1. Articles from Caroline Boudoux

    1-24 of 24
    1. Coregistered optical coherence tomography and frequency-encoded multispectral imaging for spectrally sparse color imagingv

      Coregistered optical coherence tomography and frequency-encoded multispectral imaging for spectrally sparse color imagingv

      We present a system combining optical coherence tomography (OCT) and multispectral imaging (MSI) for coregistered structural imaging and surface color imaging. We first describe and numerically validate an optimization model to guide the selection of the MSI wavelengths and their relative intensities. We then demonstrate the integration of this model into an all-fiber bench-top system. We implement frequency-domain multiplexing for the MSI to enable concurrent acquisition of both OCT and MSI at OCT acquisition rates. Such a system could be implemented in endoscopic practices to provide multimodal, high-resolution imaging of deep organ structures that are currently inaccessible to standard video ...

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    2. Simple and robust calibration procedure for k-linearization and dispersion compensation in optical coherence tomography

      Simple and robust calibration procedure for k-linearization and dispersion compensation in optical coherence tomography

      In Fourier-domain optical coherence tomography (FD-OCT), proper signal sampling and dispersion compensation are essential steps to achieve optimal axial resolution. These calibration steps can be performed through numerical signal processing, but require calibration information about the system that may require lengthy and complex measurement protocols. We report a highly robust calibration procedure that can simultaneously determine correction vectors for nonlinear wavenumber sampling and dispersion compensation. The proposed method requires only two simple mirror measurements and no prior knowledge about the system’s illumination source or detection scheme. This method applies to both spectral domain and swept-source OCT systems. Furthermore, it ...

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    3. Utility of Optical Coherence Tomography for Guiding Laser Therapy Among Patients With Recurrent Respiratory Papillomatosis

      Utility of Optical Coherence Tomography for Guiding Laser Therapy Among Patients With Recurrent Respiratory Papillomatosis

      Importance Recurrent respiratory papillomatosis (RRP) is a viral-induced disease caused by human papillomavirus and the second leading cause of dysphonia in children; however, neither a cure nor a definitive surgical treatment is currently available for RRP. Although laser therapy is often used in the treatment of RRP, the lack of real-time laser-tissue interaction feedback undermines the ability of physicians to provide treatments with low morbidity. Therefore, an intraoperative tool to monitor and control laser treatment depth is needed. Objective To investigate the potential of combining optical coherence tomography (OCT) with laser therapy for patient-tailored laryngeal RRP treatments. Design, Setting, and ...

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    4. Radiometric model for coaxial single- and multimode optical emission from double-clad fiber

      Radiometric model for coaxial single- and multimode optical emission from double-clad fiber

      Double-clad fibers (DCFs) are versatile waveguides supporting a single-mode core surrounded by a multimode inner cladding. DCFs are increasingly used for multimodal biomedical applications, such as imaging or therapy, for which the core is typically used for coherent illumination and the inner cladding, to support a concurrent modality. Proper optimization is, however, critical to ensure high optical performance and requires accurate modeling of coaxial single- and multimode output beams. In this paper, we present an approach based on geometrical optics and radiometry, which provides a simple and efficient modeling tool for designing and optimizing DCF-based systems. A radiometric definition of ...

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    5. Simultaneous multimodal ophthalmic imaging using swept-source spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography

      Simultaneous multimodal ophthalmic imaging using swept-source spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography

      Scanning laser ophthalmoscopy (SLO) benefits diagnostic imaging and therapeutic guidance by allowing for high-speed en face imaging of retinal structures. When combined with optical coherence tomography (OCT), SLO enables real-time aiming and retinal tracking and provides complementary information for post-acquisition volumetric co-registration, bulk motion compensation, and averaging. However, multimodality SLO-OCT systems generally require dedicated light sources, scanners, relay optics, detectors, and additional digitization and synchronization electronics, which increase system complexity. Here, we present a multimodal ophthalmic imaging system using swept-source spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography (SS-SESLO-OCT) for in vivo human retinal imaging. SESLO reduces the complexity ...

