1. 1-24 of 431 1 2 3 4 ... 16 17 18 »
    1. Collateral damage to the ureter and Nitinol stone baskets during thulium fiber laser lithotripsy

      Collateral damage to the ureter and Nitinol stone baskets during thulium fiber laser lithotripsy

      Background The experimental Thulium fiber laser (TFL) is currently being studied as a potential alternative lithotripter to the clinical gold standard Holmium:YAG laser. Safety studies characterizing undesirable Holmium:YAG laser-induced damage to ureter tissue and stone baskets have been previously reported. Similarly, this study characterizes TFL induced ureter and stone basket damage. Methods A TFL beam with energy of 35 mJ per pulse, pulse duration of 500 µs, and variable pulse rates of 50–500 Hz, was delivered through 100-µm-core optical fibers, to either porcine ureter wall, in vitro , or a standard 1.9-Fr Nitinol stone basket wire ...

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    2. Dimensional metrology of lab-on-a-chip internal structures: a comparison of optical coherence tomography with confocal fluorescence microscopy

      Dimensional metrology of lab-on-a-chip internal structures: a comparison of optical coherence tomography with confocal fluorescence microscopy

      Summary The characterization of internal structures in a polymeric microfluidic device, especially of a final product, will require a different set of optical metrology tools than those traditionally used for microelectronic devices. We demonstrate that optical coherence tomography (OCT) imaging is a promising technique to characterize the internal structures of poly(methyl methacrylate) devices where the subsurface structures often cannot be imaged by conventional wide field optical microscopy. The structural details of channels in the devices were imaged with OCT and analyzed with an in-house written ImageJ macro in an effort to identify the structural details of the channel. The ...

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    3. In vivo blood flow imaging of inflammatory human skin induced by tape stripping using optical microangiography

      In vivo blood flow imaging of inflammatory human skin induced by tape stripping using optical microangiography

      Vasculature response is a hallmark for most inflammatory skin disorders. Tape stripping on human skin causes a minor inflammation which leads to changes in microvasculature. In this study, optical microangiography (OMAG), noninvasive volumetric microvasculature in vivo imaging method, has been used to track the vascular responses after tape stripping. Vessel density has been quantified and used to correlate with the degree of skin irritation. The proved capability of OMAG technique in visualizing the microvasculature network under inflamed skin condition can play an important role in clinical trials of treatment and diagnosis of inflammatory skin disorders.

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    4. Healing indicators after pterygium excision by optical coherence tomography

      Healing indicators after pterygium excision by optical coherence tomography

      Purpose To establish the sequence of tomographic changes in the tissue recovery process after pterygium excision and to propose healing indicators. Methods Optical coherence tomography (OCT) images were taken at 1 week, 1, 3 and 6 months after lesion excision in 73 eyes of 73 patients (33 male, 40 female; mean age 50, S.D. 5.0, range 40–70 years) with primary nasal pterygium. Biomicroscopy was performed at each visit and at 12 months, to diagnose clinical healing or lesion recurrence. The presence of well demarcated corneal epithelium, conjunctival epithelium, limbal demarcation area, and graft thickening were analysed. Comparisons ...

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    5. Functional optical coherence tomography of pigmented lesions

      Functional optical coherence tomography of pigmented lesions

      Background Cutaneous melanomas are diagnosed worldwide in 231 130 patients per year. The sensitivity and specificity of melanoma diagnosis expresses the need for an additional diagnostic method. Optical coherence tomography (OCT) has shown that it allows morphological (qualitative) description of image features and quantitative analysis of pathology related light scattering by means of the attenuation coefficient (μ oct ). Objective We hypothesize that OCT images of nevi will differ qualitatively and quantitatively from melanomas. Methods Forty lesions from 33 consecutive patients were imaged with OCT. After data acquisition, excision was performed. Epidermal layer thickness was measured and values of μ oct were extracted ...

