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    1. Quantitative depth resolved microcirculation imaging with optical coherence tomography angiography (Part Ι): Blood flow velocity imaging

      Quantitative depth resolved microcirculation imaging with optical coherence tomography angiography (Part Ι): Blood flow velocity imaging

      The research goal of the microvascular network imaging with optical coherence tomography (OCT) angiography is to achieve depth resolved blood flow and vessel imaging in vivo in the clinical management of patents. In this review, we review the main phenomena that have been explored in OCT to image the blood flow velocity vector and the vessels of the microcirculation within living tissues. Parameters that limit the accurate measurements of blood flow velocity are then condisered. Finally, initial Clinic diagnosis applications of and future developments are discussed.

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    2. Quantitative depth resolved microcirculation imaging with optical coherence tomography angiography (Part ΙΙ): Microvascular network imaging

      Quantitative depth resolved microcirculation imaging with optical coherence tomography angiography (Part ΙΙ): Microvascular network imaging

      In this work, we review the main phenomena that have been explored in OCT angiography to image the vessels of the microcirculation within living tissues with the emphasis on how the different processing algorithms were derived to circumvent specific limitations. Parameters are then discussed that can quantitatively describe the depth-resolved microvascular network for possible clinic diagnosis applications. Finally,future directions in continuing OCT development are discussed.

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    3. Speckle variance optical coherence tomography of blood flow in the beating mouse embryonic heart

      Speckle variance optical coherence tomography of blood flow in the beating mouse embryonic heart

      Efficient separation of blood and cardiac wall in the beating embryonic heart is essential and critical for experiment-based computational modelling and analysis of early-stage cardiac biomechanics. Although speckle variance optical coherence tomography (SV-OCT) relying on calculation of intensity variance over consecutively acquired frames is a powerful approach for segmentation of fluid flow from static tissue, application of this method in the beating embryonic heart remains challenging because moving structures generate SV signal indistinguishable from the blood. Here, we demonstrate a modified four-dimensional SV-OCT approach that effectively separates the blood flow from the dynamic heart wall in the beating mouse embryonic ...

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    4. Factors affecting signal strength in spectral-domain optical coherence tomography

      Factors affecting signal strength in spectral-domain optical coherence tomography

      Purpose To identify ocular factors that affect signal strength in spectral-domain optical coherence tomography (SD-OCT). Methods Data from 1312 participants of the population-based Singapore Malay Eye Study-2 (SiMES-2) were included in the analysis. All participants underwent standardized ophthalmic examination, including measurements of best-corrected visual acuity (BCVA), refractive error, axial length, corneal curvature and presence of cataracts. Optic disc and macular cube scans were acquired using the Cirrus HD-OCT (software version 6.0, Carl Zeiss Meditec, Dublin, CA, USA). Signal strength of the optical coherence tomography (OCT) scan was recorded for each study eye. Multivariable linear regression analyses were performed to ...

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    5. Comparison of Bleb Morphology Between Trabeculectomy and Deep Sclerectomy Using a Clinical Grading Scale and Anterior Segment Optical Coherence Tomography.

      Comparison of Bleb Morphology Between Trabeculectomy and Deep Sclerectomy Using a Clinical Grading Scale and Anterior Segment Optical Coherence Tomography.

      Importance This study highlights the role of the filtration bleb for IOP management following Trabeculectomy (TRAB) and deep sclerectomy (DS) in Glaucoma. Background This study serves to analyse the bleb morphology and IOP using the Indiana bleb appearance grading scale (IBAGS) and the anterior-segment optical coherence tomography (AS-OCT) postoperatively and at 3 months. Design Retrospective study by a single surgeon. Participants 28 patients with open-angle glaucoma were recruited into the study, 14 in each of the TRAB (fornix) and DS groups. Methods The surgical intervention was dependent on the irido-corneal angle configuration on gonioscopy. Main Outcome Measures Pre-operatively we collected ...

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    6. Near-IR and CP-OCT imaging of suspected occlusal caries lesions

      Near-IR and CP-OCT imaging of suspected occlusal caries lesions

      Introduction Radiographic methods have poor sensitivity for occlusal lesions and by the time the lesions are radiolucent they have typically progressed deep into the dentin. New more sensitive imaging methods are needed to detect occlusal lesions. In this study, cross-polarization optical coherence tomography (CP-OCT) and near-IR imaging were used to image questionable occlusal lesions (QOC's) that were not visible on radiographs but had been scheduled for restoration on 30 test subjects. Methods Near-IR reflectance and transillumination probes incorporating a high definition InGaAs camera and near-IR broadband light sources were used to acquire images of the lesions before restoration. The ...

