1. Articles from Geoffrey Hohert

    1-5 of 5
    1. Correction of motion artifacts in endoscopic optical coherence tomography and autofluorescence images based on azimuthal en face image registration

      Correction of motion artifacts in endoscopic optical coherence tomography and autofluorescence images based on azimuthal en face image registration

      We present a method for the correction of motion artifacts present in two- and three-dimensional in vivoendoscopic images produced by rotary-pullback catheters. This method can correct for cardiac/breathing-based motion artifacts and catheter-based motion artifacts such as nonuniform rotational distortion (NURD). This method assumes that en face tissue imaging contains slowly varying structures that are roughly parallel to the pullback axis. The method reduces motion artifacts using a dynamic time warping solution through a cost matrix that measures similarities between adjacent frames in en face images. We optimize and demonstrate the suitability of this method using a real and ...

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    2. Dual-beam manually-actuated distortion-corrected imaging (DMDI) with micromotor catheters

      Dual-beam manually-actuated distortion-corrected imaging (DMDI) with micromotor catheters

      e present a new paradigm for performing two-dimensional scanning called dual-beam manually-actuated distortion-corrected imaging (DMDI). DMDI operates by imaging the same object with two spatially-separated beams that are being mechanically scanned rapidly in one dimension with slower manual actuation along a second dimension. Registration of common features between the two imaging channels allows remapping of the images to correct for distortions due to manual actuation. We demonstrate DMDI using a 4.7 mm OD rotationally scanning dual-beam micromotor catheter (DBMC). The DBMC requires a simple, one-time calibration of the beam paths by imaging a patterned phantom. DMDI allows for distortion ...

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    3. Endoscopic Doppler optical coherence tomography and autofluorescence imaging of peripheral pulmonary nodules and vasculature

      Endoscopic Doppler optical coherence tomography and autofluorescence imaging of peripheral pulmonary nodules and vasculature

      We present the first endoscopic Doppler optical coherence tomography and co-registered autofluorescence imaging (DOCT-AFI) of peripheral pulmonary nodules and vascular networks in vivo using a small 0.9 mm diameter catheter. Using exemplary images from volumetric data sets collected from 31 patients during flexible bronchoscopy, we demonstrate how DOCT and AFI offer complementary information that may increase the ability to locate and characterize pulmonary nodules. AFI offers a sensitive visual presentation for the rapid identification of suspicious airway sites, while co-registered OCT provides detailed structural information to assess the airway morphology. We demonstrate the ability of AFI to visualize vascular ...

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    4. Doppler optical coherence tomography and co-registered autofluorescence imaging of peripheral lung cancer

      Doppler optical coherence tomography and co-registered autofluorescence imaging of peripheral lung cancer

      Diagnosis of peripheral lung nodules is challenging because they are rarely visualized endobronchially. Imaging techniques such as endobronchial ultrasound (EBUS) are employed to improve tumor localization. The current EBUS probe provides limited nodule characterization and has an outer diameter of 1.4 mm that restricts access to small peripheral airways. We report a novel co-registered autofluoresence Doppler optical coherence tomography (AF/DOCT) system with a 0.9 mm diameter probe to characterize peripheral lung nodules prior to biopsy in vivo. Method: Patients referred for evaluation of peripheral lung nodules underwent bronchoscopy with examination of standard EBUS and the novel AF ...

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    5. A high-efficiency fiber-based imaging system for co-registered autofluorescence and optical coherence tomography

      A high-efficiency fiber-based imaging system for co-registered autofluorescence and optical coherence tomography

      We present a power-efficient fiber-based imaging system capable of co-registered autofluorescence imaging and optical coherence tomography (AF/OCT). The system employs a custom fiber optic rotary joint (FORJ) with an embedded dichroic mirror to efficiently combine the OCT and AF pathways. This three-port wavelength multiplexing FORJ setup has a throughput of more than 83% for collected AF emission, significantly more efficient compared to previously reported fiber-based methods. A custom 900 µm diameter catheter ‒ consisting of a rotating lens assembly, double-clad fiber (DCF), and torque cable in a stationary plastic tube ‒ was fabricated to allow AF/OCT imaging of small airways ...

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    1-5 of 5
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  2. Topics in the News

    1. (5 articles) British Columbia Cancer Agency
    2. (5 articles) Pierre M. Lane
    3. (4 articles) Stephen Lam
    4. (4 articles) Hamid Pahlevaninezhad
    5. (3 articles) Tawimas Shaipanich
    6. (2 articles) Wei Zhang
    7. (2 articles) Lucas Cahill
    8. (2 articles) UC Irvine
    9. (1 articles) Ryerson University
    10. (1 articles) Matthew Brenner
    11. (1 articles) Victor X. D. Yang
    12. (1 articles) National University of Singapore
    13. (1 articles) University Federico II
    14. (1 articles) University of Copenhagen
    15. (1 articles) Cardiff University
    16. (1 articles) Nanyang Technological University
    17. (1 articles) Gregor B. E. Jemec
    18. (1 articles) Friedemann Paul
    19. (1 articles) Lotte Themstrup
    20. (1 articles) Carl Zeiss Meditec
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    A high-efficiency fiber-based imaging system for co-registered autofluorescence and optical coherence tomography Doppler optical coherence tomography and co-registered autofluorescence imaging of peripheral lung cancer Endoscopic Doppler optical coherence tomography and autofluorescence imaging of peripheral pulmonary nodules and vasculature Dual-beam manually-actuated distortion-corrected imaging (DMDI) with micromotor catheters Correction of motion artifacts in endoscopic optical coherence tomography and autofluorescence images based on azimuthal en face image registration Normative data and minimally detectable change for inner retinal layer thicknesses using a semi-automated OCT image segmentation pipeline Acoustic Radiation Force Optical Coherence Elastography Advances in Optical Coherence Tomography and Confocal Laser Endomicroscopy in Pulmonary Diseases To Evaluate the Effect of Chronic Obstructive Pulmonary Disease on Retinal and Choroidal Thicknesses Measured by Optical Coherence Tomography Neovascularized Best Disease in Child: Contribution of Optical Coherence Tomography Angiography DeshadowGAN: A Deep Learning Approach to Remove Shadows from Optical Coherence Tomography Images Optical coherence tomography of onychomycosis: proposed terminology and a suggestion of practical usage