1. 1-24 of 243 1 2 3 4 ... 9 10 11 »
    1. Comparison of neointimal coverage and extra-stent lumen between sirolimus and everolimus-eluting stent using optical coherence tomography

      Comparison of neointimal coverage and extra-stent lumen between sirolimus and everolimus-eluting stent using optical coherence tomography

      The external lumen of a stent [defined as extra-stent lumen (ESL)] assessed by optical coherence tomography (OCT) may be related to the risk of thrombus formation after sirolimus-eluting stent (SES) implantation. An everolimus-eluting stent (EES) might provide relatively minimal inflammatory reaction and appropriate neointimal coverage. The purpose of this study was to compare the neointimal thickness and ESL between SES and EES. Patients who underwent OCT examination more than 7 months after either SES or EES implantation were enrolled. Stent area (SA), lumen area (LA), neointimal area (NIA) and neointimal thickness (NIT) of each strut were measured at 1-mm intervals ...

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      Mentions: Takayuki Okamura
    2. The effects of ocular magnification on Spectralis spectral domain optical coherence tomography scan length

      The effects of ocular magnification on Spectralis spectral domain optical coherence tomography scan length

      Purpose The purpose of this study was to assess the effects of incorporating individual ocular biometry measures of corneal curvature, refractive error, and axial length on scan length obtained using Spectralis spectral domain optical coherence tomography (SD-OCT). Methods Two SD-OCT scans were acquired for 50 eyes of 50 healthy participants, first using the Spectralis default keratometry (K) setting followed by incorporating individual mean-K values. Resulting scan lengths were compared to predicted scan lengths produced by image simulation software, based on individual ocular biometry measures including axial length. Results Axial length varied from 21.41 to 29.04 mm. Spectralis SD-OCT ...

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    3. Optical Coherence Tomography. ESASO Course Series Vol. 4

      Optical Coherence Tomography. ESASO Course Series Vol. 4

      The introduction of optical coherence tomography (OCT) into routine clinical practice has massively increased the amount and diversity of information regarding the living retina, and radically changed the understanding and management of almost every retinal disease. Producing an up-to-date book on OCT amid a high technological turnover and rapidly evolving concepts is a challenging task. The authors have succeeded in their mission by selecting certain common and controversial topics rather than attempting to be all-inclusive. This softcover book with 134 pages is a compilation of 15 articles co-authored by 40 contributors forming an international panel of well-respected experts. Each chapter ...

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    4. Wide-field spectral domain-optical coherence tomography in central serous chorioretinopathy

      Wide-field spectral domain-optical coherence tomography in central serous chorioretinopathy

      The aim the study was to describe wide-field spectral-domain optical coherence tomography morphologic relationships of the vitreous, retina, and choroid in central serous chorioretinopathy (CSCR) eyes. Standardized horizontal, vertical, and two oblique (supertemporal to inferonasal and supranasal to inferotemporal) SD-OCT sections were collected for 40 patient with CSCR. For extramacular imaging, images were obtained from eight locations: (1) nasal to the optic disk, (2) extreme nasal periphery, (3) superior to the superotemporal vascular arcade, (4) extreme superior periphery, (5) inferior to the inferotemporal vascular arcade, (6) extreme inferior periphery, (7) temporal to the macula, and (8) extreme temporal periphery. Wide-angle ...

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    5. Advanced Endoscopic Imaging in the Upper Gastrointestinal Tract (Book)

      Advanced Endoscopic Imaging in the Upper Gastrointestinal Tract (Book)

      Advanced endoscopic imaging incorporates several methods to enhance visualization of the upper gastrointestinal tract. It is an evolving field within advanced endoscopy and particularly important for the endoscopist performing ESD, as these modalities can aid all stages of ESD. Advanced imaging involves several different techniques, from chromoendoscopy (e.g. Lugol’s solution, methylene blue, indigo carmine), to optical enhancement methods (e.g. magnified endoscopy, narrow band imaging, confocal endomicroscopy) and electronic methods (e.g. spectrometry, optical coherence tomography). Frequently, a combination of techniques is utilized to maximize visualization of the lesion and surrounding mucosa. The endoscopist performing ESD needs to ...

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    6. Management of intrastromal glass foreign body based on anterior segment optical coherence tomography and Pentacam analysis

      Management of intrastromal glass foreign body based on anterior segment optical coherence tomography and Pentacam analysis

      We read with interest the article by Huda et al. [ 1 ] which reported the clinical aspects and the imaging of a patient with intrastromal glass foreign bodies after a road traffic accident using both anterior segment optical coherence tomography (AS-OCT) and ocular Pentacam, and “demonstrated that AS-OCT and ocular Pentacam are effective and necessary procedures for both the diagnosis and follow-up of intracorneal foreign bodies”. While this paper contributed to our understanding of how AS-OCT and ocular Pentacam may potentially affect the management protocol in these cases, there are relevant additions that we will like to highlight. We encountered a ...

