1. 1-24 of 832 1 2 3 4 ... 33 34 35 »
    1. Findings of OCT‐angiography compared to fluorescein and indocyanine green angiography in central serous chorioretinopathy

      Findings of OCT‐angiography compared to fluorescein and indocyanine green angiography in central serous chorioretinopathy

      Purpose The present study analyzed the appearances of optical coherence tomography angiography (OCTA) in patients with central serous chorioretinopathy (CSC) based on fluorescein angiography (FA) and indocyanine green angiography (ICGA). Method In the current case series, 54 eyes of 50 patients diagnosed as CSC were evaluated retrospectively. OCTA, FA, and ICGA were performed on each patient. Two trained observers examined the OCTA images independently to confirm and compare the choriocapillary appearance with that on FA/ICGA. Also, the leakage of vessels on FA, perfusion of choroidal blood flow on ICGA, blood flow density, and vascular morphology on OCTA, as well ...

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    2. Automated three‐dimensional cell counting method for grading uveitis of rodent eye in vivo with optical coherence tomography

      Automated three‐dimensional cell counting method for grading uveitis of rodent eye in vivo with optical coherence tomography

      In preclinical vision research, cell grading in small animal models is essential for the quantitative evaluation of intraocular inflammation. Here, we present a new and practical optical coherence tomography (OCT) image analysis method for the automated detection and counting of aqueous cells in the anterior chamber (AC) of a rodent model of uveitis. Anterior segment OCT images are acquired with a 100 kHz swept‐source OCT system. The proposed method consists of 2 steps. In the first step, we first despeckle and binarize each OCT image. After removing AS structures in the binary image, we then apply area thresholding to ...

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    3. Quantitative evaluation of optical coherence tomography angiography images of diabetic retinopathy eyes before and after removal of projection artifacts

      Quantitative evaluation of optical coherence tomography angiography images of diabetic retinopathy eyes before and after removal of projection artifacts

      Projection artifacts (PAs) affect the quantification of vascular parameters in the deep layer optical coherence tomography (OCT) angiography image. This study eliminated PA and quantified its effect on imaging. 53 eyes (30 subjects) of normal Indian subjects and 113 eyes (92 patients) of type 2 diabetes mellitus with retinopathy (DR) underwent imaging with a scan area of 3 mm × 3 mm. In this study, a normalized cross‐correlation between superficial and deep layer was used to remove PA in deep layer. Local fractal analysis was done to compute vascular parameters such as foveal avascular zone area (mm 2 ), vessel density ...

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    4. Multiple enface image averaging for enhanced optical coherence tomography angiography imaging

      Multiple enface image averaging for enhanced optical coherence tomography angiography imaging

      Purpose To investigate the effect of multiple enface image averaging on image quality of the optical coherence tomography angiography (OCTA). Methods Twenty‐one normal volunteers were enrolled in this study. For each subject, one eye was imaged with 3 × 3 mm scan protocol, and another eye was imaged with the 6 × 6 mm scan protocol centred on the fovea using the ZEISS Angioplex™ spectral‐domain OCTA device. Eyes were repeatedly imaged to obtain nine OCTA cube scan sets, and nine superficial capillary plexus (SCP) and deep capillary plexus (DCP) were individually averaged after registration. Results Eighteen eyes with a 3 ...

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    5. Mechanical spectroscopy and imaging of skin components in vivo: Assignment of the observed moduli

      Mechanical spectroscopy and imaging of skin components in vivo: Assignment of the observed moduli

      Background The need to quantitatively identify the composition and organization of the macromolecular components of skin, skin lesions, scars, tumors, extracellular matrices (ECMs), and wound tissue has been a goal of researchers for many decades. A variety of studies have been recently reported applying optical coherence tomography (OCT) to image skin and cutaneous lesions. Materials and Methods This article describes the use of vibrational OCT to image and noninvasively characterize the macromolecular components of the ECM of skin. Results We report that the major macromolecular components of skin and scar can be identified noninvasively by their characteristic moduli calculated from ...

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    6. OCT‐based angiography of human dermal microvascular reactions to local stimuli: Implications for increasing capillary blood collection volumes

      OCT‐based angiography of human dermal microvascular reactions to local stimuli: Implications for increasing capillary blood collection volumes

      Objectives To measure and compare microvascular responses within the skin of the upper arm to local stimuli, such as heating or rubbing, through the use of optical coherence tomography angiography (OCTA), and to investigate its impact on blood volume collection. Materials and Methods With the use of heat packs or rubbing, local stimulation was applied to the skin of either the left or right upper arm. Data from the stimulated sites were obtained using OCTA comparing pre‐ and post‐stimulation microvascular parameters, such as vessel density, mean vessel diameter, and mean avascular pore size. Additionally, blood was collected using a ...

