1. Articles from Claude Boccara

    1-21 of 21
    1. Probing dynamic processes in the eye at multiple spatial and temporal scales with multimodal full field OCT

      Probing dynamic processes in the eye at multiple spatial and temporal scales with multimodal full field OCT

      We describe recent technological progress in multimodal en face full-field optical coherence tomography that has allowed detection of slow and fast dynamic processes in the eye. We show that by combining static, dynamic and fluorescence contrasts we can achieve label-free high-resolution imaging of the retina and anterior eye with temporal resolution from milliseconds to several hours, allowing us to probe biological activity at subcellular scales inside 3D bulk tissue. Our setups combine high lateral resolution over a large field of view with acquisition at several hundreds of frames per second which make it a promising tool for clinical applications and ...

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    2. The clinical usefulness of optical coherence tomography during cancer interventions

      The clinical usefulness of optical coherence tomography during cancer interventions

      Introduction Tumor detection and visualization plays a key role in the clinical workflow of a patient with suspected cancer, both in the diagnosis and treatment. Several optical imaging techniques have been evaluated for guidance during oncological interventions. Optical coherence tomography (OCT) is a technique which has been widely evaluated during the past decades. This review aims to determine the clinical usefulness of OCT during cancer interventions focussing on qualitative features, quantitative features and the diagnostic value of OCT. Methods A systematic literature search was performed for articles published before May 2018 using OCT in the field of surgical oncology. Based ...

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    3. In vivo imaging through the entire thickness of human cornea by full-field optical coherence tomography

      In vivo imaging through the entire thickness of human cornea by full-field optical coherence tomography

      Despite obvious improvements in visualization of the in vivo cornea through the faster imaging speeds and higher axial resolutions, cellular imaging stays unresolvable task for OCT, as en face viewing with a high lateral resolution is required. The latter is possible with FFOCT, a method that relies on a camera, moderate numerical aperture (NA) objectives and an incoherent light source to provide en face images with a micrometer-level resolution. Recently, we for the first time demonstrated the ability of FFOCT to capture images from the in vivo human cornea1. In the current paper we present an extensive study of appearance ...

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    4. Cell Motility as Contrast Agent in Retinal Explant Imaging With Full-Field Optical Coherence Tomography

      Cell Motility as Contrast Agent in Retinal Explant Imaging With Full-Field Optical Coherence Tomography

      Purpose : To use cell motility as a contrast agent in retinal explants. Methods : Macaque and mouse retinal explants were imaged with high resolution full field optical coherence tomography (FFOCT) and dynamic FFOCT, coupled with fluorescence imaging. Results : Static and dynamic FFOCT create complementary contrast from different structures within a cell. When imaging in vitro samples, static FFOCT detects steep refractive index gradients to reveal stationary structures including fibers, vessels, collagen, and cell contours, while dynamic FFOCT emphasizes metabolic activity of moving structures that are mainly intracellular, thus creating or enhancing contrast in cells that were previously hidden in noise. Dynamic ...

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    5. Full-Field Optical Coherence Tomography as a Diagnosis Tool: Recent Progress with Multimodal Imaging

      Full-Field Optical Coherence Tomography as a Diagnosis Tool: Recent Progress with Multimodal Imaging

      Full-field optical coherence tomography (FF-OCT) is a variant of OCT that is able to register 2D en face views of scattering samples at a given depth. Thanks to its superior resolution, it can quickly reveal information similar to histology without the need to physically section the sample. Sensitivity and specificity levels of diagnosis performed with FF-OCT are 80% to 95% of the equivalent histological diagnosis performances and could therefore benefit from improvement. Therefore, multimodal systems have been designed to increase the diagnostic performance of FF-OCT. In this paper, we will discuss which contrasts can be measured with such multimodal systems ...

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    6. Dynamic multimodal full-field optical coherence tomography and fluorescence structured illumination microscopy

      Dynamic multimodal full-field optical coherence tomography and fluorescence structured illumination microscopy

      We report on the development of a configuration of a multimodal full-field optical coherence tomography (FF-OCT) and fluorescence microscope. Our system can simultaneously acquire FF-OCT and structured illumination microscopy images. Dynamic parallel evolution of tissue microstructures and biochemical environments can be visualized. We use high numerical aperture objectives to optimize the combination of the two modalities. We imaged the propagation of mechanical waves initiated by calcium waves in a heart wall to illustrate the interest of simultaneous recording of mechanical and biochemical information.

