence tomography (OCT) systems. Measurements based on PSF phantoms have the potential to become a standard test method for consistent, objective and quantitative inter-comparison of OCT system performance. Towards this end, we have evaluated three PSF phantoms and investigated their ability to compare the performance of four OCT systems. The phantoms are based on 260-nm-diameter gold nanoshells, submicron-diameter iron oxide particles and 1.5-micron-diameter silica particles. The OCT systems included spectral-domain and ...

      Read Full Article
    4. A review of consensus test methods for established medical imaging modalities and their implications for optical coherence tomography

      A review of consensus test methods for established medical imaging modalities and their implications for optical coherence tomography

      In recent years there has been increasing interest in development of consensus, tissue-phantom-based approaches for assessment of biophotonic imaging systems, with the primary goal of facilitating clinical translation of novel optical technologies. Well-characterized test methods based on tissue phantoms can provide useful tools for performance assessment, thus enabling standardization and device inter-comparison during preclinical development as well as quality assurance and re-calibration in the clinical setting. In this review, we study the role of phantom-based test methods as described in consensus documents such as international standards for established imaging modalities including X-ray CT, MRI and ultrasound. Specifically, we focus on ...

      Read Full Article
      Mentions: FDA Anant Agrawal
    5. Optical coherence tomography imaging of retinal damage in real time under a stimulus electrode

      Optical coherence tomography imaging of retinal damage in real time under a stimulus electrode

      We have developed a novel method to study the effects of electrical stimulation of the local retina directly under an epiretinal stimulus electrode in real time. Using optical coherence tomography (OCT) and a superfused retinal eyecup preparation, we obtained high-resolution images of the rabbit retina directly under an optically transparent saline-filled fluoropolymer stimulation tube electrode. During OCT imaging, 50 Hz trains of biphasic current pulses 1 ms/phase (23–749 µC cm−2 ph−1) were applied to the retinal surface for 5 min. After imaging, the stimulated regions were stained with the dye propidium iodide (PI) to reveal cytotoxic ...

      Read Full Article
    1-5 of 5
  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. (5 articles) FDA
    2. (4 articles) University of Maryland
    3. (4 articles) Anant Agrawal
    4. (3 articles) Yu Chen
    5. (2 articles) Chia-Pin Liang
    6. (1 articles) University of London
    7. (1 articles) UK National Physical Laboratory
    8. (1 articles) Pete H. Tomlins
    9. (1 articles) Ethan D. Cohen
    10. (1 articles) Physical Sciences Incorporated
    11. (1 articles) UCLA
    12. (1 articles) University of Wisconsin
    13. (1 articles) University of St. Andrews
    14. (1 articles) Duke University
    15. (1 articles) Kishan Dholakia
    16. (1 articles) Cynthia A. Toth
    17. (1 articles) Richard B. Rosen
    18. (1 articles) Optovue
    19. (1 articles) Leica
    20. (1 articles) Heidelberg Engineering
  3. Popular Articles

  4. Picture Gallery

    Optical coherence tomography imaging of retinal damage in real time under a stimulus electrode A review of consensus test methods for established medical imaging modalities and their implications for optical coherence tomography Multi-system comparison of optical coherence tomography performance with point spread function phantoms Quantitative assessment of biophotonic imaging system performance with phantoms fabricated by rapid prototyping Quantitative analysis of low contrast detectability in optical coherence tomography Monitoring Response to Platelet-Rich Plasma in Patients with Alopecia Areata with Optical Coherence Tomography: A Case Series NONPERFUSION AREA QUANTIFICATION IN BRANCH RETINAL VEIN OCCLUSION: A WIDEFIELD OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY STUDY Nonperfusion Assessment in Retinal Vein Occlusion: Comparison between Ultra-Widefield Fluorescein Angiography and Widefield OCT-Angiography Anatomical Location of the Raphe and Extended Raphe in the Human Retina: Implications for Assessment of the Optic Nerve with OCT Assessing the Influence of OCT-A Device and Scan Size on Retinal Vascular Metrics Repeatability and Reproducibility of Axial and Lateral Measurements on Handheld Optical Coherence Tomography Systems Compared with Tabletop System Bleb Morphology Using Anterior-Segment Optical Coherence Tomography after Ahmed Glaucoma Valve Surgery with Tenon Capsule Resection