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    6. Ex vivo investigations on the potential of optical coherence tomography (OCT) as a diagnostic tool for reproductive medicine in a bovine model

      Ex vivo investigations on the potential of optical coherence tomography (OCT) as a diagnostic tool for reproductive medicine in a bovine model

      Comparative visualization of ex vivo bovine testicular tissue by the Telesto TM microscopic optical coherence tomography system (left) and corresponding H&E staining (right). Routine infertility investigations in the male and female include imaging techniques such as ultrasonography and endoscopy (fertiloscopy). However, these techniques lack the resolution to localize vital sperm or to reveal detailed morphological analysis of the oviduct which is often the cause of infertility in females. Therefore we set out to evaluate the efficiency of optical coherence tomography (OCT) as a diagnostic imaging tool for micron-scale visualization of the male and female genital tract. Using the bovine ...

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    7. Time-resolved Biofilm Deformation Measurements using Optical Coherence Tomography

      Time-resolved Biofilm Deformation Measurements using Optical Coherence Tomography

      The interaction of shear stress with the biofilm leads to a dynamic deformation, which is related to the structural and material characteristics of biofilms. We show how optical coherence tomography can be used as an imaging technique to investigate the time-resolved deformation on the biofilm mesoscale as well as to estimate mechanical properties of the biofilm. For the first time time-resolved deformation from cross-sectional views of the inner biofilm structure could be shown. Changes in the biofilm structure and rheological properties were calculated from cross sections in real time and time-lapsed measurements. Heterotrophic biofilms were grown in a flow cell ...

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    8. In vivo real-time imaging of airway dynamics during bronchial challenge test

      In vivo real-time imaging of airway dynamics during bronchial challenge test

      Background and Objective Asthmatic patients exhibit airway hyper-responsiveness, which induces bronchoconstriction and results in a ventilation defect. The bronchial challenge test using methacholine is a useful way to measure airway hyper-responsiveness with airway constriction. Anatomical optical coherence tomography has been used to image airway hyper-responsiveness of medium sized bronchus with the aid of an endoscopic probe. Recently, a thoracic window was reported that allows direct visualization of terminal airway such as alveolus. A multi-scale integrated airway dynamics was assessed in this study. We imaged in vivo changes in the right intermedius bronchus and alveolar structure during the bronchial challenge test ...

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    9. Advances in non-invasive techniques as aids to the diagnosis and monitoring of therapeutic response in plaque psoriasis: a review

      Advances in non-invasive techniques as aids to the diagnosis and monitoring of therapeutic response in plaque psoriasis: a review

      Plaque psoriasis is a common, chronic, inflammatory disease with a multifactorial etiopathogenesis. Although its diagnosis is often based on clinical features, in ambiguous cases a biopsy with histopathologic confirmation may be necessary. Advanced high-definition imaging techniques may be useful in the study of skin properties in vivo and may facilitate therapeutic monitoring. Available imaging tools vary in their resolution, depth of penetration and visual representation (horizontal, vertical, three-dimensional), and in the type of skin structures visualized. The purpose of this review is to analyze a variety of non-invasive techniques that may assist in establishing definitive diagnoses, as well as in ...

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    10. Non-invasive diagnosis of sweat gland dysplasia using optical coherence tomography and reflectance confocal microscopy in a family with anhidrotic ectodermal dysplasia (Christ-Siemens-Touraine syndrome

      Non-invasive diagnosis of sweat gland dysplasia using optical coherence tomography and reflectance confocal microscopy in a family with anhidrotic ectodermal dysplasia (Christ-Siemens-Touraine syndrome

      Background Anhidrotic ectodermal dysplasia (AED) is an inherited syndrome, which originates mainly from genetic alteration of the ectodysplasin A (EDA) gene. It regularly affects the adnexa of the skin which results in a characteristic phenotype of the patients including hypo- or anhidrosis leading to severe disturbances in the regulation of body temperature. Objectives To prevent the development of the symptoms in early childhood promising therapeutic approaches are currently under clinical investigation. In this context, timely diagnosis of this genetic syndrome is crucial. The purpose of our study was the investigation of modern non-invasive imaging methods such as optical coherence tomography ...

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    11. Microperimetric assessment of the two OCT subtypes of acute macular neuroretinopathy

      Microperimetric assessment of the two OCT subtypes of acute macular neuroretinopathy

      Background To evaluate the morpho-functional alterations associated with Acute Macular Neuroretinopathy (AMNR). Design Prospective observational case series study carried out at the University Vita-Salute, Scientific Institute San Raffaele. Participants Five out of 6 eyes (three patients) showed the typical features of AMNR. Methods The patients underwent an ophthalmological examination, including best-corrected visual acuity (BCVA) measurement, electroretinogram and electroculogram (ERG/EOG), multifocal electroretinogram (mfERG), infrared reflectance, short-wavelength and near-infrared-FAF (SW-FAF/NIR-FAF), spectral-domain optical coherence tomography (SD-OCT) and microperimetry. Main Outcome Measure Microperimetric alterations in the two SD-OCT subtypes of AMNR. Results The BCVA was 20/20 in all patients. ERG and ...