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    6. Combined optical coherence tomography and hyperspectral imaging using a double-clad fiber coupler

      Combined optical coherence tomography and hyperspectral imaging using a double-clad fiber coupler

      This work demonstrates the combination of optical coherence tomography (OCT) and hyperspectral imaging (HSI) using a double-clad optical fiber coupler. The single-mode core of the fiber is used for OCT imaging, while the inner cladding of the double-clad fiber provides an efficient way to capture the reflectance spectrum of the sample. The combination of both methods enables three-dimensional acquisition of the sample morphology with OCT, enhanced with complementary molecular information contained in the hyperspectral image. The HSI data can be used to highlight the presence of specific molecules with characteristic absorption peaks or to produce true color images overlaid on ...

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    7. Collagen Content Limits Optical Coherence Tomography Image Depth in Porcine Vocal Fold Tissue

      Collagen Content Limits Optical Coherence Tomography Image Depth in Porcine Vocal Fold Tissue

      Objective Vocal fold scarring, a condition defined by increased collagen content, is challenging to treat without a method of noninvasively assessing vocal fold structure in vivo. The goal of this study was to observe the effects of vocal fold collagen content on optical coherence tomography imaging to develop a quantifiable marker of disease. Study Design Excised specimen study. Setting Massachusetts Eye and Ear Infirmary. Subjects and Methods Porcine vocal folds were injected with collagenase to remove collagen from the lamina propria. Optical coherence tomography imaging was performed preinjection and at 0, 45, 90, and 180 minutes postinjection. Mean pixel intensity ...

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    8. Tri-modal microscope for head and neck tissue identification

      Tri-modal microscope for head and neck tissue identification

      A novel tri-modal microscope combining optical coherence tomography (OCT), spectrally encoded confocal microscopy (SECM) and fluorescence imaging is presented. This system aims at providing a tool for rapid identification of head and neck tissues during thyroid surgery. The development of a dual-wavelength polygon-based swept laser allows for synchronized, co-registered and simultaneous imaging with all three modalities. Further ameliorations towards miniaturization include a custom lens for optimal compromise between orthogonal imaging geometries as well as a double-clad fiber coupler for increased throughput. Image quality and co-registration is demonstrated on freshly excised swine head and neck tissue samples to illustrate the complementarity ...

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    9. Combined optical coherence tomography and hyper-spectral imaging using a double clad fiber coupler

      Combined optical coherence tomography and hyper-spectral imaging using a double clad fiber coupler

      This proceedings shows the combination of Optical Coherence Tomography (OCT) and Hyper-Spectral Imaging (HSI) using a double-clad optical fiber. The single mode core of the fiber is used to transmit OCT signals, while the cladding, with its large collection area, provides an efficient way to capture the reflectance spectrum of the sample. The combination of both methods enables three-dimensional acquisition of sample morphology with OCT, enhanced by the molecular information contained in its hyper-spectral image. We believe that the combination of these techniques could result in endoscopes with enhanced tissue identification capability

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    10. Towards in vivo laser coagulation and concurrent optical coherence tomography through double-clad fiber devices

      Towards in vivo laser coagulation and concurrent optical coherence tomography through double-clad fiber devices

      There is a strong clinical need for an optical coherence tomography (OCT) system capable of delivering concurrent coagulation light enabling image-guided dynamic laser marking for targeted collection of biopsies, as opposed to a random sampling, to reduce false-negative findings. Here, we present a system based on double-clad fiber (DCF) capable of delivering pulsed laser light through the inner cladding while performing OCT through the core. A previously clinically validated commercial OCT system (NVisionVLE, Ninepoint Medical) was adapted to enable in vivo esophageal image-guided dynamic laser marking. An optimized DCF coupler was implemented into the system to couple both modalities into ...

