1. 1-24 of 371 1 2 3 4 ... 14 15 16 »
    1. Novel optical coherence tomography classification of torpedo maculopathy

      Novel optical coherence tomography classification of torpedo maculopathy

      Background Torpedo maculopathy is a rare condition with a twofold clinical significance. Firstly, it is a differential of atypical congenital hypertrophy of the retinal pigment epithelium. Secondly, visual field loss has been reported. We demonstrate the spectrum of structural abnormality of torpedo maculopathy as seen on optical coherence tomography, and correlate this with age of presentation, fundus autofluorescence, retinal sensitivity loss and visual field abnormality. Design A retrospective, observational case series. Participants Five Australian patients seen between 2008 and 2013. Methods Fundus photography, optical coherence tomography, fundus autofluorescence and visual field analysis. One patient underwent fluorescein angiography. Main Outcome Measures ...

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    2. Endoscopy for diagnosis and treatment in esophageal cancers: high-technology assessment

      Endoscopy for diagnosis and treatment in esophageal cancers: high-technology assessment

      The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the endoscopic tools to recognize squamous cell dysplasia; confocal laser endomicroscopy for Barrett's esophagus; confocal microscopy in the cancer patient; optical coherence tomography in the assessment of subsquamous Barrett's metaplasia; endoscopic mucosal resection for high-grade dysplasia in Barrett's esophagus; HALO in the treatment of squamous dysplasia; and the use of fluorescence in situ hybridization to detect dysplasia and adenocarcinoma in patients with Barrett's esophagus.

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    3. High-definition optical coherence tomography of melanocytic skin lesions

      High-definition optical coherence tomography of melanocytic skin lesions

      High-definition optical coherence tomography and the corresponding vertically sectioned histology of a compound naevus. High-definition optical coherence tomography (HD-OCT) scanners have recently been developed. We assessed micromorphological HD-OCT correlates of benign naevi (BN) and malignant melanoma (MM). 28 BN and 20 MM were studied using HD-OCT and histology. Epidermal honeycomb/cobblestone pattern, regular junctional cell nests, and edged papillae are more often observed in BN, whereas fusion of rete ridges, pagetoid cells and junctional and/or dermal nests with atypical cells are more frequently seen in MM. A high overlap of HD-OCT features in BN and MM was observed and ...

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    4. Differences determined by optical coherence tomography volumetric analysis in non-culprit lesion morphology and inflammation in ST-segment elevation myocardial infarction and stable angina pectoris patients

      Differences determined by optical coherence tomography volumetric analysis in non-culprit lesion morphology and inflammation in ST-segment elevation myocardial infarction and stable angina pectoris patients

      Background: While the current methodology for determining fibrous cap (FC) thickness of lipid plaques is based on manual measurements of arbitrary points, which could lead to high variability and decreased accuracy, it ignores the three-dimensional (3-D) morphology of coronary artery disease. Objective: To compare, utilizing optical coherence tomography (OCT) assessments, volumetric quantification of FC and macrophage detection using both visual assessment and automated image processing algorithms in non-culprit lesions of STEMI and stable angina pectoris (SAP) patients. Methods: Lipid plaques were selected from 67 consecutive patients (1 artery/patient). FC was manually delineated by a computer-aided method and automatically classified ...

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    5. Imaging of collagen deposition disorders using optical coherence tomography

      Imaging of collagen deposition disorders using optical coherence tomography

      Background Collagen deposition disorders such as hypertrophic scars, keloids and scleroderma can be associated with significant stigma and embarrassment. These disorders often constitute considerable impairment to quality of life, with treatment posing to be a substantial challenge. Optical coherence tomography (OCT) provides a non-invasive, easily applicable bedside optical imaging method for assessment of the skin. It is hypothesized that OCT imaging may be useful in assessing fibrosis to avoid additional biopsies that could potentially worsen the scarring. Method Thirty-three patients with ordinary scars, hypertrophic scars, keloid scarring, lichen sclerosus et atrophicus and localized or systemic scleroderma were recruited for this ...