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    7. Monitoring retinoschisis and non-acute retinal detachment by optical coherence tomography: morphologic aspects and clinical impact

      Monitoring retinoschisis and non-acute retinal detachment by optical coherence tomography: morphologic aspects and clinical impact

      Purpose To differentiate retinoschisis (RS) from non-acute retinal detachment (naRD) in clinical routine using optical coherence tomography (OCT), describe unique morphological OCT characteristics and monitor disease progression. Methods This prospective, observational study included 64 eyes of 44 patients with either RS or naRD. Patients were examined clinically and using Heidelberg Spectralis OCT ® , Topcon DRI OCT ® and Cirrus HRA-OCT ® over 2 years with follow-up at 1, 3, 6, 12 and 24 months. Main outcomes were typical morphologic findings of RS and naRD described in OCT. Progression was monitored using Spectralis OCT ® follow-up mapping and an eye-tracking method. Results Forty-seven eyes were ...

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    8. Intraoperative optical coherence tomography for soft tissue sarcoma differentiation and margin identification

      Intraoperative optical coherence tomography for soft tissue sarcoma differentiation and margin identification

      Background and Objective Sarcomas are rare but highly aggressive tumors, and local recurrence after surgical excision can occur in up to 50% cases. Therefore, there is a strong clinical need for accurate tissue differentiation and margin assessment to reduce incomplete resection and local recurrence. The purpose of this study was to investigate the use of optical coherence tomography (OCT) and a novel image texture-based processing algorithm to differentiate sarcoma from muscle and adipose tissue. Study Design and Methods In this study, tumor margin delineation in 19 feline and canine veterinary patients was achieved with intraoperative OCT to help validate tumor ...

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    9. Chronic total occlusion is associated with a higher incidence of malapposition and uncovered stent struts: OCT findings at 6 months following DES implantation

      Chronic total occlusion is associated with a higher incidence of malapposition and uncovered stent struts: OCT findings at 6 months following DES implantation

      Objectives To compare stent coverage and malapposition in patients with chronic total occlusion (CTO) lesions and non-CTO lesions (including lipid-rich plaque [LRP] and non-lipid-rich plaque [non-LRP]) after drug-eluting stent (DES) implantation by optical coherence tomography (OCT). Background Different initial lesion characteristics may be related to heterogeneous vessel responses after DES implantation. However, the vessel response in patients with CTO and non-CTO lesions after stenting is unclear. Methods We retrospectively enrolled 64 patients with 68 target lesions. All of the patients underwent OCT imaging immediate after stenting and 6 months after stenting. LRP was defined as the plaque with lipid content ...

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    10. A computer-aided diagnostic system for detecting diabetic retinopathy in optical coherence tomography images

      A computer-aided diagnostic system for detecting diabetic retinopathy in optical coherence tomography images

      Purpose Detection (diagnosis) of diabetic retinopathy (DR) in optical coherence tomography (OCT) images for patients with type 2 diabetes, but almost clinically normal retina appearances. Methods The proposed computer-aided diagnostic (CAD) system detects the DR in three steps: (a) localizing and segmenting 12 distinct retinal layers on the OCT image; (b) deriving features of the segmented layers, and (c) learning most discriminative features and classifying each subject as normal or diabetic. To localise and segment the retinal layers, signals (intensities) of the OCT image are described with a joint Markov-Gibbs random field (MGRF) model of intensities and shape descriptors. Each ...

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    11. Impact of coronary plaque morphology assessed by optical coherence tomography on cardiac troponin elevation in patients with non-ST segment elevation acute coronary syndrome

      Impact of coronary plaque morphology assessed by optical coherence tomography on cardiac troponin elevation in patients with non-ST segment elevation acute coronary syndrome

      Objectives This study aimed to use optical coherence tomography (OCT) to study the relationship between plaque morphology prior to percutaneous coronary intervention (PCI) and post-PCI cardiac troponin (cTn) elevations in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Furthermore, the relationship between these findings and the adverse cardiac events during follow-up was assessed. Background Association between post-PCI cTn elevations and OCT findings in NSTE-ACS patients is unclear. Methods We evaluated 167 patients with stable or falling cTn values after admission who underwent PCI. Periprocedural myocardial injury (PMI) was defined as an cTn increase of more than 70× upper limit of ...

