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    1. Optical coherence tomography angiography in age-related macular degeneration: persistence of vascular network in quiescent choroidal neovascularization

      Optical coherence tomography angiography in age-related macular degeneration: persistence of vascular network in quiescent choroidal neovascularization

      This study was supported by the Werner H. Spross Foundation (Zurich, Switzerland). The ‘Stiftung wissenschaftliche Forschung, Fonds Ophthalmologie, City Hospital Triemli’ received research grants from Novartis Schweiz AG and Bayer Schweiz AG and payments for invited talks or advisory board participations for M.B and S.M. from Allergan, Novartis, Alimera, Bayer, Roche and Clanotech. None of the authors above has any conflict of interest related to this research. This study was presented as an e-poster (POS- 6771) at the 15th EURETINA Congress in Nice, France (17. – 20.09.2015).

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      Mentions: Stephan Michels
    2. Laser thermal therapy monitoring using complex differential variance in optical coherence tomography

      Laser thermal therapy monitoring using complex differential variance in optical coherence tomography

      Conventional thermal therapy monitoring techniques based on temperature are often invasive, limited by point sampling, and are indirect measures of tissue injury, while techniques such as magnetic resonance and ultrasound thermometry are limited by their spatial resolution. The visualization of the thermal coagulation zone at high spatial resolution is particularly critical to the precise delivery of thermal energy to epithelial lesions. In this work, an integrated thulium laser thermal therapy monitoring system was developed based on complex differential variance (CDV), which enables the 2D visualization of the dynamics of the thermal coagulation process at high spatial and temporal resolution with ...

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    3. Semi-automated ICRS scoring of equine articular cartilage lesions in optical coherence tomography images

      Semi-automated ICRS scoring of equine articular cartilage lesions in optical coherence tomography images

      Background Arthroscopic optical coherence tomography (OCT) is a promising tool for detailed evaluation of articular cartilage injuries. However, OCT-based articular cartilage scoring still relies on the operator's visual estimation. Objectives To test the hypothesis that semi-automated ICRS (International Cartilage Repair Society) scoring of chondral lesions seen in OCT images could enhance intra- and inter-observer agreement of the scoring and its accuracy. Study design Validation study, using equine cadaver tissue. Methods Osteochondral samples ( n = 99) were prepared from eighteen equine metacarpophalangeal joints and imaged using OCT. Custom-made software was developed for semi-automated ICRS scoring of cartilage lesions on OCT images ...

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    4. The association between retinal nerve fibre layer thickness and N-acetyl aspartate levels in multiple sclerosis brain normal-appearing white matter: a longitudinal study using magnetic resonance spectroscopy and optical coherence tomography

      The association between retinal nerve fibre layer thickness and N-acetyl aspartate levels in multiple sclerosis brain normal-appearing white matter: a longitudinal study using magnetic resonance spectroscopy and optical coherence tomography

      Background and purpose N -acetyl aspartate (NAA) assessed using proton magnetic resonance spectroscopy ( 1 H MRS) has a high pathological specificity for axonal density. Retinal nerve fibre layer thickness (RNFLT) measured by using optical coherence tomography is increasingly used as a surrogate marker of neurodegeneration in multiple sclerosis (MS). Our aim was to investigate the relation between RNFLT and NAA/creatine in brain normal-appearing white matter (NAWM), their dynamics over time and the association with clinical outcome measures in relapsing MS. T2 WM lesions served as control tissue. Methods Forty-three MS patients underwent standardized neurological examination including the Expanded Disability ...

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    5. Simplifying the assessment of human breast cancer by mapping a micro-scale heterogeneity index in optical coherence elastography

      Simplifying the assessment of human breast cancer by mapping a micro-scale heterogeneity index in optical coherence elastography

      Surgical treatment of breast cancer aims to identify and remove all malignant tissue. Intraoperative assessment of tumor margins is, however, not exact; thus, re-excision is frequently needed, or excess normal tissue is removed. Imaging methods applicable intraoperatively could help to reduce re-excision rates whilst minimizing removal of excess healthy tissue. Optical coherence elastography (OCE) has been proposed for use in breast-conserving surgery; however, intraoperative interpretation of complex OCE images may prove challenging. Observations of breast cancer on multiple length scales, by OCE, ultrasound elastography, and atomic force microscopy, have shown an increase in the mechanical heterogeneity of malignant breast tumors ...

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    6. Tail artifact removal in OCT angiography images of rodent cortex

      Tail artifact removal in OCT angiography images of rodent cortex

      Optical coherence tomography angiography (OCTA) is a surging non-invasive, label-free, in vivo volumetric imaging method, currently being translated to clinical ophthalmology and becoming popular in neuroscience. Despite its attractiveness, there is an inherent issue of using OCT angiograms for quantitative cerebrovascular studies: The dynamic scattering of moving erythrocytes within pial vasculature creates tail-like artifacts that shadow the capillary vessels in the deeper layers of cortex. This false flow effect is relatively benign for qualitative visualization purposes, but it might have a significant impact on quantitative interpretation of angiographic results. In this work, we propose a simple image processing method to ...