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    7. Motion Artefact Correction in Retinal Optical Coherence Tomography Using Local Symmetry

      Motion Artefact Correction in Retinal Optical Coherence Tomography Using Local Symmetry

      Patient movements during the acquisition of SD-OCT scans create substantial motion artefacts in the volumetric data that hinder registration and 3D analysis and can be mistaken for pathologies. In this paper we propose a method to correct these artefacts using a single volume scan while still retaining the overall shape of the retina. The method was quantitatively validated using a set of synthetic SD-OCT volumes and qualitatively by a group of trained OCT grading experts on 100 SD-OCT scans. Furthermore, we compared the motion compensation estimation by the proposed method with a hardware eye tracker on 100 SD-OCT volumes.

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    8. Comparison of event-based analysis of glaucoma progression assessed subjectively on visual fields and retinal nerve fibre layer attenuation measured by optical coherence tomography

      Comparison of event-based analysis of glaucoma progression assessed subjectively on visual fields and retinal nerve fibre layer attenuation measured by optical coherence tomography

      The purpose is to study the ability of an event-based analysis of retinal nerve fibre layer (RNFL) attenuation measured by Stratus ® optical coherence tomography (OCT) and to detect progression across the spectrum of glaucoma. Adult glaucoma suspects, ocular hypertensives and glaucoma patients who had undergone baseline RNFL thickness measurement on Stratus OCT and reliable automated visual field examination by Humphrey’s visual field analyser prior to March 2007 and had 5-year follow-up data were recruited. Progression on OCT was defined by two criteria: decrease in average RNFL thickness from baseline by at least 10 and 20 µ. Visual field progression was ...

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    9. Three-dimensional optic nerve head images using optical coherence tomography with a broad bandwidth, femtosecond, and mode-locked laser

      Three-dimensional optic nerve head images using optical coherence tomography with a broad bandwidth, femtosecond, and mode-locked laser

      Purpose The aim of this study was to demonstrate the fine laminar structure of the optic nerve head (ONH), in vivo, using a broad wavelength, ultra-high resolution, and optically coherent tomography (OCT) system. Methods This high-resolution OCT system, based on a 200 nm bandwidth spectrometer and an 8 femtosecond ultra-short, mode-locked, coherent laser light source, enabled in vivo cross-sectional ONH imaging with 2.0 μm axial resolution. A total of 300 optic disc B-scans, which consisted of 300 × 2048 pixels, were obtained in 10 μm steps. Three-dimensional images were rendered from these images to obtain n face images of the ...

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    10. Effect of optical clearing agents on optical coherence tomography images of cervical epithelium

      Effect of optical clearing agents on optical coherence tomography images of cervical epithelium

      Optical coherence tomography (OCT) can be used as an adjunct to colposcopy in order to detect precancerous and cancerous cervical lesions. Optical clearing agents (OCAs) temporarily reduce the optical scattering of biological tissues. The purpose of this study was to investigate their influence on OCT imaging. OCT images were taken from unsuspicious and suspicious areas of fresh conization specimens immediately after resection and 5, 10, and 20 min after application of dimethyl sulfoxide ( DMSO ) or polyethylene glycol (PEG). Corresponding histologies were obtained from all sites. The images taken 5, 10, and 20 min after application of OCA were compared to ...

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    11. Evaluation of filtering blebs exhibiting transconjunctival oozing using anterior segment optical coherence tomography

      Evaluation of filtering blebs exhibiting transconjunctival oozing using anterior segment optical coherence tomography

      Purpose To explore the features of filtering blebs exhibiting transconjunctival oozing via three-dimensional anterior segment optical coherence tomography (3D AS-OCT). Methods In this cross-sectional study, 131 eyes of 131 patients exhibiting filtering blebs were examined. Of those, 20 eyes were excluded as flat-shaped, non-functioning bleb. Transconjunctival oozing was defined as transconjunctival aqueous egress evident on the bleb surface, in the absence of any point leak observable using a slit-lamp, as confirmed by application of digital pressure. Total bleb height, the height of the fluid-filled cavity, and bleb wall thickness and density were measured using 3D AS-OCT. Patient age, the etiology ...