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    7. Diffuse shear wave imaging: toward passive elastography using low-frame rate spectral-domain optical coherence tomography

      Diffuse shear wave imaging: toward passive elastography using low-frame rate spectral-domain optical coherence tomography

      Optical coherence tomography (OCT) can map the stiffness of biological tissue by imaging mechanical perturbations (shear waves) propagating in the tissue. Most shear wave elastography (SWE) techniques rely on active shear sources to generate controlled displacements that are tracked at ultrafast imaging rates. Here, we propose a noise-correlation approach to retrieve stiffness information from the imaging of diffuse displacement fields using low-frame rate spectral-domain OCT. We demonstrated the method on tissue-mimicking phantoms and validated the results by comparison with classic ultrafast SWE. Then we investigated the in vivo feasibility on the eye of an anesthetized rat by applying noise correlation ...

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    8. High-resolution handheld rigid endomicroscope based on full-field optical coherence tomography

      High-resolution handheld rigid endomicroscope based on full-field optical coherence tomography

      Full-field optical coherence tomography (FF-OCT) is a powerful tool for nondestructive assessment of biological tissue, i.e., for the structural examination of tissue in depth at a cellular resolution. Mostly known as a microscopy device for ex vivo analysis, FF-OCT has also been adapted to endoscopy setups since it shows good potential for in situ cancer diagnosis and biopsy guidance. Nevertheless, all the attempts to perform endoscopic FF-OCT imaging did not go beyond lab setups. We describe here, to the best of our knowledge, the first handheld FF-OCT endoscope based on a tandem interferometry assembly using incoherent illumination. A common-path ...

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    9. Rapid evaluation of fresh ex vivo kidney tissue with full-field optical coherence tomography

      Rapid evaluation of fresh ex vivo kidney tissue with full-field optical coherence tomography

      Background: Full-field optical coherence tomography (FFOCT) is a real-time imaging technique that rapidly generates images reminiscent of histology without any tissue processing, warranting its exploration for evaluation of ex vivo kidney tissue. Methods: Fresh tissue sections from tumor and adjacent nonneoplastic kidney ( n = 25 nephrectomy specimens; clear cell renal cell carcinoma (CCRCC) = 12, papillary RCC (PRCC) = 4, chromophobe RCC (ChRCC) = 4, papillary urothelial carcinoma (PUC) = 1, angiomyolipoma (AML) = 2 and cystic nephroma = 2) were imaged with a commercial FFOCT device. Sections were submitted for routine histopathological diagnosis. Results: Glomeruli, tubules, interstitium, and blood vessels were identified in nonneoplastic tissue. In ...

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    10. Assessment of Sentinel Node Biopsies With Full-Field Optical Coherence Tomography

      Assessment of Sentinel Node Biopsies With Full-Field Optical Coherence Tomography

      Current techniques for the intraoperative analysis of sentinel lymph nodes during breast cancer surgery present drawbacks such as time and tissue consumption. Full-field optical coherence tomography is a novel noninvasive, high-resolution, fast imaging technique. This study investigated the use of full-field optical coherence tomography as an alternative technique for the intraoperative analysis of sentinel lymph nodes. Seventy-one axillary lymph nodes from 38 patients at Tenon Hospital were imaged minutes after excision with full-field optical coherence tomography in the pathology laboratory, before being handled for histological analysis. A pathologist performed a blind diagnosis (benign/malignant), based on the full-field optical coherence ...

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    11. Anisotropic polyvinyl alcohol hydrogel phantom for shear wave elastography in fibrous biological soft tissue: a multimodality characterization

      Anisotropic polyvinyl alcohol hydrogel phantom for shear wave elastography in fibrous biological soft tissue: a multimodality characterization

      Shear wave elastography imaging techniques provide quantitative measurement of soft tissues elastic properties. Tendons, muscles and cerebral tissues are composed of fibers, which induce a strong anisotropic effect on the mechanical behavior. Currently, these tissues cannot be accurately represented by existing elastography phantoms. Recently, a novel approach for orthotropic hydrogel mimicking soft tissues has been developed (Millon et al 2006 J. Biomed. Mater. Res. B 305–11). The mechanical anisotropy is induced in a polyvinyl alcohol (PVA) cryogel by stretching the physical crosslinks of the polymeric chains while undergoing freeze/thaw cycles. In the present study we propose an original ...