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    12. Quantitative and rapid estimations of human sub-surface skin mass using ultra-high-resolution spectral domain optical coherence tomography

      Quantitative and rapid estimations of human sub-surface skin mass using ultra-high-resolution spectral domain optical coherence tomography

      In vivo optical coherence tomography (OCT) image of angioma (A). Thin red arrows point to a blood vessel (BV). Non-invasive and quantitative estimations for the delineation of sub-surface tumor margins could greatly aid in the early detection and monitoring of the morphological appearances of tumor growth, ensure complete tumor excision without the unnecessary sacrifice of healthy tissue, and facilitate post-operative follow-up for recurrence. In this study, a high-speed, non-invasive, and ultra-high-resolution spectral domain optical coherence tomography (UHR-SDOCT) imaging platform was developed for the quantitative measurement of human sub-surface skin mass. With a proposed robust, semi-automatic analysis, the system can rapidly ...

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    13. Macular thickness assessed with spectral domain OCT in a population-based study of children: normative data, repeatability and reproducibility and comparison with time domain OCT

      Macular thickness assessed with spectral domain OCT in a population-based study of children: normative data, repeatability and reproducibility and comparison with time domain OCT

      Purpose To collect data on macular thickness assessed with Cirrus OCT in healthy children in a population-based study, to examine the repeatability and reproducibility, and to compare the values with Stratus OCT. Methods Fifty-eight 6- to 15-year-old children, born at term, were examined. Best-corrected visual acuity and refraction were assessed. One examiner performed three OCT assessments, and the repeatability was calculated. Thereafter, a second examiner repeated the examinations to calculate the reproducibility. One eye was randomized to be included in the normal material. Finally, the second examiner assessed the macular thickness with the Stratus OCT. Results The mean value (±SD ...

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    14. High resolution imaging of acne lesion development and scarring in human facial skin using OCT-based microangiography

      High resolution imaging of acne lesion development and scarring in human facial skin using OCT-based microangiography

      Background and Objective Acne is a common skin disease that often leads to scarring. Collagen and other tissue damage from the inflammation of acne give rise to permanent skin texture and microvascular changes. In this study, we demonstrate the capabilities of optical coherence tomography-based microangiography in detecting high-resolution, three-dimensional structural, and microvascular features of in vivo human facial skin during acne lesion initiation and scar development. Materials and Methods A real time swept source optical coherence tomography system is used in this study to acquire volumetric images of human skin. The system operates on a central wavelength of 1,310 ...

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    15. High-definition optical coherence tomography algorithm for discrimination of basal cell carcinoma from clinical BCC imitators and differentiation between common subtypes

      High-definition optical coherence tomography algorithm for discrimination of basal cell carcinoma from clinical BCC imitators and differentiation between common subtypes

      Background Preliminary studies have described morphological features of basal cell carcinoma (BCC) imaged by high-definition optical coherence tomography (HD-OCT) and suggested that this technique may aid in its diagnosis and management. However, systematic studies evaluating the accuracy of HD-OCT for the diagnosis of BCC are lacking. Objective The aim of this study was to identify three-dimensional (3-D) HD-OCT features able i) to distinguish BCC from clinical BCC imitators and ii) to discriminate between the most common BCC subtypes. Based on these particular features, a diagnostic algorithm will be suggested. Method A total of 50 histopathologically confirmed BCCs (18 superficial, 19 ...

