1. Articles from Weicheng Wu

    1-9 of 9
    1. Statistical intensity variation analysis for rapid volumetric imaging of capillary network flux

      Statistical intensity variation analysis for rapid volumetric imaging of capillary network flux

      We present a novel optical coherence tomography (OCT)-based technique for rapid volumetric imaging of red blood cell (RBC) flux in capillary networks. Previously we reported that OCT can capture individual RBC passage within a capillary, where the OCT intensity signal at a voxel fluctuates when an RBC passes the voxel. Based on this finding, we defined a metric of statistical intensity variation (SIV) and validated that the mean SIV is proportional to the RBC flux [RBC/s] through simulations and measurements. From rapidly scanned volume data, we used Hessian matrix analysis to vectorize a segment path of each capillary ...

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    2. Multiple-capillary measurement of RBC speed, flux, and density with optical coherence tomography

      Multiple-capillary measurement of RBC speed, flux, and density with optical coherence tomography

      As capillaries exhibit heterogeneous and fluctuating dynamics even during baseline, a technique measuring red blood cell (RBC) speed and flux over many capillaries at the same time is needed. Here, we report that optical coherence tomography can capture individual RBC passage simultaneously over many capillaries located at different depths. Further, we demonstrate the ability to quantify RBC speed, flux, and linear density. This technique will provide a means to monitor microvascular flow dynamics over many capillaries at different depths at the same time.

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    3. Quantitative imaging of cerebral blood flow velocity and intracellular motility using dynamic light scattering–optical coherence tomography

      Quantitative imaging of cerebral blood flow velocity and intracellular motility using dynamic light scattering–optical coherence tomography

      This paper describes a novel optical method for label-free quantitative imaging of cerebral blood flow (CBF) and intracellular motility (IM) in the rodent cerebral cortex. This method is based on a technique that integrates dynamic light scattering (DLS) and optical coherence tomography (OCT), named DLS–OCT. The technique measures both the axial and transverse velocities of CBF, whereas conventional Doppler OCT measures only the axial one. In addition, the technique produces a three-dimensional map of the diffusion coefficient quantifying nontranslational motions. In the DLS–OCT diffusion map, we observed high-diffusion spots, whose locations highly correspond to neuronal cell bodies and ...

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    4. Dynamic light scattering optical coherence tomography

      Dynamic light scattering optical coherence tomography

      We introduce an integration of dynamic light scattering (DLS) and optical coherence tomography (OCT) for high-resolution 3D imaging of heterogeneous diffusion and flow. DLS analyzes fluctuations in light scattered by particles to measure diffusion or flow of the particles, and OCT uses coherence gating to collect light only scattered from a small volume for high-resolution structural imaging. Therefore, the integration of DLS and OCT enables high-resolution 3D imaging of diffusion and flow. We derived a theory under the assumption that static and moving particles are mixed within the OCT resolution volume and the moving particles can exhibit either diffusive or ...

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    5. Optical coherence tomography for the quantitative study of cerebrovascular physiology

      Optical coherence tomography for the quantitative study of cerebrovascular physiology

      Doppler optical coherence tomography (DOCT) and OCT angiography are novel methods to investigate cerebrovascular physiology. In the rodent cortex, DOCT flow displays features characteristic of cerebral blood flow, including conservation along nonbranching vascular segments and at branch points. Moreover, DOCT flow values correlate with hydrogen clearance flow values when both are measured simultaneously. These data validate DOCT as a noninvasive quantitative method to measure tissue perfusion over a physiologic range.

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    6. Microvascular oxygen tension and flow measurements in rodent cerebral cortex during baseline conditions and functional activation

      Microvascular oxygen tension and flow measurements in rodent cerebral cortex during baseline conditions and functional activation

      Measuring cerebral oxygen delivery and metabolism microscopically is important for interpreting macroscopic functional magnetic resonance imaging (fMRI) data and identifying pathological changes associated with stroke, Alzheimer's disease, and brain injury. Here, we present simultaneous, microscopic measurements of cerebral blood flow (CBF) and oxygen partial pressure (pO(2)) in cortical microvessels of anesthetized rats under baseline conditions and during somatosensory stimulation. Using a custom-built imaging system, we measured CBF with Fourier-domain optical coherence tomography (OCT), and vascular pO(2) with confocal phosphorescence lifetime microscopy. Cerebral blood flow and pO(2) measurements displayed heterogeneity over distances irresolvable with fMRI and positron ...