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    12. Feature Of The Week: Feature Of The Week 1/26/14: ESPCI-ParisTech Investigates Full-Field Optical Coherence Tomograpy (FF-OCT) Shear Wave Elastography

      Feature Of The Week: Feature Of The Week 1/26/14: ESPCI-ParisTech Investigates Full-Field Optical Coherence Tomograpy (FF-OCT) Shear Wave Elastography

      Elasticity maps of tissue have proved to be particularly useful in providing complementary contrast to ultrasonic imaging, e.g., for cancer diagnosis at the millimeter scale. Optical coherence tomography (OCT) offers an endogenous contrast based on singly backscattered optical waves. Adding complementary contrast to OCT images by recording elasticity maps could also be valuable in improving OCT-based diagnosis at the microscopic scale. Static elastography has been successfully coupled with full-field OCT (FF-OCT) in order to realize both micrometer-scale sectioning and elasticity maps. Nevertheless, static elastography presents a number of drawbacks, mainly when stiffness quantification is required. Here, we describe the ...

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    13. Full-field optical coherence tomography for the analysis of fresh unstained human lobectomy specimens

      Full-field optical coherence tomography for the analysis of fresh unstained human lobectomy specimens

      Full-field optical coherence tomography (FFOCT) is a real-time imaging technique that generates high-resolution three-dimensional tomographic images from unprocessed and unstained tissues. Lack of tissue processing and associated artifacts, along with the ability to generate large-field images quickly, warrants its exploration as an alternative diagnostic tool. Materials and Methods: One section each from the tumor and from adjacent non-neoplastic tissue was collected from 13 human lobectomy specimens. They were imaged fresh with FFOCT and then submitted for routine histopathology. Two blinded pathologists independently rendered diagnoses based on FFOCT images. Results: Normal lung architecture (alveoli, bronchi, pleura and blood vessels) was readily ...

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    14. Full-field OCT: a non-invasive tool for diagnosis and tissue selection

      Full-field OCT: a non-invasive tool for diagnosis and tissue selection

      Full-field optical coherence tomography (FFOCT) enables in-depth, high-resolution tissue imaging at the cellular level. Pathologists using the technology achieve high sensitivity scores, offering possible future improvements in healthcare quality and decreases in costs, especially for cancer care.

      Optical coherence tomography (OCT), on which the technique is based, undertakes interferometric selection of singly backscattered photons using superposition of waves to decipher their characteristics). It is a powerful technique for imaging biological tissues, particularly for eye examination.1 FFOCT, in contrast with most OCT approaches (time domain- or Fourier domain OCT, for example), directly takes 2D ‘ en face' images using megapixel cameras ...

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    15. Imaging of non-tumorous and tumorous human brain tissues with full-field optical coherence tomography

      Imaging of non-tumorous and tumorous human brain tissues with full-field optical coherence tomography

      A prospective study was performed on neurosurgical samples from 18 patients to evaluate the use of full-field optical coherence tomography (FF-OCT) in brain tumor diagnosis. FF-OCT captures en face slices of tissue samples at 1 μm resolution in 3D to a penetration depth of around 200 μm. A 1 cm 2 specimen is scanned at a single depth and processed in about 5 min. This rapid imaging process is non-invasive and requires neither contrast agent injection nor tissue preparation, which makes it particularly well suited to medical imaging applications. Temporal chronic epileptic parenchyma and brain tumors such as meningiomas, low-grade ...

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    16. Large Field, High Resolution Full-Field Optical Coherence Tomography: A Pre-clinical Study of Human Breast Tissue and Cancer Assessment

      Large Field, High Resolution Full-Field Optical Coherence Tomography: A Pre-clinical Study of Human Breast Tissue and Cancer Assessment

      We present a benchmark pilot study in which high-resolution Full-Field Optical Coherence Tomography (FF-OCT) was used to image human breast tissue and is evaluated to assess its ability to aid the pathologist’s management of intra-operative diagnoses. FF-OCT imaging safety was investigated and agreement between FF-OCT and routinely prepared histopathological images was evaluated. The compact setup used for this study provides 1 mm3 resolution and 200 mm imaging depth, and a 2.25 cm2 specimen is scanned in about 7 minutes. 75 breast specimens were imaged from 22 patients (21 women, 1 man) with a mean age of 58 (range ...

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    17. Imaging of non tumorous and tumorous human brain tissue with full-field optical coherence tomography

      Imaging of non tumorous and tumorous human brain tissue with full-field optical coherence tomography

      A prospective study was performed on neurosurgical samples from 18 patients to evaluate the use of Full-Field Optical Coherence Tomography (FF-OCT) in brain tumor diagnosis. FF-OCT captures en face slices of tissue samples at 1μm resolution in 3D with a typical 200μm imaging depth. A 1cm² specimen is scanned at a single depth and processed in about 5 minutes. This rapid imaging process is non-invasive and requires neither contrast agent injection nor tissue preparation, 30 which makes it particularly well suited to medical imaging applications. Temporal chronic epileptic parenchyma and brain tumors such as meningiomas, lowgrade and high-grade ...

