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    1. Optical coherence tomography guided carotid artery stent procedure: technique and potential applications

      Optical coherence tomography guided carotid artery stent procedure: technique and potential applications

      Objectives To (1) present a guide on how to perform optical coherence tomography (OCT) in carotid artery stenting (CAS), to (2) highlight several instructive cases illustrating OCT-guidance as an interventional strategy, and to (3) present the largest case-series of OCT-guided CAS performed in North America, demonstrating its feasibility as an imaging modality in this setting. Background OCT is an intravascular imaging method that captures images with an axial resolution 10 times higher than intravascular ultrasound. OCT has proven to be a useful modality in coronary angiography and may have similar applications in evaluating carotid atherosclerotic disease. Methods We compared our ...

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    2. Canine central corneal thickness measurements via Pentacam-HR®, optical coherence tomography (Optovue iVue®), and high-resolution ultrasound biomicroscopy

      Canine central corneal thickness measurements via Pentacam-HR®, optical coherence tomography (Optovue iVue®), and high-resolution ultrasound biomicroscopy

      Objective To compare central corneal thickness (CCT) values in canine eyes using Pentacam-HR ® Scheimpflug imaging (Pentacam), Optovue ® iVue spectral-domain optical coherence tomography (SD-OCT), and high-resolution ultrasound biomicroscopy (UBM) and generate normative canine Pentacam CCT values. Animals studied Twenty-four client-owned dogs (37 eyes) with nondiseased cornea(s) presenting to the Colorado State University Veterinary Teaching Hospital. Procedures Corneal images were acquired via Pentacam, SD-OCT, and UBM in the listed order. Machine-calculated values of CCT from Pentacam and SD-OCT were compared to operator-measured values from UBM. Bland–Altman analysis was performed to evaluate agreement between instruments. Results Mean CCT ± SD measured by ...

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      Mentions: Optovue
    3. An optical coherence tomography study of neointimal morphology and strut coverage at different time intervals from implantation of biodegradable polymer-coated sirolimus-eluting stents

      An optical coherence tomography study of neointimal morphology and strut coverage at different time intervals from implantation of biodegradable polymer-coated sirolimus-eluting stents

      Objectives The aim of the study was to capture the evolution of neointima after implantation of a biodegradable polymer–coated, sirolimus–eluting, cobalt–chromium coronary stent system (BP-DES). Background Optical coherence tomography (OCT) suggests that in-stent neointimal morphology influences clinical outcomes after DES implantation. Methods Sixty patients treated with single BP-DES implantation were examined by quantitative coronary angiography (QCA) and OCT at 3, 6, and 12-month follow-up. Results Median late lumen loss by QCA (mm) was 0.04 (IQR 0, 0.08), 0.17 (IQR 0, 0.32), and 0.14 (IQR 0.07, 0.31) at 3, 6, and ...

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    4. Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography

      Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography

      The human eyes provide a natural window for noninvasive measurement of the pulse wave velocity (PWV) of small arteries. By measuring the retinal PWV, the stiffness of small arteries can be assessed, which may better detect early vascular diseases. Therefore, retinal PWV measurement has attracted increasing attention. In this study, a jump-scanning method was proposed for non-invasive measurement of retinal PWV using spectral-domain OCT. The jump-scanning method uses the phase-resolved Doppler OCT to obtain the pulse shapes. To realize PWV measurement, the jump-scanning method extracts the transit time of the pulse wave from an original OCT scanning site to another ...

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    5. Microvasculature dropout detected by the optical coherence tomography angiography in nonarteritic anterior ischemic optic neuropathy

      Microvasculature dropout detected by the optical coherence tomography angiography in nonarteritic anterior ischemic optic neuropathy

      Objective To investigate microcirculation characteristics of peripapillary superficial retina and optic disc in eyes with nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA). Methods Forty-one eyes of 30 NAION patients and 30 eyes of 30 normal subjects were evaluated with OCTA (AngioVue, Optovue). The whole vessel density, inside disc vessel density, peripapillary vessel density, and vessel densities based on the sectorial division in the nerve head mode peripapillary superficial retina and RPC mode optic disc were measured respectively. Results In the NAION group, vessel densities in both the peripapillary superficial retina and optic disc were significant ...