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    7. Pachychoroid neovasculopathy: aspect on optical coherence tomography angiography

      Pachychoroid neovasculopathy: aspect on optical coherence tomography angiography

      Purpose To describe and interpret the features of pachychoroid neovasculopathy (PNV) using optical coherence tomography angiography (OCTA) technique. Methods This is an observational case series of patients who presented with PNV. Best-corrected visual acuity (BCVA), anterior segment examination, dilated funduscopic examination, infrared and autofluorescence fundus images and spectral-domain optical coherence tomography (SD-OCT; B-scan, ‘en-face’ and OCTA) were carried out for all patients. Choroid thickness was measured using enhanced depth imaging (EDI) mode. Colour fundus photographs, fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were not performed systematically. Optical coherence tomography angiography (OCTA) features of PNV are described and interpreted ...

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    8. Morphologic features of basal cell carcinoma using the en-face mode in frequency domain optical coherence tomography

      Morphologic features of basal cell carcinoma using the en-face mode in frequency domain optical coherence tomography

      Background Optical coherence tomography (OCT) has become a valuable non-invasive tool in the in vivo diagnosis of non-melanoma skin cancer, especially of basal cell carcinoma (BCC). Due to an updated software-supported algorithm, a new en-face mode – similar to the horizontal en-face mode in high-definition OCT and reflectance confocal microscopy – surface-parallel imaging is possible which, in combination with the established slice mode of frequency domain (FD-)OCT, may offer additional information in the diagnosis of BCC. Objectives To define characteristic morphologic features of BCC using the new en-face mode in addition to the conventional cross-sectional imaging mode for three-dimensional imaging of ...

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    9. Dermoscopy, confocal microscopy and optical coherence tomography for the diagnosis of bedbug infestation

      Dermoscopy, confocal microscopy and optical coherence tomography for the diagnosis of bedbug infestation

      Letter to the editor: A 33 year-old woman suffering from rosacea presented with outbreaks of itchy plaques on her face and limbs that curiously improved when she was far from home during summer holidays (Fig. 1). Dermoscopy (FotoFinder Systems GmbH, Bad Birnbach, Germany) showed petechiae (Fig. 2A) and reflectance confocal microscopy (RCM; Vivascope 3000 ® , Caliber, New York, USA, distributed in Europe by MAVIG GmbH, München, Germany) showed intraepidermal vesicles (Fig. 2B) suggesting parasite bites. RCM found Demodex folliculorum (Fig. 2C) that could have been responsible for rosacea. However, a careful examination with dermoscopy identified a brown oval-shaped wingless insect ...

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      Mentions: AGFA Healthcare
    10. Anatomical and functional assessment of Tryton bifurcation stent before and after final kissing balloon dilatation: Evaluations by three-dimensional coronary angiography, optical coherence tomography imaging and fractional flow reserve

      Anatomical and functional assessment of Tryton bifurcation stent before and after final kissing balloon dilatation: Evaluations by three-dimensional coronary angiography, optical coherence tomography imaging and fractional flow reserve

      Objectives To assess the anatomical and functional impact of final kissing balloon inflation (FKBI) after implantation of a dedicated bifurcation stent system. Background Current evidence suggests clinical benefit of FKBI in patients undergoing bifurcation dilatation using the Tryton side branch stent (Tryton-SBS). We hypothesized that FKBI improves anatomical reconstruction and functional results of bifurcation treated by Tryton-SBS. Methods An unselected group of patients with complex bifurcation coronary lesions undergoing percutaneous coronary intervention (PCI) with Tryton-SBS underwent paired anatomical assessment with two- and three-dimensional quantitative coronary analysis (2D- and 3D-QCA), and optical coherence tomography (OCT), including 3D reconstruction before and after ...

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    11. Diagnosis of subglottic stenosis in a rabbit model using long-range optical coherence tomography

      Diagnosis of subglottic stenosis in a rabbit model using long-range optical coherence tomography

      Objectives/Hypothesis Current imaging modalities lack the necessary resolution to diagnose subglottic stenosis. The aim of this study was to use optical coherence tomography (OCT) to evaluate nascent subglottic mucosal injury and characterize mucosal thickness and structural changes using texture analysis in a simulated intubation rabbit model. Study Design Prospective animal study in rabbits. Methods Three-centimeter-long sections of endotracheal tubes (ETT) were endoscopically placed in the subglottis and proximal trachea of New Zealand White rabbits (n = 10) and secured via suture. OCT imaging and conventional endoscopic video was performed just prior to ETT segment placement (day 0), immediately after tube ...