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    7. Functional optical coherence tomography of neurovascular coupling interactions in the retina

      Functional optical coherence tomography of neurovascular coupling interactions in the retina

      Quantitative evaluation of retinal neurovascular coupling is essential for a better understanding of visual function and early detection of eye diseases. However, there is no established method to monitor coherent interactions between stimulus‐evoked neural activity and hemodynamic responses at high resolution. Here we report a multi‐modal functional optical coherence tomography (OCT) imaging methodology to enable concurrent intrinsic optical signal (IOS) imaging of stimulus‐evoked neural activity and hemodynamic responses at capillary resolution. OCT angiography guided IOS analysis was used to separate neural‐IOS and hemodynamic‐IOS changes in the same retinal image sequence. Frequency flicker stimuli evoked neural ...

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      Mentions: Xincheng Yao
    8. Clinical impact of optical coherence tomography findings on culprit plaque in acute coronary syndrome: The OCT‐FORMIDABLE study registry

      Clinical impact of optical coherence tomography findings on culprit plaque in acute coronary syndrome: The OCT‐FORMIDABLE study registry

      Background Aim of this study was to evaluate the clinical impact of the culprit plaque features assessed by optical coherence tomography (OCT) in patients with acute coronary syndrome (ACS). Methods The OCT‐FORMIDABLE register enrolled retrospectively all consecutive patients who perform OCT on culprit plaque in patients with ACS in nine European centres. The primary endpoint was the prevalence of culprit plaque rupture (CPR) in patients experiencing major adverse cardiovascular events (MACEs). Secondary endpoint was the prevalence necrotic core with macrophage infiltrations (NCMI) in the patients experiencing MACEs. Results Two‐hundred and nine patients were included in the study. Mean ...

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    9. Pseudo‐Kaposi sarcoma: report of a case investigated by dermoscopy, reflectance confocal microscopy and optical coherence tomography

      Pseudo‐Kaposi sarcoma: report of a case investigated by dermoscopy, reflectance confocal microscopy and optical coherence tomography

      Letter to the editor. First described in 1965 by Mali et al., pseudo‐Kaposi sarcoma (PKS), also known as acroangiodermatitis, is a rare disease inscribed in the setting of cutaneous reactive angiomatoses (CRAs). CRA are all characterized by occlusion and/or inflammation of cutaneous vessels, followed by histiocyte recruitment and endotheliocyte and pericyte hyperplasia. As the name suggests, PKS nearly resembles Kaposi sarcoma, but is benign in its nature. PKS typically presents with violaceous papules and plaques, usually located on the inferior limbs.

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    10. Dynamic optical coherence tomography of histamine induced wheals

      Dynamic optical coherence tomography of histamine induced wheals

      Background Dynamic optical coherence tomography (D‐OCT) is a noninvasive imaging technique providing images of the skin and detecting movement in the tissue ie, measuring blood flow. The “attenuation coefficient” describes light absorption and scattering abilities of the tissue, while the dynamic signal provides a quantitative measure of the blood flow. Aim The study objective is to describe the dynamic changes of the skin and skin vessels during histamine release using D‐OCT. Methods Healthy volunteers had local histamine injections in the skin and D‐OCT‐scans performed at 2‐minute intervals to detect changes in blood flow, attenuation and ...

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    11. In situ biofilm quantification in Bioelectrochemical Systems using Optical Coherence Tomography

      In situ biofilm quantification in Bioelectrochemical Systems using Optical Coherence Tomography

      Detailed studying of microbial growth in bioelectrochemical systems is required for their proper design and operation. Here we report on the use of Optical Coherence Tomography (OCT) as a tool for in situ and non‐invasive quantification of biofilm growth on electrodes (bioanodes). An experimental platform is designed and described in which transparent electrodes are used to allow for real‐time, three‐dimensional biofilm imaging. The accuracy and precision of the developed method is assessed by relating OCT results to well‐established standards for biofilm quantification (COD and Total N) and show high correspondence to these standards. Biofilm thickness as ...