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    6. Characterizing biochemical and morphological variations of clinically relevant anatomical locations of oral tissue in vivo with hybrid Raman spectroscopy and optical coherence tomography technique

      Characterizing biochemical and morphological variations of clinically relevant anatomical locations of oral tissue in vivo with hybrid Raman spectroscopy and optical coherence tomography technique

      his study aims to characterize biochemical and morphological variations of the clinically relevant anatomical locations of in vivo oral tissue (i.e., alveolar process, lateral tongue, and floor of the mouth) by using hybrid Raman spectroscopy (RS) and optical coherence tomography (OCT) technique. A total of 1049 in vivo fingerprint (FP: 800-1800 cm -1 ) and high wavenumber (HW: 2800-3600 cm -1 ) Raman spectra were acquired from different oral tissue (alveolar process=331; lateral tongue=339, and floor of mouth=379) of 26 normal subjects in the oral cavity under the OCT imaging guidance. The total Raman dataset were split into ...

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    7. Investigating the healing mechanisms of an angiogenesis-promoting topical treatment for diabetic wounds using multimodal microscopy

      Investigating the healing mechanisms of an angiogenesis-promoting topical treatment for diabetic wounds using multimodal microscopy

      Impaired skin wound healing is a significant co-morbid condition of diabetes that is caused by poor microcirculation, among other factors. Studies have shown that angiogenesis, a critical step in the wound healing process in diabetic wounds, can be promoted under hypoxia. In this study, an angiogenesis-promoting topical treatment for diabetic wounds, which promotes angiogenesis by mimicking a hypoxic environment via inhibition of prolyl hydroxylase resulting in elevation or maintenance of hypoxia inducible factor (HIF), was investigated utilizing a custom-built multimodal microscopy system equipped with phase-variance optical coherence tomography (PV-OCT) and fluorescence lifetime imaging microscopy (FLIM). PV-OCT was used to track ...

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    8. Flexible wide-field optical micro-angiography based on Fourier-domain multiplexed dual-beam swept source optical coherence tomography

      Flexible wide-field optical micro-angiography based on Fourier-domain multiplexed dual-beam swept source optical coherence tomography

      Wide-field optical coherence tomography angiography (OCTA) is gaining interest in clinical imaging applications. In this pursuit, it is challenging to maintain the imaging resolution and sensitivity throughout the wide field of view (FoV). Here, we propose a novel method/system of dual-beam arrangement and Fourier domain multiplexing to achieve wide field OCTA when imaging the uneven surface samples. The proposed system provides two separate FoVs, with flexibility that the imaging area, focus of the imaging beam and imaging depth range can be individually adjusted for each FoV, leading to either 1) increased system imaging FoV or 2) capability of targeting ...

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    9. Real-time optical coherence tomography coregistration with angiography in percutaneous coronary intervention–impact on physician decision-making: The OPTICO-integration study

      Real-time optical coherence tomography coregistration with angiography in percutaneous coronary intervention–impact on physician decision-making: The OPTICO-integration study

      Aims Intracoronary optical coherence tomography (OCT) imaging allows for high-resolution characterization of coronary lesions. Difficulties in matching cross-sectional OCT-images with angiographic lesion localization may limit optimal clinical utilization. We sought to prospectively assess the impact of a novel system of real-time OCT coregistration with angiography (ACR) on physician decision-making during percutaneous coronary interventions (PCI). Methods and Results Strategy for PCI (stent - length, - diameter, - strategy, landing zone) and PCI-optimization (stent-malappostion, -underexpansion, edge-dissections, geographical mismatch) was prospectively assessed in 50 patients with 58 coronary lesions after (I) angiography, (II) OCT imaging, and (III) ACR. Preprocedural OCT imaging altered stent-length (58.9%), diameter ...

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    10. Evaluation of retinal nerve fibre layer, ganglion cell layer and choroidal thickness with optical coherence tomography in migraine patients: a case-control study

      Evaluation of retinal nerve fibre layer, ganglion cell layer and choroidal thickness with optical coherence tomography in migraine patients: a case-control study

      Background Evaluation of retinal nerve fibre layer (RNFL), ganglion cell layer (GCL) and choroidal thickness (CT) with optical coherence tomography (OCT) in chronic migraine patients, to compare with healthy controls. Material and Method Ninety-four eyes of 47 chronic migraine patients (Group 1) and 68 eyes of 34 healthy individuals (Group 2) were included in this prospective case-control study. The right and left eyes were separately evaluated. Mean peripapillary RNFL thicknesses, mean GCL measured from superior and inferior quadrants, and mean CT were measured at three different regions (central, 500 μm nasal and temporal region of the fovea). Results There was ...

