1. 1-24 of 425 1 2 3 4 ... 16 17 18 »
    1. 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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    2. 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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    3. 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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    4. 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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    5. 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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    6. 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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    7. 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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    8. 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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    9. 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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    10. 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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    11. 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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    12. 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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    13. 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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    14. 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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    15. 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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    16. 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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    17. Three-dimensional Imaging and Analysis of Human Cartilage Degeneration Using Optical Coherence Tomography

      Three-dimensional Imaging and Analysis of Human Cartilage Degeneration Using Optical Coherence Tomography

      Optical Coherence Tomography (OCT) is an evolving imaging technology allowing non-destructive imaging of cartilage tissue at near-histological resolution. This study investigated the diagnostic value of real time 3-D OCT in comparison to conventional 2-D OCT in the comprehensive grading of human cartilage degeneration. Fifty-three human osteochondral samples were obtained from eight total knee arthroplasties. OCT imaging was performed by either obtaining a single two-dimensional cross-sectional image ( 2-D OCT ) or by collecting 100 consecutive parallel 2-D OCT images to generate a volumetric data set of 8 mm X 8 mm (3-D OCT ). OCT images were assessed qualitatively according to a modified ...

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    18. Assessment of a scoring system for Basal Cell Carcinoma with multi-beam optical coherence tomography

      Assessment of a scoring system for Basal Cell Carcinoma with multi-beam optical coherence tomography

      Background Multi-beam optical coherence tomography (OCT) is a novel method of non-invasive skin imaging allowing the evaluation of tissue at high level of lateral and axial resolution. It permits the horizontal and vertical evaluation of the extent of diseases. Objective Herein, we aimed to validate diagnosing basal cell carcinoma (BCC) by OCT using a newly developed scoring system (‘Berlin Score’-BS). This was based on the predetermined criteria such as dark border underneath the tumour and ovoid structures. Their frequency and distribution in subtypes of BCC were evaluated. Methods The study was conducted in two phases, in which the experience ...

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    19. First-in-Man study evaluating the safety and efficacy of a second generation biodegradable polymer sirolimus-eluting stent in the treatment of patients with de novo coronary lesions: Clinical, angiographic, and OCT outcomes of CREDIT-1

      First-in-Man study evaluating the safety and efficacy of a second generation biodegradable polymer sirolimus-eluting stent in the treatment of patients with de novo coronary lesions: Clinical, angiographic, and OCT outcomes of CREDIT-1

      Objective: To evaluate the preliminary safety and efficacy of the EXCEL II stent system. Background: Although the first biodegradable polymer drug-eluting stent (BP-DES), EXCEL, was launched nearly a decade ago, in-stent restenosis and stent thrombosis remain pertinent clinical problems in practice. A new cobalt-chromium BP-DES EXCEL II has been developed with the aim of improving stent safety and efficacy. Methods: Forty-five patients with single de novo native coronary lesions were enrolled and randomized to two groups in a 2:1 ratio, the 4-month follow-up group (n=30) and the 12-month follow-up group (n=15). All patients underwent percutaneous coronary intervention ...

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    20. Optical coherence tomography vs intravascular ultrasound in the evaluation of observer variability and reliability in the assessment of stent deployment: The OCTIVUS Study

      Optical coherence tomography vs intravascular ultrasound in the evaluation of observer variability and reliability in the assessment of stent deployment: The OCTIVUS Study

      Abstract Objectives : To compare the variability in the assessment of coronary stents among interventional cardiologists (readers) using Optical Coherence Tomography (OCT) and Intravascular ultrasound (IVUS). Background : IVUS is established and validated in the evaluation of coronary stent. For cardiologists without core lab expertise, the utility of IVUS is limited by image quality. OCT yields higher image resolution, however, the consistency with which these readers interpret OCT images has not been fully evaluated or compared with IVUS. Methods : OCT and IVUS image sets (5 pairs) obtained following stent placement were reviewed by readers with clinical experience with both modalities. Parameters assessed ...

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    21. Impact of coronary artery stent edge dissections on long-term clinical outcome in patients with acute coronary syndrome: An Optical Coherence Tomography Study

      Impact of coronary artery stent edge dissections on long-term clinical outcome in patients with acute coronary syndrome: An Optical Coherence Tomography Study

      Aims: The purpose of the present study was to assess the incidence, predictors and long term prognosis of stent edge dissections identified by (OCT) after the implantation of bare metal (BMS) and drug eluting stents (DES). Methods and results: We studied 74 patients who underwent percutaneous coronary intervention (PCI) because of an acute coronary syndrome. Edge dissections were found in 29 of 74 patients (39.1%). Independent predictors of edge dissections were: the presence of ST-elevation myocardial infarction (STEMI) (p=0.005, odds ratio 11.78; 95% Cl 2.06-67.10), the small reference lumen diameter ( p= 0.009, odds ...

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    22. Noninvasive depth-resolved optical measurements of the tympanic membrane and middle ear for differentiating otitis media

      Noninvasive depth-resolved optical measurements of the tympanic membrane and middle ear for differentiating otitis media

      Objective/Hypothesis In this study, optical coherence tomography (OCT) is used to noninvasively and quantitatively determine tympanic membrane (TM) thickness and the presence and thickness of any middle-ear biofilm located behind the TM. These new metrics offer the potential to differentiate normal, acute, and chronic otitis media (OM) infections in pediatric subjects. Study Design Case series with comparison group. Methods The TM thickness of 34 pediatric subjects was acquired using a custom-built, handheld OCT system following a traditional otoscopic ear exam. Results Overall thickness (TM and any associated biofilm) was shown to be statistically different for normal, acute, and chronic ...

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    1-24 of 425 1 2 3 4 ... 16 17 18 »
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