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    12. The use of intensity‐based Doppler variance method for single vessel response to functional neurovascular activation

      The use of intensity‐based Doppler variance method for single vessel response to functional neurovascular activation

      This study presents one use of optical coherence tomography angiography (OCT) technique to examine neurovascular coupling effect. Repeated B‐scans OCT recording is performed on the rat somatosensory cortex with cranial window preparation while its contra‐lateral forepaw is electrically stimulated to activate the neurons in rest. We use an intensity‐based Doppler variance (IBDV) algorithm mapped cerebral blood vessels in the cortex, and the temporal alteration in blood perfusion during neurovascular activation is analyzed using the proposed IBDV quantitative parameters. By using principal component analysis (PCA)‐based Fuzzy C Means clustering method, the stimulus‐evoked vasomotion patterns were classified ...

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    13. Visualization of corneal vascularization in peripheral hypertrophic subepithelial corneal opacification with OCT angiography

      Visualization of corneal vascularization in peripheral hypertrophic subepithelial corneal opacification with OCT angiography

      Purpose The major goal of this study was to test the hypothesis that in patients with peripheral hypertrophic subepithelial corneal opacification (PHSCO), visualization of corneal vessels is better with optical coherence tomography angiography (OCTA) than with conventional slit lamp microphotography. Methods Patients with PHSCO were included in this prospective study. The corneal findings were photographed using a slit lamp camera (Haag Streit BM 900 ® ) and visualized with anterior‐segment OCT (Optovue XR Avanti, Fremont, California, USA). Additionally, OCTA with the Angiovue Imaging™ System was performed in the area of PHSCO. Results Thirty‐four eyes of 19 patients (26% male and ...

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      Mentions: Optovue Haag-Streit
    14. Spectrally encoded coherence tomography and reflectometry: Simultaneous en face and cross‐sectional imaging at 2 gigapixels per second

      Spectrally encoded coherence tomography and reflectometry: Simultaneous en face and cross‐sectional imaging at 2 gigapixels per second

      Non‐invasive biological imaging is crucial for understanding in vivo structure and function. Optical coherence tomography (OCT) and reflectance confocal microscopy are two of the most widely used optical modalities for exogenous contrast‐free, high‐resolution, three‐dimensional imaging in non‐fluorescent scattering tissues. However, sample motion remains a critical barrier to raster‐scanned acquisition and reconstruction of wide‐field anatomically accurate volumetric datasets. We introduce spectrally encoded coherence tomography and reflectometry (SECTR), a high‐speed, multimodality system for simultaneous OCT and spectrally encoded reflectance (SER) imaging. SECTR utilizes a robust system design consisting of shared optical relays, scanning mirrors ...

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    15. Cerebral capillary flow imaging by wavelength‐division‐multiplexing swept‐source optical Doppler tomography

      Cerebral capillary flow imaging by wavelength‐division‐multiplexing swept‐source optical Doppler tomography

      Swept‐source optical coherence tomography has demonstrated the unique advantages for fast imaging rate and long imaging distance, however, limited axial resolution and complex phase noises restrict swept‐source optical coherence Doppler tomography (SS‐ODT) for quantitative capillary blood flow imaging in the deep cortices. Here, the wavelength‐division‐multiplexing optical Doppler tomography (WDM‐ODT) method, which divides a single interferogram into multiple phase‐correlated interferograms, is proposed to effectively enhance the sensitivity for cerebral capillary flow imaging. Both flow phantom and in vivo mouse brain imaging studies show that WDM‐ODT is able to significantly suppress background phase noise ...

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    16. Two optical coherence tomography systems detect topical gold nanoshells in hair follicles, sweat ducts and measure epidermis

      Two optical coherence tomography systems detect topical gold nanoshells in hair follicles, sweat ducts and measure epidermis

      Optical coherence tomography (OCT) is an optical imaging technology that enables real time, high‐resolution, cross‐sectional and en face investigation of skin by detecting reflected broad‐spectrum near‐infrared light from tissue. OCT provides micron‐scale spatial resolution and millimeter‐scale depth of penetration [1]. Several commercial OCT systems with handheld probes targeted for Dermatology are now available [2].

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    17. Three‐months optical coherence tomography analysis of a biodegradable polymer, sirolimus‐eluting stent

      Three‐months optical coherence tomography analysis of a biodegradable polymer, sirolimus‐eluting stent

      Objective We aimed to assess early neointimal healing by optical coherence tomography (OCT) 3 months after implantation of the ultrathin Orsiro® sirolimus‐eluting stent with biodegradable polymer. Background New generations of drug‐eluting stents with biodegradable polymer have been developed to avoid the continued vascular irritation of durable polymers. Methods In this prospective, open‐label study, 34 patients received an Orsiro® sirolimus‐eluting stent with biodegradable polymer. In a subgroup of patients ( n  = 15), the intervention was performed under OCT guidance. All patients underwent OCT‐examination at three months. The primary endpoint was 3‐month neointimal healing (NIH) score, calculated ...