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    12. Optical coherence tomography and electrophysiological findings in torpedo maculopathy

      Optical coherence tomography and electrophysiological findings in torpedo maculopathy

      Purpose To describe the morphofunctional findings in a 6-year-old child with a unilateral lesion of the temporal macula called “torpedo maculopathy” throughout a 1-year follow-up. Methods Evaluation of retinal morphology and function was assessed by means of spectral-domain OCT scans, best-corrected visual acuity, full-field flash electroretinogram (ERG), multifocal electroretinogram (mfERG) and pattern visual evoked potentials (VEP). Patient was examined every 4 months for a 1-year follow-up time. Results Torpedo maculopathy consisted in a sharply demarcated hypopigmented oval iuxta-macular lesion (1.5 DD wide × 0.7 DD high). The baseline visual acuity of the affected eye was 20/25. OCT showed ...

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    13. Noninvasive Ocular Angiography by Optical Coherence Tomography (Book Chapter)

      Noninvasive Ocular Angiography by Optical Coherence Tomography (Book Chapter)

      Diabetic retinopathy, age-related macular degeneration, and glaucoma are all associated with impaired circulation. Noninvasive assessment of ocular circulation would be very powerful for understanding and diagnosing these eye diseases. Using high-speed optical coherence tomography (OCT), we developed a new OCT angiography algorithm called split-spectrum amplitude-decorrelation angiography (SSADA) for imaging ocular microcirculation. Here, the system and theory of this novel OCT angiography technique are reviewed; its capabilities for imaging retinal, choroidal, and optic nerve head blood flow are demonstrated; and its limitation is discussed.

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    14. Imaging of cardiovascular development in Mammalian embryos using optical coherence tomography (Book Chapter)

      Imaging of cardiovascular development in Mammalian embryos using optical coherence tomography (Book Chapter)

      The cardiovascular system is the first functional organ system to develop within the mammalian embryo. During the early stages of cardiovascular development, the heart and blood vessels undergo rapid growth and remodeling required for embryo viability, proper morphogenesis, and the function of all organ systems. Live imaging of these dynamic events in early mouse embryos is critical to understanding when and how these morphological changes occur during normal development and how mutations and pharmacological agents affect cardiovascular structure and function in vivo. The use of optical coherence tomography (OCT) allows for rapid, three-dimensional structural and functional imaging of mouse embryos ...

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    15. Identification and biometry of horizontal extraocular muscle tendons using optical coherence tomography

      Identification and biometry of horizontal extraocular muscle tendons using optical coherence tomography

      Purpose To purpose if this study was to determine whether the horizontal rectus muscle tendons (HRMTs) can be observed using anterior segment optical coherence tomography (AS-OCT) and to determine the repeatability of its measurements. Also, this study aimed to observe and measure the different external ocular structures at the level of the horizontal rectus muscle (HRM) insertion. Methods This was a retrospective, observational, descriptive and comparative study. Images were obtained utilizing the RTVue 100 CAM system. Eyes were analyzed at the three and nine o’clock position. Scans were performed for three different locations: the limbus, the ciliary body and ...

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    16. Optical Coherence Tomography to Assess Neurodegeneration in Multiple Sclerosis (Book Chapter)

      Optical Coherence Tomography to Assess Neurodegeneration in Multiple Sclerosis (Book Chapter)

      Retinal spectral domain optical coherence tomography (OCT) has emerged as a clinical and research tool in multiple sclerosis (MS) and optic neuritis (ON). This chapter summarizes a short OCT protocol as included in international consensus guidelines. The protocol was written for hands-on style such that both clinicians and OCT technicians can make use of it. The protocol is suitable for imaging of the optic nerve head and macular regions as a baseline for follow-up investigations, individual layer segmentation, and diagnostic assessment.

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    17. Intraoperative optical coherence tomography imaging to identify parathyroid glands

      Intraoperative optical coherence tomography imaging to identify parathyroid glands

      Objective Optical coherence tomography (OCT) is a non-invasive high-resolution imaging technique that permits characterization of microarchitectural features in real time. Previous ex vivo studies have shown that the technique is capable of distinguishing between parathyroid tissue, thyroid tissue, lymph nodes, and adipose tissue. The purpose of this study was to evaluate the practicality of OCT during open and minimally invasive parathyroid and thyroid surgery. Methods During parathyroid and thyroid surgery, OCT images were generated from parathyroid glands, thyroid tissue, lymph nodes, and adipose tissue. The images were immediately assessed by the operating team using the previously defined criteria. Second, the ...

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    18. Optical Coherence Tomography for Quantitative Diagnosis in Cardiovascular Disease (Book Chapter)

      Optical Coherence Tomography for Quantitative Diagnosis in Cardiovascular Disease (Book Chapter)

      In recent years, biomedical imaging technology has made rapid advances that enable the visualization, quantification, and monitoring of morphology and function. There are several tomography modalities which are currently used in clinics, such as computed tomography (CT), positron emission tomography (PET), magnetic resonance imaging (MRI), ultrasound (US), etc. These modalities have been developed for in vivo structural and functional imaging in humans, but frequently require large, expensive and complex systems. The penetration depth of these tomographic techniques is long, but the spatial resolution is typically on the order of several millimeters or hundred of micrometers.

