1. Articles from brian c. wilson

    1-12 of 12
    1. Optical clearing of melanoma in vivo: characterization by diffuse reflectance spectroscopy and optical coherence tomography

      Optical clearing of melanoma in vivo: characterization by diffuse reflectance spectroscopy and optical coherence tomography

      Melanoma is the most aggressive type of skin cancer, with significant risk of fatality. Due to its pigmentation, light-based imaging and treatment techniques are limited to near the tumor surface, which is inadequate, for example, to evaluate the microvascular density that is associated with prognosis. White-light diffuse reflectance spectroscopy (DRS) and near-infrared optical coherence tomography (OCT) were used to evaluate the effect of a topically applied optical clearing agent (OCA) in melanoma in vivo and to image the microvascular network. DRS was performed using a contact fiber optic probe in the range from 450 to 650 nm. OCT imaging was ...

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    2. Method for identifying malignancies in barrett's esophagus using white light endoscopy

      Method for identifying malignancies in barrett's esophagus using white light endoscopy

      A method is described for computing a statistically significant difference between dysplasia and Barrett's esophagus (both with and without inflammatory component) using a discriminate function with diffuse reflectance measurements performed at a minimum of four different wavelengths of 485, 513, 598, and 629 nm. The discriminate function found depends both on local blood fraction volume T.sub.HB and oxygenation SO.sub.2. A pull-back approach of spectral data acquisition is disclosed which takes into account tissue motility in esophagus and measurement geometry peculiarities. The pull-back approach provides a significant improvement of measurement reproducibility and reduction of data deviation ...

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    3. Real-time speckle variance swept-source optical coherence tomography using a graphics processing unit

      Real-time speckle variance swept-source optical coherence tomography using a graphics processing unit

      Abstract: Advances in swept source laser technology continues to increase the imaging speed of swept-source optical coherence tomography (SS-OCT) systems. These fast imaging speeds are ideal for microvascular detection schemes, such as speckle variance (SV), where interframe motion can cause severe imaging artifacts and loss of vascular contrast. However, full utilization of the laser scan speed has been hindered by the computationally intensive signal processing required by SS-OCT and SV calculations. Using a commercial graphics processing unit that has been optimized for parallel data processing, we report a complete high-speed SS-OCT platform capable of real-time data acquisition, processing, display, and ...

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    4. Speckle variance optical coherence tomography of the rodent spinal cord: in vivo feasibility

      Speckle variance optical coherence tomography of the rodent spinal cord: in vivo feasibility

      Optical coherence tomography (OCT) has the combined advantage of high temporal (µsec) and spatial (less than 10µm) resolution. These features make it an attractive tool to study the dynamic relationship between neural activity and the surrounding blood vessels in the spinal cord, a topic that is poorly understood. Here we present work that aims to optimize an in vivo OCT imaging model of the rodent spinal cord. In this study we image the microvascular networks of both rats and mice using speckle variance OCT. This is the first report of depth resolved imaging of the in vivo spinal cord using ...

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    5. Optimized speckle variance OCT imaging of microvasculature

      Optimized speckle variance OCT imaging of microvasculature
      We optimize speckle variance optical coherence tomography (svOCT) imaging of microvasculature in high and low bulk tissue motion scenarios. To achieve a significant level of image contrast, frame rates must be optimized such that tissue displacement between frames is less than the beam radius. We demonstrate that higher accuracy estimates of speckle variance can enhance the detection of capillaries. These findings are illustrated in vivo by imaging the dorsal window chamber model (low bulk motion). We also show svOCT imaging of the nonstabilized finger (high bulk motion), using optimized imaging parameters, demonstrating better vessel detection than Doppler OCT.
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    6. Oxygen-independent degradation of HIF- via bioengineered VHL tumour suppressor complex

      Tumour hypoxia promotes the accumulation of the otherwise oxygen-labile hypoxia-inducible factor (HIF)- subunit whose expression is associated with cancer progression, poor prognosis and resistance to conventional radiation and chemotherapy. The oxygen-dependent degradation of HIF- is carried out by the von Hippel-Lindau (VHL) protein-containing E3 that directly binds and ubiquitylates HIF- for subsequent proteasomal destruction. Thus, the cellular proteins involved in the VHL-HIF pathway have been recognized as attractive molecular targets for cancer therapy. However, the various compounds designed to inhibit HIF- or HIF-downstream targets, although promising, have shown limited success in the clinic. In the present study, we describe the ...
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    7. Interstitial Doppler Optical Coherence Tomography as a Local Tumor Necrosis Predictor in Photodynamic Therapy of Prostatic Carcinoma: An In vivo Study

      We have tested the feasibility of real-time localized blood flow measurements, obtained with interstitial (IS) Doppler optical coherence tomography (DOCT), to predict photodynamic therapy (PDT)-induced tumor necrosis deep within solid Dunning rat prostate tumors. IS-DOCT was used to quantify the PDT-induced microvascular shutdown rate in s.c. Dunning prostate tumors (n = 28). Photofrin (12.5 mg/kg) was administered 20 to 24 hours before tumor irradiation, with 635 nm surface irradiance of 8 to 133 mWcm–2 for 25 minutes. High frequency ultrasound and calipers were used to measure the thickness of the skin covering the tumor and the ...
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    8. Intravital high-resolution optical imaging of individual vessel response to photodynamic treatment