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    11. Multimodal ophthalmic imaging using swept source spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography

      Multimodal ophthalmic imaging using swept source spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography

      Scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) benefit clinical diagnostic imaging in ophthalmology by enabling in vivo noninvasive en face and volumetric visualization of retinal structures, respectively. Spectrally encoding methods enable confocal imaging through fiber optics and reduces system complexity. Previous applications in ophthalmic imaging include spectrally encoded confocal scanning laser ophthalmoscopy (SECSLO) and a combined SECSLO-OCT system for image guidance, tracking, and registration. However, spectrally encoded imaging suffers from speckle noise because each spectrally encoded channel is effectively monochromatic. Here, we demonstrate in vivo human retinal imaging using a swept source spectrally encoded scanning laser ophthalmoscope and ...

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    12. Intraoperative imaging of pediatric vocal fold lesions using optical coherence tomography

      Intraoperative imaging of pediatric vocal fold lesions using optical coherence tomography

      Optical coherence tomography (OCT) has been previously identified as a promising tool for exploring laryngeal pathologies in adults. Here, we present an OCT handheld probe dedicated to imaging the unique geometry involved in pediatric laryngoscopy. A vertical cavity surface emitting laser-based wavelength-swept OCT system operating at 60 frames per second was coupled to the probe to acquire three-dimensional (3-D) volumes in vivo . In order to evaluate the performance of the proposed probe and system, we imaged pediatric vocal fold lesions of patients going under direct laryngoscopy. Through this in vivo study, we extracted OCT features characterizing each pediatric vocal fold ...

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    13. Toward an automated method for optical coherence tomography characterization

      Toward an automated method for optical coherence tomography characterization

      With the increasing use of optical coherence tomography (OCT) in biomedical applications, robust yet simple methods for calibrating and benchmarking a system are needed. We present here a procedure based on a calibration object complemented with an algorithm that analyzes three-dimensional OCT datasets to retrieve key characteristics of an OCT system. The calibration object combines state-of-the-art tissue phantom material with a diamond-turned aluminum multisegment mirror. This method is capable of determining rapidly volumetric field-of-view, axial resolution, and image curvature. Moreover, as the phantom material mimics biological tissue, the system’s signal and noise levels can be evaluated in conditions close ...

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    14. Using attenuation coefficients from optical coherence tomography as markers of vocal fold maturation

      Using attenuation coefficients from optical coherence tomography as markers of vocal fold maturation

      Objectives/Hypothesis Optical coherence tomography (OCT) is a promising technology to noninvasively assess vocal fold microanatomy. The goal of this study was to develop a methodology using OCT to identify quantifiable markers of vocal fold development. Study Design In vivo study. Methods A two-step process was developed to reproducibly image the midmembranous vocal fold edge of 10 patients younger than 2 years and 10 patients between 11 and 16 years of age using OCT. An image analysis algorithm was implemented to extract OCT-derived A-lines for each patient. These A-lines were divided into three zones according to apparent changes in slope ...

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    15. Feature Of The Week 5/10/2015: Laser Tissue Coagulation and Concurrent Optical Coherence Tomography Through a Double-Clad Fiber Coupler

      Feature Of The Week 5/10/2015: Laser Tissue Coagulation and Concurrent Optical Coherence Tomography Through a Double-Clad Fiber Coupler

      This work is the result of a collaboration between researchers from Professor Caroline Boudoux’s team from Polytechnique Montréal (Canada) and Professor Brett E. Bouma’s team at the Wellman Center for Photomedicine (MGH, Boston). The goal is to assess whether OCT-guided biopsy could benefit from the use of double-clad fiber (DCF). DCF allows a single channel fiber-optic probe to be shared: i.e. the core propagating the OCT signal while the inner cladding delivers the coagulation laser light used for laser marking. DCF is herein used in conjunction with a double-clad fiber coupler (DCFC) to enable simultaneous and ...