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    19. Development of Tissue Characterization Using Optical Coherence Tomography for Defining Coronary Plaque Morphology and the Vascular Responses After Coronary Stent Implantation

      Development of Tissue Characterization Using Optical Coherence Tomography for Defining Coronary Plaque Morphology and the Vascular Responses After Coronary Stent Implantation

      Cardiovascular disease is associated with a high burden of mortality secondary to acute coronary events. Assessment for vulnerable plaque and an understanding of the etiology of stent failure by intravascular imaging may facilitate a greater understanding of the underlying processes responsible for adverse clinical outcomes and guide future therapy. This review focuses on the role of optical coherence tomography in tissue characterization and highlights future advances within the field providing potential enhancement of image interpretation.

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    20. Microscale imaging of cilia-driven fluid flow

      Microscale imaging of cilia-driven fluid flow

      Cilia-driven fluid flow is important for multiple processes in the body, including respiratory mucus clearance, gamete transport in the oviduct, right–left patterning in the embryonic node, and cerebrospinal fluid circulation. Multiple imaging techniques have been applied toward quantifying ciliary flow. Here, we review common velocimetry methods of quantifying fluid flow. We then discuss four important optical modalities, including light microscopy, epifluorescence, confocal microscopy, and optical coherence tomography, that have been used to investigate cilia-driven flow.

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    21. Optical Coherence Tomography for Prostate Cancer and Beyond (Book Chapter)

      Optical Coherence Tomography for Prostate Cancer and Beyond (Book Chapter)

      Since it was first used to evaluate human genitourinary tissue in 1997, OCT has emerged as a promising modality to provide real-time, high-resolution imaging of urologic organs. In the bladder, it has demonstrated a high sensitivity in identifying regions of the bladder suspicious for CIS and between invasive and noninvasive malignancy; it has been studied as an “optical biopsy” both during the initial cystoscopic diagnosis and intraoperatively in bladder-preserving surgery. Several small, ex vivo studies have shown promising results in the ability of OCT to demonstrate histopathologic alterations to renal morphology such as in renal ischemia and malignancy. It may ...

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    22. Optical Coherence Tomography in Bladder Cancer (Book Chapter)

      Optical Coherence Tomography in Bladder Cancer (Book Chapter)

      The current diagnostic standard for grading and staging of non-muscle-invasive bladder cancer (NMIBC) is based on the histopathology obtained during transurethral resection of the bladder tumour (TURBT) or biopsies. Although considered reference standard, this technique has some limitations: First, no real-time intraoperative histological information is obtained on stage and grade. Real-time intraoperative histological information could be helpful when NMIBC is treated by electric coagulation or laser ablation. The urologist has to rely on his/her judgement of stage and grade since no tissue is harvested for histological confirmation. In addition, in many centres, patients with a history of low-grade, non-invasive ...

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    23. Evaluation of IVOCT imaging of coronary artery metallic stents with neointimal coverage

      Evaluation of IVOCT imaging of coronary artery metallic stents with neointimal coverage

      Accuracy of IVOCT for measurement of neointimal thickness and effect of neointima in the appearance of metallic struts in IVOCT images was investigated. Phantom vessels were constructed and coronary stents were deployed and covered with thick (250–400 μm) and thin (30–70 μm) phantom neointima. High resolution Micro-CT images of the stent struts were recorded as a gold standard. IVOCT images of the phantom vessels were acquired with various luminal blood scattering strengths and measured neointimal thicknesses from IVOCT and Micro-CT images were compared. In transparent lumen, comparison of IVOCT and Micro-CT neointima thickness measurements found no significant difference ...

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    24. In vitro assessment of effects of hyperglycemia on the optical properties of blood during coagulation using optical coherence tomography

      In vitro assessment of effects of hyperglycemia on the optical properties of blood during coagulation using optical coherence tomography

      No published reports have demonstrated the capability of the optical coherence tomography technique for quantifying the optical coherence tomography signal slope, 1/e light penetration depth, and attenuation coefficient of hyperglycemic blood by an in vitro assessment. The purpose of this study was to investigate the effects of hyperglycemia on optical properties during in vitro blood coagulation by optical coherence tomography. Normal whole blood acted as the control group. After 1-h coagulation, the average optical coherence tomography signal slope decreased approximately 23.3 and 16.7 %, and the 1/e light penetration depths increased approximately 21.5 and 19.2 ...

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    1-24 of 243 1 2 3 4 ... 9 10 11 »
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