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    6. Using Optical Coherence Tomography to Examine Additives in Chinese Song Jun Glaze

      Using Optical Coherence Tomography to Examine Additives in Chinese Song Jun Glaze

      We use optical coherence tomography (OCT) to acquire microstructure images of Chinese Song Jun glaze to reveal the copper and quartz additives used and, in two typical samples, we show that the amount added is considerable. Focusing on these two additives, including the species, amount and granule (particle) size added in the glaze, the objective of the present study is to explore how they functioned in relation to the Jun glaze's visual characteristics, opalescence and sky-blue colour, attributed to the unique liquid–liquid phase separation that occurs in Jun glaze.

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    7. 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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    8. Megalopapilla in children: a spectral domain optical coherence tomography analysis

      Megalopapilla in children: a spectral domain optical coherence tomography analysis

      Purpose To compare various optic nerve head (ONH) parameters and peripapillary retinal nerve fibre layer (pRNFL) thickness between megalopapilla cases and normal control using spectral domain optical coherence tomography (SD-OCT) in children. Methods Fifty eyes with megalopapilla and 80 normal control eyes of totally 130 children between the ages of 6 and 15 were examined using SD-OCT. Optic nerve head parameters including disc diameter, cup-to-disc ratio, disc area, cup area, rim area, cup volume and rim volume, and pRNFL thickness were analysed and compared between two groups. Results Megalopapilla group presented larger optic disc diameter, disc and cup area, cup-to-disc ...

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    9. Optical coherence tomography-based predictors for creatine kinase-myocardial band elevation after elective percutaneous coronary intervention for in-stent restenosis

      Optical coherence tomography-based predictors for creatine kinase-myocardial band elevation after elective percutaneous coronary intervention for in-stent restenosis

      Objectives We evaluated whether morphological characteristics of neointimal tissue of in-stent restenosis (ISR) lesions assessed by optical coherence tomography (OCT) affect periprocedural elevation of creatine kinase-myocardial band (CK-MB). Background The impact of neointimal characteristics of ISR lesions on periprocedural myocardial injury has not been sufficiently investigated. Methods A total of 125 patients with ISR lesions underwent elective percutaneous coronary intervention (PCI) and pre-PCI OCT examination. Measurements of CK-MB were performed upon hospitalization, before PCI, and every 8 hr for 24 hr after PCI. CK-MB elevation was defined as levels above the 99th percentile of the upper reference limit. Neoatherosclerosis was ...

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    10. A survey of current and anticipated use of standard and specialist equipment by UK optometrists

      A survey of current and anticipated use of standard and specialist equipment by UK optometrists

      Purpose To investigate current and anticipated use of equipment and information technology (IT) in community optometric practice in the UK, and to elicit optometrists' views on adoption of specialist equipment and IT. Methods An anonymous online questionnaire was developed, covering use of standard and specialist diagnostic equipment, and IT. The survey was distributed to a random sample of 1300 UK College of Optometrists members. Results Four hundred and thirty-two responses were received (response rate = 35%). Enhanced (locally commissioned) or additional/separately contracted services were provided by 73% of respondents. Services included glaucoma repeat measures (30% of respondents), glaucoma referral refinement ...

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    11. Evaluation of two quantitative analysis methods of optical coherence tomography for detection of enamel demineralization and comparison with microhardness

      Evaluation of two quantitative analysis methods of optical coherence tomography for detection of enamel demineralization and comparison with microhardness

      Background and Objective We aimed to evaluate in the same study two quantitative methods for quantification of incipient caries in human dental enamel by using optical coherence tomography (OCT): the optical attenuation coefficient and the area under the A-scan signal, and to compare their results with those obtained from microhardness analysis. Study Design/Materials and Methods One hundred and sixty samples were obtained from 40 sound human third molars, which had their crowns sectioned. Simulated caries were created by a pH cycling method. OCT measurements were performed on the samples, before and after the induced demineralization. We determined the total ...

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    12. New Insights on acute expansion and longitudinal elongation of bioresorbable vascular scaffolds In-Vivo and at bench test: A note of caution on reliance to compliance charts and nominal length

      New Insights on acute expansion and longitudinal elongation of bioresorbable vascular scaffolds In-Vivo and at bench test: A note of caution on reliance to compliance charts and nominal length

      Objectives : We performed systematic optical coherence tomography (OCT) analyses after BVS implantation in a “real world” setting aiming at evaluating scaffold expansion and longitudinal integrity. Background : A comprehensive elucidation of bioresorbable vascular scaffolds´ (BVS) acute performance in the “real-world” setting is lacking Methods : Acute BVS expansion compared with compliance chart information and longitudinal integrity were assessed in 29 patients (32 lesions) by OCT. In addition, bench experiments with 4 scaffolds were performed with different combinations of deployment pressures and tube stiffness. Results : Scaffold underexpansion, using compliance chart information as reference, was observed in 97% of OCT cross-sections in vivo; however ...