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    16. Molecular imaging needles: dual-modality optical coherence tomography and fluorescence imaging of labeled antibodies deep in tissue

      Molecular imaging needles: dual-modality optical coherence tomography and fluorescence imaging of labeled antibodies deep in tissue

      Molecular imaging using optical techniques provides insight into disease at the cellular level. In this paper, we report on a novel dual-modality probe capable of performing molecular imaging by combining simultaneous three-dimensional optical coherence tomography (OCT) and two-dimensional fluorescence imaging in a hypodermic needle. The probe, referred to as a molecular imaging (MI) needle, may be inserted tens of millimeters into tissue. The MI needle utilizes double-clad fiber to carry both imaging modalities, and is interfaced to a 1310-nm OCT system and a fluorescence imaging subsystem using an asymmetrical double-clad fiber coupler customized to achieve high fluorescence collection efficiency. We ...

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    17. Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler

      Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler

      Double-clad fiber (DCF) is herein used in conjunction with a double-clad fiber coupler (DCFC) to enable simultaneous and co-registered optical coherence tomography (OCT) and laser tissue coagulation. The DCF allows a single channel fiber-optic probe to be shared: i.e. the core propagating the OCT signal while the inner cladding delivers the coagulation laser light. We herein present a novel DCFC designed and built to combine both signals within a DCF (>90% of single-mode transmission; >65% multimode coupling). Potential OCT imaging degradation mechanisms are also investigated and solutions to mitigate them are presented. The combined DCFC-based system was used to ...

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    18. Asymmetric double-clad fiber couplers for endoscopy

      Asymmetric double-clad fiber couplers for endoscopy

      We present an asymmetric double-clad fiber coupler (A-DCFC) exploiting a disparity in fiber etendues to exceed the equipartition limit ( ≤ 50 % extraction of inner cladding multi-mode light). The A-DCFC is fabricated using two commercially available fibers and a custom fusion-tapering setup to achieve > 70 % extraction of multi-mode inner cladding light without affecting ( > 95 % transmission) single-mode light propagation in the core. Imaging with the A-DCFC is demonstrated in a spectrally encoded imaging setup using a weakly backscattering biological sample. Other applications include the combination of optical coherence tomography with weak fluorescent or Raman scattering signals

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    19. Dual-modality needle probe for combined fluorescence imaging and three-dimensional optical coherence tomography

      Dual-modality needle probe for combined fluorescence imaging and three-dimensional optical coherence tomography

      To the best of our knowledge, we present the first needle probe for combined optical coherence tomography (OCT), and fluorescence imaging. The probe uses double-clad fiber (DCF) that guides the OCT signal and fluorescence excitation light in the core and collects and guides the returning fluorescence in the large-diameter multimode inner cladding. It is interfaced to a 1310 nm swept-source OCT system that has been modified to enable simultaneous 488 nm fluorescence excitation and > 500     nm emission detection by using a DCF coupler to extract the returning fluorescence signal in the inner cladding with high efficiency. We present imaging results ...

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    20. Quantitative Distinction of Unique Vocal Fold Subepithelial Architectures Using Optical Coherence Tomography

      Quantitative Distinction of Unique Vocal Fold Subepithelial Architectures Using Optical Coherence Tomography

      Objectives : The primary objective of this study was to quantitatively analyze ex vivo porcine, fetal human, and adult human vocal folds by use of optical coherence tomography (OCT). A secondary objective was to quantitatively discriminate among 1-, 2-, and 3-layer lamina propria structures. Methods : We performed an analysis of the vocal folds of 10 adult pig, 3 adult human, and 2 fetal human vocal fold specimens using OCT and histologic techniques. We present a quantitative comparison of the OCT results and histologic findings. Results : We found that OCT allowed for the visualization of the subepithelial vocal fold architecture of all ...

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    21. Feature Of The Week 5/13/12: Polytechnique Montreal Researchers Investigate the Use of Optical Coherence Tomography for Guiding Treatment of Musculoskeletal Diseases such as Scoliosis

      Feature Of The Week 5/13/12: Polytechnique Montreal Researchers Investigate the Use of Optical Coherence Tomography for Guiding Treatment of Musculoskeletal Diseases such as Scoliosis

      Researchers from the Polytechnique Montreal University develop an experimental intra-operative optical coherence tomography based endoscope imaging system to precisely guide the insertion of hemi-staples that are are inserted on the growth plate to locally control vertebral growth to treat adolescent idopathic scoliosis.  Below is a summary of their work.Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine requiring in severe cases invasive surgery. Here, we explore the potential of optical coherence tomography (OCT) as a guiding tool for novel fusionless minimally invasive spinal surgeries on an ex vivo porcine model. We show that OCT, despite its ...