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    18. Evaluating glaucomatous abnormality in peripapillary optical coherence tomography enface visualisation of the retinal nerve fibre layer reflectance

      Evaluating glaucomatous abnormality in peripapillary optical coherence tomography enface visualisation of the retinal nerve fibre layer reflectance

      Purpose Optical coherence tomography (OCT) enface visualisation of the retinal nerve fibre layer (RNFL) reflectance has been found to have some advantages over retinal thickness measures. However, it is not yet clear how abnormalities on enface images relate to findings of abnormalities from other clinical measures such as the circumpapillary retinal nerve fibre layer thickness (cRNFLT). We developed a technique to analyse the RNFL reflectance on the OCT enface images, and to investigate its relation with the cRNFLT. Methods Spectralis ( www.heidelbergengineering.com ) OCT scans of the central retinal ±24° were analysed in the study eye of 31 controls and ...

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    19. OCT image atlas of healthy skin on sun‐exposed areas - O'Leary - - Skin Research and Technology - Wiley Online Library

      OCT image atlas of healthy skin on sun‐exposed areas - O'Leary - - Skin Research and Technology - Wiley Online Library

      Background Skin cancer represents the most prevalent type of cancer in the United States. Excision of these lesions can leave significant scarring, and a delay in the diagnosis of malignant melanoma could result in metastasis or death. Therefore, developing technology and criteria to accurately diagnose these cancers is of particular importance to the medical community. While biopsy can lead to scarring and infections, dermoscopy and confocal microscopy offer noninvasive imaging methods but are also limited in their ability to determine tumor depth and margins. Optical coherence tomography (OCT) is a promising imaging method that uses near‐infrared light backscattering to ...

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    20. Evaluation of two‐dimensional Bruch's membrane opening minimum rim area for glaucoma diagnostics in a large patient cohort

      Evaluation of two‐dimensional Bruch's membrane opening minimum rim area for glaucoma diagnostics in a large patient cohort

      Purpose To characterize the two‐dimensional parameter Bruch's membrane opening minimum rim area (BMO‐MRA) in spectral domain optical coherence tomography (SD‐OCT) of the optic nerve head (ONH) compared to minimum rim width (BMO‐MRW) and retinal nerve fibre layer (RNFL) thickness in a large patient cohort. Methods Case–control, cross‐sectional study of 705 eyes of 445 participants. A total of 449 eyes with glaucoma, 67 eyes with ocular hypertension and 189 healthy controls, underwent SD‐OCT and confocal laser scanning tomography (CSLT), visual field testing and clinical examination. Morphometric ONH parameters, visual field function and diagnostic ...

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    21. Ocular microcirculation measurement with laser speckle flowgraphy and optical coherence tomography angiography in glaucoma

      Ocular microcirculation measurement with laser speckle flowgraphy and optical coherence tomography angiography in glaucoma

      Purpose To compare glaucoma severity with ocular microcirculation, measured with either laser speckle flowgraphy (LSFG) or optical coherence tomography angiography (OCTA). Methods We retrospectively studied 82 eyes of 82 open‐angle glaucoma (OAG) patients who underwent same‐day LSFG and OCTA examinations, with 20 eyes of 20 healthy subjects as controls. In OCTA images, vessel density (VD) (%) was calculated in concentric regions (regions 1, 2 and 3: R1, R2 and R3, respectively) defined by 1.6‐, 3.2‐ and 3.6‐mm‐diameter circles around the optic nerve head (ONH). In R3, the large vessels were automatically masked to calculate ...

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    22. Reflectance confocal microscopy and optical coherence tomography for the diagnosis of bullous pemphigoid and pemphigus and surrounding subclinical lesions

      Reflectance confocal microscopy and optical coherence tomography for the diagnosis of bullous pemphigoid and pemphigus and surrounding subclinical lesions

      Background Diagnosis of bullous pemphigoid (BP) and pemphigus is based on clinical features, histology, immunofluorescence and laboratory data. Objectives To evaluate features of BP and pemphigus at reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) in order to provide a rapid non‐invasive bed‐side diagnosis. Secondary objective was to evaluate the detectability of clinically non‐visible lesions. Methods This was an observational, retrospective, multicentre study in which patients with suspicious lesions for BP or pemphigus underwent clinical assessment, RCM, OCT, blood tests and skin biopsy for histological and direct immunofluorescence examinations from January 2014 to December 2015. A ...

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