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    11. Clinical relevance of retinal structure in children with laser-treated retinopathy of prematurity versus controls – using optical coherence tomography

      Clinical relevance of retinal structure in children with laser-treated retinopathy of prematurity versus controls – using optical coherence tomography

      Purpose We aimed to assess the macular anatomy using spectral domain optical coherence tomography (SD-OCT), in children born preterm who had laser-treated retinopathy of prematurity (ROP), and to investigate the relationship between structural changes in macula and visual function. Methods Thirty-seven 3–8 years old children were included in the study in two groups: 20 children born preterm [(<34 weeks of gestation, birthweight (BW) <2000 g)] who had laser-treated ROP in the Neonatology Department, Municipal Clinical Emergency Hospital of Timisoara, Romania; and 17 controls (children born at term, without eye disease, matched for age and gender). Spectral domain optical coherence ...

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    12. Structural and functional imaging of aqueous humor outflow: a review

      Structural and functional imaging of aqueous humor outflow: a review

      Maintaining healthy aqueous humor outflow (AHO) is important for intraocular cellular health and stable vision. Impairment of AHO can lead to increased intraocular pressure, optic nerve damage, and concomitant glaucoma. An improved understanding of AHO will lead to improved glaucoma surgeries that enhance native AHO as well as facilitate the development of AHO-targeted pharmaceuticals. Recent AHO imaging has evolved to live human assessment and has focused on the structural evaluation of AHO pathways and the functional documentation of fluid flow. Structural AHO evaluation is predominantly driven by optical coherence tomography, and functional evaluation of flow is performed using various methods ...

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    13. Using Vascular Landmarks to Orient 3D Optical Coherence Tomography Images of the Mouse Eye

      Using Vascular Landmarks to Orient 3D Optical Coherence Tomography Images of the Mouse Eye

      Comparing 3D structural information obtained by optical coherence tomography (OCT) requires accurate alignment of images acquired from individual subjects. Despite the widespread use of OCT to image the anterior and posterior mouse eye, few approaches to align the resulting image data have been described, in part due to a lack of well-characterized landmarks that are suitable for alignment. Here, we provide an OCT acquisition and analysis protocol that incorporates the use of the long posterior ciliary arteries as landmarks. In mammals, these two large choroidal vessels lie in a plane approximately parallel to the horizon. Our OCT imaging approach resolves ...

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    14. Diagnostic accuracy of optical coherence tomography Inter-Eye Percentage Difference (IEPD) for optic neuritis in multiple sclerosis - Coric - 2017 - European Journal of Neurology - Wiley Online Library

      Diagnostic accuracy of optical coherence tomography Inter-Eye Percentage Difference (IEPD) for optic neuritis in multiple sclerosis - Coric - 2017 - European Journal of Neurology - Wiley Online Library

      Background Multiple sclerosis (MS) associated optic neuritis (MSON) causes atrophy of the inner retinal layers, which can be quantified by optical coherence tomography (OCT). It has been suggested that the Inter-Eye Percentage Difference (IEPD) of atrophy may be of diagnostic value in MSON. Methods Prospective, cross-sectional study in MS patients and healthy controls (HC). Spectral-domain OCT of both eyes was performed, followed by automated retinal layer segmentation of the peripapillary retinal nerve fibre layer (pRNFL) and macular ganglion cell and inner plexiform layer (mGCIPL). Receiver Operator Characteristics Curves were plotted and the area under the curve (AUC) was calculated for ...

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    15. Optical coherence tomography for the investigation of frontal fibrosing alopecia

      Optical coherence tomography for the investigation of frontal fibrosing alopecia

      Background FFA is a cicatricial alopecia that affects the frontotemporal hairline, eyebrows, and body hair. OCT is a non-invasive imaging technique useful in understanding skin architecture and vascularization. Objective To describe structural and vascular findings in FFA using OCT. Methods This was a case-control study conducted from the months of December 2016-February 2017. The study was IRB approved and conducted at the University of Miami Hospital outpatient dermatology hair and nail clinic in Miami, FL. Four patients with biopsy proven FFA, and three healthy age and sex-matched controls participated. OCT scans were taken on cicatricial alopecic band, inflammatory hairline, eyebrow ...