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    12. In-stent neoatherosclerosis and tissue characteristics of restenotic lesions following implantation of second generation drug-eluting stents in unrestricted coronary lesions: Optical frequency domain imaging study

      In-stent neoatherosclerosis and tissue characteristics of restenotic lesions following implantation of second generation drug-eluting stents in unrestricted coronary lesions: Optical frequency domain imaging study

      BACKGROUND Differences in stent platform, polymer coatings, and antirestenotic drugs among the current in use second-generation drug-eluting stents (G2-DESs) may induce significant variations in neointimal response and vascular healing, which may impact the prevalence of neoatherosclerosis (NA) and morphological appearance of the restenotic tissue. METHODS AND RESULTS Utilizing Optical frequency domain imaging, two independent reviewers, retrospectively compared the prevalence of neoatherosclerosis (NA), and the morphological differences, and tissue characteristics of 50 G2-DESs in-stent restenosis (ISR) lesions (35 everolimus-eluting stent [22 cobalt-chromium (CoCr), 13 platinum-chromium (PtCr)], and 15 biolimus-eluting stent [BES]) implanted liberally in unrestricted coronary lesions. More than half of ...

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      Mentions: Kazushige Kadota
    13. Paracentral acute middle maculopathy as a finding in patients with severe vision loss following phacoemulsification cataract surgery

      Paracentral acute middle maculopathy as a finding in patients with severe vision loss following phacoemulsification cataract surgery

      mportance Paracentral acute middle maculopathy (PAMM) as diagnosed by spectral domain optical coherence tomography (SD-OCT) may be associated with "patch off" visual loss post cataract surgery. Background To report a case series of severe vision loss due to PAMM after cataract surgery Design Retrospective case series. Participants Cases from five surgical centres (public and private) in Victoria, Australia. Methods Retrospective analysis of cases with unexplained “patch-off” vision loss post cataract surgery. All patients in our cohort had PAMM and presumed diagnosis of central retinal artery occlusion or transient retinal artery occlusion. Main Outcome Measures A review of the patient's ...

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    14. Optical coherence tomography in biofilm research: A comprehensive review

      Optical coherence tomography in biofilm research: A comprehensive review

      Imaging of biofilm systems is a prerequisite for a better understanding of both structure and its function. The review aims to critically discuss the use of optical coherence tomography (OCT) for the visualization of the biofilm structure as well as its dynamic behavior. A short overview on common and well-known, established imaging techniques for biofilms such as scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), Raman microscopy (RM), and magnetic resonance imaging (MRI) paves the way to imaging biofilms at the mesoscale, which is perfectly covered by means of OCT. Principle, resolution, imaging velocity and limitations of OCT are ...

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    15. In vivo observation of metamorphosis of Plodia interpunctella Hübner using three-dimensional optical coherence tomography

      In vivo observation of metamorphosis of Plodia interpunctella Hübner using three-dimensional optical coherence tomography

      Morphological assessment and three-dimensional reconstructions of internal structures of Plodia interpunctella Hübner during metamorphosis stages were experimentally demonstrated using optical coherence tomography (OCT) for the first time. The conventional, complex sectioning methods were significantly simplified owing to the non-invasive three-dimensional imaging capability of OCT. Further, this study demonstrates the use of OCT as a non-invasive detection tool for in vivo morphological observation of metamorphosis stages to gain a better understanding about the growth of internal organs, which can be considered a useful discovery in the field of entomology. Thus, the metamorphosis stages starting from the larva, three pupa stages ...

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    16. Visualization and tissue classification of human breast cancer images using ultrahigh-resolution OCT

      Visualization and tissue classification of human breast cancer images using ultrahigh-resolution OCT

      Background and Objective Breast cancer is one of the most common cancers, and recognized as the third leading cause of mortality in women. Optical coherence tomography (OCT) enables three dimensional visualization of biological tissue with micrometer level resolution at high speed, and can play an important role in early diagnosis and treatment guidance of breast cancer. In particular, ultra-high resolution (UHR) OCT provides images with better histological correlation. This paper compared UHR OCT performance with standard OCT in breast cancer imaging qualitatively and quantitatively. Automatic tissue classification algorithms were used to automatically detect invasive ductal carcinoma in ex vivo human ...

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    17. From actinic keratosis to squamous cell carcinoma: pathophysiology revisited

      From actinic keratosis to squamous cell carcinoma: pathophysiology revisited

      The precursor of most cutaneous invasive squamous cell carcinomas (iSCCs) is intraepithelial UV-induced damage, known as field cancerization, which can eventually transform into actinic keratosis (AK). Although AK is the most common precursor of iSCC, many AKs will either persist in the same stage or regress, while only a few will progress into iSCC. Nevertheless, because the progression of individual AKs cannot be predicted, it has been proposed that all AKs, regardless of the grade, should be carefully monitored and appropriately treated in clinical practice. Modern imaging techniques such as dermatoscopy, reflectance confocal microscopy (RCM) and high-definition optical coherence tomography ...