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    16. Recellularising of human acellular dermal matrices imaged by high-definition optical coherence tomography

      Recellularising of human acellular dermal matrices imaged by high-definition optical coherence tomography

      Background High-definition optical coherence tomography (HD-OCT) permits real-time 3-D imaging of the impact of selected agents on human skin allografts. Objective The real-time 3-D HD-OCT assessment of i) the impact on morphological and cellular characteristics of the processing of human acellular dermal matrices (HADMs) and ii) repopulation of HADMs in vitro by human fibroblasts and remodelling of the extracellular matrix by these cells. Method Four different skin decellularisation methods, Dispase II/Triton X-100, Dispase II/SDS (sodium dodecyl sulphate), NaCl/Triton X-100 and NaCl/SDS, were analyzed by HD-OCT. HD-OCT features of epidermal removal, dermo-epidermal junction (DEJ) integrity, cellularity and ...

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    17. In Vivo Characterization of Carotid Neointimal Hyperplasia by use of Optical Coherence Tomography: Before and After Cutting Balloon Angioplasty

      In Vivo Characterization of Carotid Neointimal Hyperplasia by use of Optical Coherence Tomography: Before and After Cutting Balloon Angioplasty

      Optical coherence tomography (OCT) is a modern intravascular imaging modality that has the capability to provide detailed, in vivo characterization of the arterial wall and atherosclerotic plaque. The current understanding of the appearance of atherosclerotic plaque via OCT is largely based on coronary arterial studies where OCT information has been employed to guide therapeutic management and permits the immediate evaluation of percutaneous intervention. The clinical success of OCT in the coronary arteries has laid the foundation for investigation of the carotid artery and thus, stroke risk assessment. We report the novel use of OCT for tissue characterization of severe stenosis ...

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    18. Intravascular magnetomotive optical coherence tomography of targeted early-stage atherosclerotic changes in ex vivo hyperlipidemic rabbit aortas

      Intravascular magnetomotive optical coherence tomography of targeted early-stage atherosclerotic changes in ex vivo hyperlipidemic rabbit aortas

      Representative magnetomotive signal (green) using targeted and non-targeted magnetomotive microspheres in atherosclerotic diseased rabbit aortas. We report the development of an intravascular magnetomotive optical coherence tomography (IV-MM-OCT) system used with targeted protein microspheres to detect early-stage atherosclerotic fatty streaks/plaques. Magnetic microspheres (MSs) were injected in vivo in rabbits, and after 30 minutes of in vivo circulation, excised ex vivo rabbit aorta samples specimens were then imaged ex vivo with our prototype IV-MM-OCT system. The alternating magnetic field gradient was provided by a unique pair of external custom-built electromagnetic coils that modulated the targeted magnetic MSs. The results showed a ...

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    19. In vivo evaluation of the cornea and conjunctiva of the normal laboratory beagle using time- and Fourier-domain optical coherence tomography and ultrasound pachymetry

      In vivo evaluation of the cornea and conjunctiva of the normal laboratory beagle using time- and Fourier-domain optical coherence tomography and ultrasound pachymetry

      Objective To obtain normative data for the canine cornea and conjunctiva using high-resolution time- and Fourier-domain optical coherence tomography (TD-OCT and FD-OCT) and ultrasound pachymetry (USP). Animals One hundred sixty-eight eyes of 133 healthy young intact laboratory beagles. Procedures The cornea and conjunctiva of 16 eyes of 8 healthy young intact female beagles were imaged using FD-OCT. Corneal thickness was measured with FD-OCT and USP, while corneal epithelial thickness and conjunctival epithelial thickness were measured with FD-OCT. The central corneal thickness (CCT) was determined in 152 eyes of 125 healthy young adult intact female (35) and male (90) beagles using ...

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    20. High-definition optical coherence tomography algorithm for the discrimination of actinic keratosis from normal skin and from squamous cell carcinoma

      High-definition optical coherence tomography algorithm for the discrimination of actinic keratosis from normal skin and from squamous cell carcinoma

      Background Preliminary studies described morphological features of actinic keratosis (AK) and squamous cell carcinoma (SCC) imaged by High-Definition Optical Coherence Tomography (HD-OCT) and suggested that this technique may aid in their diagnosis. However, systematic studies evaluating the accuracy of HD-OCT for the diagnosis of AK and SCC are lacking so far. Objective In this study, we sought to design an algorithm for AK classification that could (i) distinguish SCC from AK and normal skin, (ii) differentiate AK from normal skin and (iii) discriminate AKs with adnexal involvement from those without. Methods A total of 53 histopathologically confirmed lesions (37 AKs ...

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    1-24 of 431 1 2 3 4 ... 16 17 18 »
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