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    12. In vivo endoscopic Doppler optical coherence tomography imaging of the colon

      In vivo endoscopic Doppler optical coherence tomography imaging of the colon

      Background and Objective Colorectal cancer (CRC) remains the second deadliest cancer in the United States. Several screening methods exist; however, detection of small polyps remains a challenge. Optical coherence tomography (OCT) has been demonstrated to be capable of detecting lesions as small as 1 mm in the mouse colon, but detection is based on measuring a doubling of the mucosa thickness. The colon microvasculature may be an attractive biomarker of early tumor development because tumor vessels are characterized by irregular structure and dysfunction. Our goal was to develop an endoscopic method of detecting and segmenting colon vessels using Doppler OCT ...

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    13. Markedly different tissue types on optical coherence tomography imaging in a patient with multiple lesion drug-eluting stent in-stent restenosis

      Markedly different tissue types on optical coherence tomography imaging in a patient with multiple lesion drug-eluting stent in-stent restenosis

      The treatment of in-stent restenosis after drug-eluting stent (DES) implantation remains a major clinical challenge. Optical coherence tomography (OCT) imaging at the time of presentation can provide important information on mechanical factors contributing to stent failure as well as on tissue characteristics of the in-stent neointimal tissue. We report a case of markedly different tissue types—characterized by heterogeneous and homogeneous signal intensity—observed in a patient with multiple lesion DES in-stent restenosis. Although both lesions were initially successfully treated with drug-coated balloon angioplasty, the patient presented with recurrent in-stent restenosis in the lesion with homogeneous tissue characteristics. Future studies ...

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    14. Evaluation of circumferential angle closure using iridotrabecular contact index after laser iridotomy by swept-source optical coherence tomography

      Evaluation of circumferential angle closure using iridotrabecular contact index after laser iridotomy by swept-source optical coherence tomography

      Purpose To investigate the quantitative changes of circumferential angle closure after laser iridotomy (LI) using the iridotrabecular contact (ITC) index by Swept-Source optical coherence tomography (OCT). Methods In this prospective observational study conducted in a hospital setting, 42 eyes of 36 patients (five males, 31 females) who underwent LI were included. The mean age was 65.00 ± 8.13 years old and the diagnosis included primary angle closure (PAC, 21 eyes), PAC suspect (16 eyes) and PAC glaucoma (five eyes). Optical coherence tomography (OCT) images were obtained pre-LI and at 1 week post-LI. In each image frame, the scleral spur ...

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    15. In vivo assessment of periodontal structures and measurement of gingival sulcus with Optical Coherence Tomography: a pilot study

      In vivo assessment of periodontal structures and measurement of gingival sulcus with Optical Coherence Tomography: a pilot study

      There has been increasing interest on the development of clinically acceptable, more sensitive and specific methods for non-invasive diagnosis in Periodontics. In this pilot study, the performance of an Optical Coherence Tomography (OCT) system in imaging periodontal structures in humans was evaluated. Gingival sulcus depth measurements were obtained and compared with traditional probes. In total, 445 sites of 23 periodontally healthy individuals were measured by 3 instruments: North Carolina manual probe, Florida automated probe and OCT at 1325 nm. To obtain quantitative measurements from OCT images, the gingival refractive index was also determined. Discomfort/pain perception and the duration of ...

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    16. Astigmatism corrected common path probe for optical coherence tomography

      Astigmatism corrected common path probe for optical coherence tomography

      Background and Objectives Optical coherence tomography (OCT) catheters for intraluminal imaging are subject to various artifacts due to reference-sample arm dispersion imbalances and sample arm beam astigmatism. The goal of this work was to develop a probe that minimizes such artifacts. Materials and Methods Our probe was fabricated using a single mode fiber at the tip of which a glass spacer and graded index objective lens were spliced to achieve the desired focal distance. The signal was reflected using a curved reflector to correct for astigmatism caused by the thin, protective, transparent sheath that surrounds the optics. The probe design ...

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    17. Curvature of iris profile in spectral domain optical coherence tomography and dependency to refraction, age and pupil size – the MIPH Eye&Health Study

      Curvature of iris profile in spectral domain optical coherence tomography and dependency to refraction, age and pupil size – the MIPH Eye&Health Study

      Purpose Optical coherence tomography (OCT) of the anterior segment allows quantitative analysis of the geometry of the iris. We performed spectral domain OCT examinations in healthy emmetropic, hyperopic and myopic subjects to investigate iris curvature and its associations. Methods In a cross-sectional study, out of 4617 eyes (2309 subjects) those with refractive errors of <−4 or >+3 dioptres were identified by objective refraction. The iris was examined using the anterior segment mode of a spectral domain 3D OCT-2000 (Topcon Inc., Japan) in the temporal meridian, and OCT scans were investigated with respect to presence and amount of convex and concave ...

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