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    18. Feature Of The Week 11/27/11: Langevin Institute and LLTech Investigate In Vivo Cellular Full-Field OCT Imaging with a Rigid Endoscopic Probe

      Feature Of The Week 11/27/11: Langevin Institute and LLTech Investigate In Vivo Cellular Full-Field OCT Imaging with a Rigid Endoscopic Probe

      Full-Field OCT (FFOCT) is a particular approach of OCT that directly takes “en face” 2-D images with an isotropic resolution around 1µm [1]. With such a high resolution FFOCT systems can produce images that are similar to that obtained with classical histology procedures and can thus be important tools for pathology [2]. This is why we want to combine the interest of a setup with a needle probe with the performances of FFOCT.A FFOCT system with probe has to address the problem of keeping the performances of FFOCT in a setup using a miniaturized, medically safe probe. As proposed ...

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    19. Brain refractive index measured in vivo with high-NA defocus-corrected full-field OCT and consequences for two-photon microscopy

      Brain refractive index measured in vivo with high-NA defocus-corrected full-field OCT and consequences for two-photon microscopy
      Two-photon laser scanning microscopy (2PLSM) is an important tool for in vivo tissue imaging with sub-cellular resolution, but the penetration depth of current systems is potentially limited by sample-induced optical aberrations. To quantify these, we measured the refractive index n' in the somatosensory cortex of 7 rats in vivo using defocus optimization in full-field optical coherence tomography (ff-OCT). We found n' to be independent of imaging depth or rat age. From these measurements, we calculated that two-photon imaging beyond 200µm into the cortex is limited by spherical aberration, indicating that adaptive optics will improve imaging depth.
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    20. Spectroscopic ultrahigh-resolution full-field optical coherence microscopy

      Spectroscopic ultrahigh-resolution full-field optical coherence microscopy
      Arnaud Dubois, Julien Moreau, Claude Boccara We have developed a full-field optical coherence microscopy system providing intensity-based tomographic images and spectroscopic information with ultrahigh spatial resolution. Local measurements of the backscattered light spectrum center of mass are achieved through short-time Fourier analysis of ... [Opt. Express 16, 17082-17091 (2008)]
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    21. Optical 3D-storage in sol-gel materials with a reading by Optical Coherence Tomography-technique

      We report on the recording of 3D optical memories in sol-gel materials by using a non-linear absorption effect. This effect induces a local change of the optical properties of the material which is read and quantified with a high resolution full-field Optical Coherence Tomography setup. It is the first time that this technique is used for this purpose. Data recording was performed by focused picosecond (ps) single-pulse irradiation at 1064 nm with energy densities of 10 and 33 J/cm2 per pulse.
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    1-21 of 21
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    1. (21 articles) Claude Boccara
    2. (17 articles) ESPCI ParisTech
    3. (12 articles) LLTech
    4. (7 articles) Mathias Fink
    5. (7 articles) Kate Grieve
    6. (6 articles) Fabrice Harms
    7. (5 articles) LLTech Light-CT Scanner
    8. (4 articles) Osnath Assayag
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    Spectroscopic ultrahigh-resolution full-field optical coherence microscopy Brain refractive index measured in vivo with high-NA defocus-corrected full-field OCT and consequences for two-photon microscopy Feature Of The Week 11/27/11: Langevin Institute and LLTech Investigate In Vivo Cellular Full-Field OCT Imaging with a Rigid Endoscopic Probe Imaging of non tumorous and tumorous human brain tissue with full-field optical coherence tomography Large Field, High Resolution Full-Field Optical Coherence Tomography: A Pre-clinical Study of Human Breast Tissue and Cancer Assessment Imaging of non-tumorous and tumorous human brain tissues with full-field optical coherence tomography Full-field OCT: a non-invasive tool for diagnosis and tissue selection Full-field optical coherence tomography for the analysis of fresh unstained human lobectomy specimens Feature Of The Week: Feature Of The Week 1/26/14: ESPCI-ParisTech Investigates Full-Field Optical Coherence Tomograpy (FF-OCT) Shear Wave Elastography Optical coherence tomography angiography of foveal neovascularisation in proliferative diabetic retinopathy Treating port wine stain birthmarks using dynamic optical coherence tomography-guided setting Repeatability of quantitative measurements of retinal layers with SD-OCT and agreement between vertical and horizontal scan protocols in healthy eyes