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    13. Dynamic dark-light changes in anterior chamber and iris parameters in angle closure patients with novel automatic algorithm using anterior segment optical coherence tomography (AS-OCT)

      Dynamic dark-light changes in anterior chamber and iris parameters in angle closure patients with novel automatic algorithm using anterior segment optical coherence tomography (AS-OCT)

      Purpose To describe the dynamic dark-light changes in anterior chamber (AC) measurements and iris parameters in angle closure patients compared to normal angle patients using a fully automatic algorithm developed for anterior segment optical coherence tomography (AS-OCT). Methods 10 patients (17 eyes with closed angles) and 8 patients (15 eyes with normal angles) on gonioscopic grading were recruited. We acquired images in both dark and light conditions using Visante OCT. Custom software analyzed the images using the iris rim as the landmark instead of the sclera spur. The parameters analyzed included angle opening distance and angle recess area, at 750 ...

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    14. Swept source optical coherence tomography artifacts in glaucoma patients

      Swept source optical coherence tomography artifacts in glaucoma patients

      Purpose To demonstrate the frequency and the type of swept-source optical coherence tomography (SS –OCT) imaging artifacts in patients being evaluated glaucoma and to present common artifacts examples Methods The SS–OCT images of 101 glaucoma suspect and glaucoma patients were used to evaluate image artifacts. We used a 3 dimensional imaging data set of 6x6mm raster scan centered on the optic disc (3D disc scan) and a 3 dimensional imaging data set of 12 mm horizontal line scan centered between optic disc and the fovea (3D side scan). For each scan, both printout report and the source image of ...

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    15. Test-retest reliability on measuring anterior chamber parameters with a novel automatic algorithm using anterior segment optical coherence tomography

      Test-retest reliability on measuring anterior chamber parameters with a novel automatic algorithm using anterior segment optical coherence tomography

      Purpose To describe the test-retest variability in anterior chamber and iris parameters obtained on anterior segment optical coherence tomography (AS-OCT) when measured with a novel automatic Location-Based Graph Search segmentation algorithm. Methods Patients with open angles and primary angle closure on gonioscopic finding were invited for anterior chamber (AC) angle imaging with the Visante AS-OCT. 3 scans of each eye were acquired in darkness with the patients repositioning their heads after each scan. The images were analysed with a custom software which used the iris rim as the landmark instead of the sclera spur. The parameters analyzed included angle opening ...

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    16. The choroid profiles at the posterior pole measured by enhanced depth imaging optical coherence tomography in healthy Korean children

      The choroid profiles at the posterior pole measured by enhanced depth imaging optical coherence tomography in healthy Korean children

      Purpose To assess the changes of the choroidal thickness in healthy Korean Children using enhanced depth imaging (EDI) optical coherence tomography (OCT) and to evaluate the association of choroidal thickness and axial length. Methods Seventy-nine eyes (79 children) with cycloplegic refractive errors within ± 1diopter spherical equivalent underwent horizontal scan using EDI OCT. The choroidal thickness was the vertical distance between the posterior edge of the retinal pigment epithelium and the inner scleral border at 1mm intervals from 3mm nasal and 4mm temporal to the fovea using the manual caliper provided by the software of the device. Axial length was examined ...

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    17. Compressive chiasmal lesions: optical coherence tomography, ganglion cell and inner plexiform layers and visual field tests

      Compressive chiasmal lesions: optical coherence tomography, ganglion cell and inner plexiform layers and visual field tests

      Purpose The authors present an analysis of the automated macular ganglion cell complex measurements in patients with compressive chasmal lesions. Methods Observational study of 20 eyes of 20 patients with compressive chiasmal lesions followed at the neurophthalmology outpatient clinic. Optical Coherence Tomography (OCT SPECTRALIS® - Heidelberg Engineering GmbH) was performed and high-resolution macular scans were obtained. Ganglion cell layer and inner plexiform layer (GCL+IPL) average thickness and retinal nerve fiber layer (RNFL) thickness were also determined. A functional evaluation was performed with Static Computerized Perimetry (Octopus Perimetry®, Haag-Streit). Statistical analysis was done with SPSS Statistics. A p value < 0.05 ...