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    16. In vivo multiphoton microscopy using a handheld scanner with lateral and axial motion compensation

      In vivo multiphoton microscopy using a handheld scanner with lateral and axial motion compensation

      This paper reports a handheld multiphoton fluorescence microscope designed for clinical imaging that incorporates axial motion compensation and lateral image stabilization. Spectral domain optical coherence tomography is employed to track the axial position of the skin surface, and lateral motion compensation is realised by imaging the speckle pattern arising from the optical coherence tomography beam illuminating the sample. Our system is able to correct lateral sample velocities of up to ~65 μm s -1 . Combined with the use of negative curvature microstructured optical fibre to deliver tunable ultrafast radiation to the handheld multiphoton scanner without the need of a dispersion ...

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    17. Central retinal preservation in rdAc cats

      Central retinal preservation in rdAc cats

      Objective Children with Leber congenital amaurosis (LCA) due to CEP290 mutations show characteristic macular preservation. Spectral domain-optical coherence tomography (SD-OCT) is a noninvasive technique to investigate retinal structural changes. Loss of integrity of the ellipsoid zone (EZ) on OCT in people with retinal disease has been associated with loss of visual function and is a useful measure of retinal disease progression. We hypothesized that rdAc felines with Cep290 mutation would have a similar pattern of degeneration, with relative central retinal preservation associated with maintenance of the EZ. Procedures Fundus imaging, confocal scanning laser ophthalmoscopy, and SD-OCT cross-sectional imaging was performed ...

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    18. Pixel classification method in optical coherence tomography for tumor segmentation and its complementary usage with OCT microangiography

      Pixel classification method in optical coherence tomography for tumor segmentation and its complementary usage with OCT microangiography

      A novel machine-learning method to distinguish between tumor and normal tissue in optical coherence tomography (OCT) has been developed. Pre-clinical murine ear model implanted with mouse colon carcinoma CT-26 was used. Structural-image-based feature sets were defined for each pixel and machine learning classifiers were trained using “ground truth” OCT images manually segmented by comparison with histology. The accuracy of the OCT tumour segmentation method was then quantified by comparing with fluorescence imaging of tumors expressing genetically encoded fluorescent protein KillerRed that clearly delineates tumor borders. Since the resultant 3D tumor/normal structural maps are inherently co-registered with OCT derived maps ...

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    19. Hemodynamic analysis of a novel bioresorbable scaffold in porcine coronary artery model

      Hemodynamic analysis of a novel bioresorbable scaffold in porcine coronary artery model

      Background The shear stress distribution assessment can provide useful insights for the hemodynamic performance of the implanted stent/scaffold. Our aim was to investigate the effect of a novel bioresorbable scaffold, Mirage on local hemodynamics in animal models. Method The main epicardial coronary arteries of 7 healthy mini-pigs were implanted with 11 Mirage Microfiber sirolimus-eluting Bioresorbable Scaffolds (MMSES). Optical coherence tomography (OCT) was performed post scaffold implantation and the obtained images were fused with angiographic data to reconstruct the coronary artery anatomy. Blood flow simulation was performed and Endothelial Shear Stress(ESS) distribution was estimated for each of the 11 ...

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    20. Endomicroscopic optical coherence tomography for cellular resolution imaging of gastrointestinal tracts

      Endomicroscopic optical coherence tomography for cellular resolution imaging of gastrointestinal tracts

      Our ability to detect neoplastic changes in gastrointestinal (GI) tracts is limited by the lack of an endomicroscopic imaging tool that provides cellular-level structural details of GI mucosa over a large tissue area. In this paper, we report a fiber-optic based micro-optical coherence tomography (μOCT) system and demonstrate its capability to acquire cellular-level details of GI tissue through circumferential scanning. The system achieves an axial resolution of 2.48 µm in air and a transverse resolution of 4.8 µm with a depth-of-focus (DOF) of ~150 µm. To mitigate the issue of limited DOF, we used a rigid sheath to ...

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    21. Optical coherence tomography image-guided smart laser knife for surgery

      Optical coherence tomography image-guided smart laser knife for surgery

      Background and Objective Surgical oncology can benefit from specialized tools that enhance imaging and enable precise cutting and removal of tissue without damage to adjacent structures. The combination of high-resolution, fast optical coherence tomography (OCT) co-aligned with a nanosecond pulsed thulium (Tm) laser offers advantages over conventional surgical laser systems. Tm lasers provide superior beam quality, high volumetric tissue removal rates with minimal residual thermal footprint in tissue, enabling a reduction in unwanted damage to delicate adjacent sub-surface structures such as nerves or micro-vessels. We investigated such a combined Tm/OCT system with co-aligned imaging and cutting beams—a configuration ...

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