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    22. Optical coherence tomography for the identification of musculoskeletal structures of the spine: a pilot study

      Optical coherence tomography for the identification of musculoskeletal structures of the spine: a pilot study

      Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine requiring in severe cases invasive surgery. Here, we explore the potential of optical coherence tomography (OCT) as a guiding tool for novel fusionless minimally invasive spinal surgeries on an ex vivo porcine model. We show that OCT, despite its limited penetration depth, may be used to precisely locate structures such as growth plate, bone and intervertebral disk using relative attenuation coefficients. We further demonstrate a segmentation algorithm that locates growth plates automatically on en-face OCT reconstructions

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    23. High-velocity-flow imaging with real-time Doppler optical coherence tomography

      High-velocity-flow imaging with real-time Doppler optical coherence tomography
      We present a real-time time-domain Doppler optical coherence tomography (OCT) system based on the zero-crossing method for velocity measurements of fluid flows with attainable velocities up to 10 m/s. In the current implementation, one-dimensional and two-dimensional velocity profiles of fluid flows ranging from 1 cm/s to more than 3 m/s were obtained for both laminar and turbulent flows. The line rate was approximately 500 Hz, and the images were treated in real time. This approach has the advantage of providing reliable velocity maps free from phase aliasing or other artifacts common to several OCT systems. The system ...
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    24. Combined Reflection Confocal Microscopy and Optical Coherence Tomography Imaging of Esophageal Biopsy

      Reflection confocal microscopy (RCM) and optical coherence tomography (OCT) are two non-contact optical imaging technologies that provide images of tissue cellular and architectural morphology, which are both used for histopathologic diagnosis. We have developed a combined RCM and OCT system to compare the accuracy of these imaging techniques for diagnosing esophageal pathology and to evaluate the potential utility of merging the two modalities into a single imaging system. Clinical study was conducted on 32 human esophageal biopsy samples from 23 patients with various histories. Esophageal mucosa was differentiated from gastric mucosa, Barrett's esophagus with intestinal metaplasia was distinguished from ...
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    1-24 of 24
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    1. (21 articles) Caroline Boudoux
    2. (20 articles) Polytechnique Montreal
    3. (10 articles) Harvard University
    4. (8 articles) Kathy Beaudette
    5. (5 articles) Massachusetts Eye and Ear Infirmary
    6. (5 articles) Massachusetts General Hospital
    7. (5 articles) Brett E. Bouma
    8. (3 articles) Martin L. Villiger
    9. (2 articles) Massachusetts Institute of Technology
    10. (2 articles) Andrew M. Rollins
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    16. (1 articles) Colin Hopper
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    High-velocity-flow imaging with real-time Doppler optical coherence tomography Optical coherence tomography for the identification of musculoskeletal structures of the spine: a pilot study Feature Of The Week 5/13/12: Polytechnique Montreal Researchers Investigate the Use of Optical Coherence Tomography for Guiding Treatment of Musculoskeletal Diseases such as Scoliosis Quantitative Distinction of Unique Vocal Fold Subepithelial Architectures Using Optical Coherence Tomography Dual-modality needle probe for combined fluorescence imaging and three-dimensional optical coherence tomography Asymmetric double-clad fiber couplers for endoscopy Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler Molecular imaging needles: dual-modality optical coherence tomography and fluorescence imaging of labeled antibodies deep in tissue Feature Of The Week 5/10/2015: Laser Tissue Coagulation and Concurrent Optical Coherence Tomography Through a Double-Clad Fiber Coupler Remote scanning for ultra-large field of view in wide-field microscopy and full-field OCT Inadequate Intimal Angiogenesis as a Source of Coronary Plaque Instability Comparison of optical coherence tomography angiography results of adult patients with Familial Mediterranean fever and healthy individuals