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    18. Ex vivo visualization of human ciliated epithelium and quantitative analysis of induced flow dynamics by using optical coherence tomography

      Ex vivo visualization of human ciliated epithelium and quantitative analysis of induced flow dynamics by using optical coherence tomography

      Background and Objective Cilia-driven mucociliary clearance is an important self-defense mechanism of great clinical importance in pulmonary research. Conventional light microscopy possesses the capability to visualize individual cilia and its beating pattern but lacks the throughput to assess the global ciliary activities and flow dynamics. Optical coherence tomography (OCT), which provides depth-resolved cross-sectional images, was recently introduced to this area. Materials and Methods Fourteen de-identified human tracheobronchial tissues are directly imaged by two OCT systems: one system centered at 1,300 nm with 6.5 μm axial resolution and 15 μm lateral resolution, and the other centered at 800 nm ...

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    19. Intraoperative assessment of laryngeal pathologies with optical coherence tomography integrated into a surgical microscope

      Intraoperative assessment of laryngeal pathologies with optical coherence tomography integrated into a surgical microscope

      Objective Endoscopic examination followed by tissue biopsy is the gold standard in the evaluation of lesions of the upper aerodigestive tract. However, it can be difficult to distinguish between healthy mucosa, dysplasia, and invasive carcinoma. Optical coherence tomography (OCT) is a non-invasive technique which acquires high-resolution, cross-sectional images of tissue in vivo . Integrated into a surgical microscope, it allows the intraoperative evaluation of lesions simultaneously with microscopic visualization. Study Design In a prospective case series, we evaluated the use of OCT integrated into a surgical microscope during microlaryngoscopy to help differentiating various laryngeal pathologies. Methods 33 patients with laryngeal pathologies ...

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    20. Early microvascular retinal changes in optical coherence tomography angiography in patients with type 1 diabetes mellitus

      Early microvascular retinal changes in optical coherence tomography angiography in patients with type 1 diabetes mellitus

      Purpose Diabetic retinopathy (DR) can lead to significant vision loss and blindness and has a particularly high prevalence in patients with type 1 diabetes (DM1). In this study, we investigate quantitative differences in optical coherence tomography angiography (OCTA) data between DM1 patients with no or mild signs of retinopathy and non-diabetic subjects. Methods Optical coherence tomography angiography (OCTA) imaging was performed on DM1 patients with no or mild nonproliferative diabetic retinopathy and healthy, age-matched controls. Parafoveal vessel density and foveal avascular zone (FAZ) area in the deep capillary plexus (DCP) and superficial capillary plexus (SCP) were calculated with automated quantification ...

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    21. Non-invasive skin imaging for the diagnosis of myiasis

      Non-invasive skin imaging for the diagnosis of myiasis

      A 52-year-old man presented with a painful ulceration of the scalp (Fig. 1a). He had returned from Guyana the previous week. Dermoscopic examination (FotoFinder Systems GmbH, Bad Birnbach, Germany) showed an intermittent dynamic aspect changing from a sanguineous roundish ulcer (Fig. 1b) to a peculiar roundish structure characterized by a yellowish peripheral ring and a central brownish part (Fig. 1c). High-definition optical coherence tomography (HD-OCT; Skintell ® ; Agfa Gevaert, Antverpen, Belgium) showed a skin cavity (Fig. 2a). Reflectance confocal microscopy (RCM; Vivascope 3000 ® , Caliber, New York, USA, distributed in Europe by MAVIG GmbH, München, Germany) showed the roundish structure observed ...

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      Mentions: AGFA Healthcare
    22. Optical coherence tomography imaging of bullous diseases

      Optical coherence tomography imaging of bullous diseases

      Background  Optical coherence tomography (OCT) is a non-invasive optical imaging technique with a micrometer resolution that may potentially offer real-time bedside imaging of sufficient detail to allow for morphological discrimination between different types of bullae. Objective  To explore the potential of OCT in bullous skin disorders by looking at a set of patients with skin blisters of known origin and study the OCT images for possible hallmarks of the blistering level. Materials and methods  OCT provides cross-sectional, tomographic images of the skin. A consecutive series of patients were recruited and their lesions imaged by OCT: 3 patients with bullous pemphigoid ...

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