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    7. Quantitative cerebral blood flow with Optical Coherence Tomography

      Quantitative cerebral blood flow with Optical Coherence Tomography

      Vivek J. Srinivasan, Sava Sakadžić, Iwona Gorczynska, Svetlana Ruvinskaya, Weicheng Wu, James G. Fujimoto, David A. BoasAbsolute measurements of cerebral blood flow (CBF) are an important endpoint in studies of cerebral pathophysiology. Currently no accepted method exists for in vivo longitudinal monitoring of CBF with high resolution in rats and mice. Using three-dimensional Doppler Optical Coherence Tomography and ... [Opt. Express 18, 2477-2494 (2010)]

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    8. Rapid volumetric angiography of cortical microvasculature with optical coherence tomography

      Rapid volumetric angiography of cortical microvasculature with optical coherence tomography

      We describe methods and algorithms for rapid volumetric imaging of cortical vasculature with optical coherence tomography (OCT). By optimizing system design, scanning protocols, and algorithms for visualization of capillary flow, comprehensive imaging of the surface pial vasculature and capillary bed is performed in approximately 12 s. By imaging during hypercapnia and comparing with simultaneous CCD imaging, the sources of contrast of OCT angiography are investigated.

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    9. Depth-resolved microscopy of cortical hemodynamics with optical coherence tomography

      Depth-resolved microscopy of cortical hemodynamics with optical coherence tomography

      We describe depth-resolved microscopy of cortical hemodynamics with high-speed spectral/Fourier domain optical coherence tomography (OCT). Stimulus-evoked changes in blood vessel diameter, flow, and total hemoglobin were measured in the rat somatosensory cortex. The results show OCT measurements of hemodynamic changes during functional activation and represent an important step toward understanding functional hyperemia at the microscopic level.

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    1-9 of 9
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  2. Topics in the News

    1. (9 articles) David A. Boas
    2. (7 articles) Harvard University
    3. (7 articles) Massachusetts General Hospital
    4. (5 articles) Vivek J. Srinivasan
    5. (4 articles) Massachusetts Institute of Technology
    6. (4 articles) Harsha Radhakrishnan
    7. (4 articles) James Y. Jiang
    8. (4 articles) Thorlabs
    9. (3 articles) James G. Fujimoto
    10. (3 articles) Iwona Gorczynska
    11. (1 articles) Yamagata University
    12. (1 articles) Bern University of Applied Sciences
    13. (1 articles) Medical University of Vienna
    14. (1 articles) University of Maryland
    15. (1 articles) Koen A. Vermeer
    16. (1 articles) Vishali Gupta
    17. (1 articles) Bernhard Baumann
    18. (1 articles) Brandon J. Lujan
    19. (1 articles) Antonia Lichtenegger
    20. (1 articles) OCTLIGHT
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    Depth-resolved microscopy of cortical hemodynamics with optical coherence tomography Rapid volumetric angiography of cortical microvasculature with optical coherence tomography Quantitative cerebral blood flow with Optical Coherence Tomography Microvascular oxygen tension and flow measurements in rodent cerebral cortex during baseline conditions and functional activation Optical coherence tomography for the quantitative study of cerebrovascular physiology Dynamic light scattering optical coherence tomography Quantitative imaging of cerebral blood flow velocity and intracellular motility using dynamic light scattering–optical coherence tomography Multiple-capillary measurement of RBC speed, flux, and density with optical coherence tomography Statistical intensity variation analysis for rapid volumetric imaging of capillary network flux Hybrid registration of retinal fluorescein angiography and optical coherence tomography images of patients with diabetic retinopathy Optical Coherence Tomography Angiography Quality Across Three Multicenter Clinical Studies of Diabetic Retinopathy The Role of Optical Coherence Tomography Angiography(OCTA) in Detecting Choroidal Neovascularization in DifferentStages of Best Macular Dystrophy: A Case Series