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    18. Choroidal thickness and volume in healthy children messured by enhanced depth imaging optical coherence tomography

      Choroidal thickness and volume in healthy children messured by enhanced depth imaging optical coherence tomography

      Purpose To evaluate choroidal thickness during childhood using enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD-OCT), and its correlation with age, sex, axial length (AL) and refractive error (RE) Methods Cross-sectional study in which 93 eyes of 93 healthy children were studied using a 25 A-scans-EDI SD-OCT protocol. Choroidal thickness was segmented manually, and an ETDRS grid was applied to analyze choroidal thickness and volume in each of its nine sectors. Two observers independently studied 30 children to assess repeatability and reproducibility, using intraclass coefficient (ICC). Results We included 50 males and 43 females, with mean age of 9 ...

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    19. A method for monitoring enamel erosion using laser irradiated surfaces and optical coherence tomography

      A method for monitoring enamel erosion using laser irradiated surfaces and optical coherence tomography

      Introduction Since optical coherence tomography (OCT) is well suited for measuring small dimensional changes on tooth surfaces, OCT has great potential for monitoring tooth erosion. Previous studies have shown that enamel areas ablated by a carbon dioxide laser manifested lower rates of erosion compared to the non-ablated areas. The purpose of this study was to develop a model to monitor erosion in vitro that could potentially be used in vivo . Methods Thirteen bovine enamel blocks were used in this in vitro study. Each 10 mm × 2 mm block was partitioned into five regions, the central region was unprotected, the adjacent ...

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    20. Bivalirudin versus unfractionated heparin for residual thrombus burden: A frequency-domain optical coherence tomography study

      Bivalirudin versus unfractionated heparin for residual thrombus burden: A frequency-domain optical coherence tomography study

      Objectives: This study aimed to compare the effect of bivalirudin and unfractionated heparin (UFH) on residual thrombus burden assessed by frequency-domain optical coherence tomography (FD-OCT), and on angiographic indices of microvascular obstruction (MVO). Background: The efficacy of bivalirudin to inhibit thrombus formation inside the stent during percutaneous coronary interventions (PCI) as compared to UFH is unknown. Methods: Sixty patients with coronary artery disease who underwent post-PCI FD-OCT were studied, including 20 patients treated with bivalirudin and 40 control patients treated with UFH, matched by clinical presentation, stent characteristics, and periprocedural medications. In-stent thrombus volume, thrombus score (number of quadrants with ...

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    21. Retinal nerve fibre layer thickness measurements by optical coherence tomography in patients with sleep apnoea syndrome

      Retinal nerve fibre layer thickness measurements by optical coherence tomography in patients with sleep apnoea syndrome

      Background The study aims to investigate whether retinal nerve fibre layer (RNFL) abnormalities can be detected in patients with obstructive sleep apnoea/hypopnoea syndrome with normally appearing optic disc. Design This is an observational case-control study. Participants One hundred and eight consecutive patients with moderate or severe obstructive sleep apnoea/hypopnoea syndrome (OSAHS) as determined by overnight polysomnography and normal looking discs and 108 age-matched healthy controls were included in the study. Methods All patients underwent RNFL examinations by optical coherence tomography using fast retinal nerve fibre layer thickness scan. Main Outcome Measures The main outcome measure was RNFL thickness ...

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    22. Novel endoscopic diagnosis for bladder cancer

      Novel endoscopic diagnosis for bladder cancer

      A dvances in endoscopic imaging technology may improve sensitivity for the detection of bladder cancer and provide a more complete understanding of the urothelial landscape, and it also may lead to improved short-term and long-term cancer control. Fluorescence cystoscopy requires intravesical administration of a photosensitizing agent (5-aminolevulinic acid or hexaminolevulinate), and imaging with a blue-light endoscopy system demonstrably improves the detection of papillary and flat bladder lesions compared with conventional white-light cystoscopy. Prospective phase 3 clinical trials have demonstrated improved diagnostic ability, enhanced tumor resection, and a small but significant reduction in recurrence-free survival. Optical coherence tomography delineates subsurface microarchitecture ...

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