      Mamta Khurana, Eduardo H. Moriyama, Adrian Mariampillai et al. Intravital imaging using confocal microscopy facilitates high-resolution studies of cellular and molecular events in vivo. We use this, complemented by Doppler optical coherence tomography (OCT), to assess blood flow in a mouse dorsal skin-fold window chamber model to image the response of individua ... [J. Biomed. Opt. 13, 040502 (2008)] published Fri Aug 29, 2008.
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    9. Advanced Photodynamic Therapy

      Photodynamic therapy (PDT) is the use of drugs (photosensitizers) that are activated by visible or near infrared light to produce specific biological effects in cells or tissues [1]. The basic steps in a PDT treatment are application of the photosensitizer (systemically or topically), a time interval to allow for photosensitizer accumulation in the target diseased tissue or cells, and illumination of the target area or volume with light of an appropriate wavelength to activate the sensitizer. PDT is a highly multidisciplinary topic, involving optical biophysics and bioengineering, synthetic chemistry, pharmacology, photophysics and photochemistry, photobiology, and different clinical specialties. The main ...
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    10. Speckle variance detection of microvasculature using swept-source optical coherence tomography

      Speckle variance detection of microvasculature using swept-source optical coherence tomography
      Adrian Mariampillai, Beau A. Standish, Eduardo H. Moriyama, Mamta Khurana, Nigel R. Munce, Michael K. Leung, James Jiang, Alex Cable, Brian C. Wilson, I. Alex Vitkin, Victor X. Yang. We report on imaging of microcirculation by calculating the speckle variance of optical coherence tomography (OCT) structural images acquired using a Fourier domain mode-locked swept-wavelength laser. The algorithm calculates interframe speckle variance in two-dimensional and three-dimensional OCT ... [Opt. Lett. 33, 1530-1532 (2008)]
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    11. Detection and treatment of dysplasia in Barrett's esophagus: a pivotal challenge in translating biophotonics from bench to bedside

      Brian C. Wilson Barrett's esophagus (BE) is a condition that poses high risk of developing dysplasia leading to cancer. Detection of dysplasia is a critical element in determining therapy but is extremely challenging, so that standard white-light endoscopy is used only as a means to guide biopsy. Many novel optical ... [J. Biomed. Opt. 12, 051401 (2007)] published Thu Nov 1, 2007.
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    12. Method and apparatus for high resolution coherent optical imaging

      A method and an apparatus for examining the subsurface microstructure of a sample are provided. Radiation from a plurality of optical radiation sources travels along a first optical path. In the first optical path, a device focuses the optical radiati n from each of the optical sources into a plurality of respective focal points along the first optical path to provide substantially continuous coverage of a selected portion of the first optical path. Then, a sample on the first optical path within the selected length extending into the sample is scanned along said selected portion of the first optical path.
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    1-12 of 12
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  2. Topics in the News

    1. (12 articles) Brian C. Wilson
    2. (11 articles) University of Toronto
    3. (7 articles) Adrian Mariampillai
    4. (6 articles) Victor X. D. Yang
    5. (6 articles) I. Alex Vitkin
    6. (4 articles) Ontario Cancer Institute
    7. (4 articles) Ryerson University
    8. (4 articles) Kenneth K. C. Lee
    9. (4 articles) Beau A. Standish
    10. (3 articles) National Institutes of Health
    11. (2 articles) Nigel R. Munce
    12. (2 articles) Harvard University
    13. (2 articles) Northwestern University
    14. (1 articles) University of Southern California
    15. (1 articles) Texas A&M University
    16. (1 articles) FDA
    17. (1 articles) Dresden University of Technology
    18. (1 articles) Edmund Koch
    19. (1 articles) Lars Kirsten
    20. (1 articles) Javier A. Jo
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    Speckle variance detection of microvasculature using swept-source optical coherence tomography Optimized speckle variance OCT imaging of microvasculature Speckle variance optical coherence tomography of the rodent spinal cord: in vivo feasibility Real-time speckle variance swept-source optical coherence tomography using a graphics processing unit Medical treatment of inflammatory punctual stenosis monitored by anterior segment optical coherence tomography Development and Validation of a Deep Learning System for Diagnosing Glaucoma Using Optical Coherence Tomography Methylene blue-filled biodegradable polymer particles as a contrast agent for optical coherence tomography Optical coherence tomography for thyroid pathology: 3D analysis of tissue microstructure Mathematical Analysis of Texture Indicators for the Segmentation of Optical Coherence Tomography Images Comparison of Current Optical Coherence Tomography Angiography Methods in Imaging Retinal Hemangioblastomas New findings useful for clinical practice using swept-source optical coherence tomography angiography in the follow-up of active ocular toxoplasmosis Ultrafast-laser ablation of polymer multicore fibers enhances biomedical sensing