1. 721-744 of 793 « 1 2 ... 28 29 30 31 32 33 »
    1. Comparison of ex vivo optical coherence tomography with conventional frozen-section histology for visualizing basal cell carcinoma during Mohs micrographic surgery

      Comparison of ex vivo optical coherence tomography with conventional frozen-section histology for visualizing basal cell carcinoma during Mohs micrographic surgery
      Background  Mohs micrographic surgery offers high cure rates of nonmelanoma skin cancers with optimal sparing of normal tissue. However, it is generally more time-consuming and labour-intensive than traditional surgery. Optical coherence tomography (OCT) is an emergent technology that has the potential to diagnose basal cell carcinoma (BCC) in vivo.Objective  To compare the efficiency and accuracy of ex vivo OCT with frozen-section histology for identifying BCC in Mohs surgery.Methods  Thirty-eight patients were enrolled. After the stages were taken, images were captured with an OCT microscope and subsequently processed for standard frozen sections.Results  In total, 75 sections were scanned ...
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    2. A comparison of methods using optical coherence tomography to detect demineralized regions in teeth

      A comparison of methods using optical coherence tomography to detect demineralized regions in teeth
      Optical coherence tomography (OCT) is a three- dimensional optical imaging technique that can be used to identify areas of early caries formation in dental enamel. The OCT signal at 850 nm back-reflected from sound enamel is attenuated stronger than the signal back-reflected from demineralized regions. To quantify this observation, the OCT signal as a function of depth into the enamel (also known as the A-scan intensity), the histogram of the A-scan intensities and three summary parameters derived from the A-scan are defined and their diagnostic potential compared. A total of 754 OCT A-scans were analyzed. The three summary parameters derived ...
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    3. Can new optical techniques for in vivo imaging and flow cytometry of the microcirculation benefit sickle cell disease research?

      Can new optical techniques for in vivo imaging and flow cytometry of the microcirculation benefit sickle cell disease research?
      Intravital microscopy is a valuable tool for research into sickle cell disease with studies being carried out on transgenic mice and human volunteers. The method has helped to develop an explanation for sickle crises based on cell adhesion to the vascular endothelium followed by logjamming of rigid sickle cells and has stimulated much research into new treatments. In recent years there have been numerous new optical techniques developed for imaging the microcirculation and understanding the circulation of cells within the body, many of which have been further developed into in vivo flow cytometry techniques. This brief review highlights some of ...
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    4. Ability to determine postoperative status of macular hole in gas-filled eyes by spectral domain-optical coherence tomography

      Ability to determine postoperative status of macular hole in gas-filled eyes by spectral domain-optical coherence tomography
      Background:  To determine whether the status of a macular hole can be determined by spectral-domain optical coherence tomography in gas-filled eyes. Design:  Prospective study, university hospital setting. Participants:  Twenty-six eyes with a macular hole, seven eyes with a macular hole retinal detachment and four eyes with a macular hole and myopic traction maculopathy underwent vitreous surgery. Methods:  The macular area was examined by spectral-domain optical coherence tomography (OCT-4000) on postoperative days 1, 3, 7 and 30. Main Outcome Measures:  Detection of macular hole closure. Results:  The status of macular hole was able to be assessed in 24 eyes (92%) on ...
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    5. Incomplete arterial healing 8 years after the implantation of sirolimus-eluting stent. In vivo visualization by optical coherence tomography

      Incomplete arterial healing 8 years after the implantation of sirolimus-eluting stent. In vivo visualization by optical coherence tomography

      The time course of complete arterial healing after drug eluting stent implantation is unknown. We present a case of incomplete endothelialization and late stent malapposition identified by optical coherence tomography 8 years after a sirolimus-eluting stent implantation, which was not related with any adverse clinical event.

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    6. Tear meniscus measurement in nasolacrimal duct obstruction patients with Fourier-domain optical coherence tomography: novel three-point capture method

      Tear meniscus measurement in nasolacrimal duct obstruction patients with Fourier-domain optical coherence tomography: novel three-point capture method

      Purpose:  Fourier-domain optical coherence tomography (FD ODT) for the evaluation of marginal tear film has not been performed in patients with watery eye or in a controlled study. We used FD OCT to evaluate the height of the lower lid tear film at three points in normal adults and compared it with two watery eye groups.Methods:  We prospectively evaluated with FD OCT 25 normal subjects and 44 patients with a watery eye. Twenty-three patients with primary acquired nasolacrimal duct obstruction (PANDO) and 21 patients with functional nasolacrimal duct obstruction (FNLDO) were enrolled. Three images were obtained by three vertical ...

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    7. Cutting Edge Technologies in Respiratory Research: lung function testing

      Cutting Edge Technologies in Respiratory Research: lung function testing
      Pulmonary function testing is part of routine clinical practice in respiratory medicine. It is based around spirometry, which will remain the central measurement of lung function given its prognostic significance and its integral role in defining severity of airways disease. However, there is an increasing body of evidence from studies using new methods of lung function measurement which are providing new insights into pathophysiology of disease. This body of data is forming a basis for their future clinical role, once the economics of producing the relevant devices becomes attractive. The forced oscillation technique and multiple breath nitrogen washout are currently ...
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    8. Catheters for optical coherence tomography

      Catheters for optical coherence tomography
      The objective of this review article is to overview technology, clinical evidence, and future applications to date optical coherence tomography (OCT) probes to yield the diagnostic purpose. We have reviewed the designing, construction and working of different categories of OCT probes developed for optical diagnostics having a potential for non invasive and improved detection of different types of cancer as well as other neoplasm. Rotational and balloon catheters, imaging needles and hand-held, linear scanning, multichannel, micro electro mechanical systems (MEMS) technology based, dynamic focusing, forward view imaging, and common path interferometer based probes have been discussed in details. The fiber ...
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    9. Prevalence of optical coherence tomography-diagnosed post-operative cystoid macular oedema in patients following uncomplicated phacoemulsification cataract surgery

      Prevalence of optical coherence tomography-diagnosed post-operative cystoid macular oedema in patients following uncomplicated phacoemulsification cataract surgery

      Background:  Post-operative cystoid macular oedema (CMO) is a complication of uneventful cataract surgery. While improved surgical techniques have decreased the incidence of CMO, it remains a cause of unfavourable visual outcome following surgery. Fundus fluorescein angiography has been the ‘gold standard’ for diagnosing sub-clinical CMO, however non-invasive cross-sectional imaging of the retina with optical coherence tomography (OCT) may be equally effective at detecting the condition and offers the ability to quantify and repeat results over time.Design:  Prospective pre-post case series of patients undergoing routine phacoemulsification surgery.Participants:  Eighty consecutive patients (100 eyes) with cataracts and an age range of ...

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    10. Evaluation of the atrophogenic potential of hydrocortisone 1% cream and pimecrolimus 1% cream in uninvolved forehead skin of patients with atopic dermatitis using optical coherence tomography

      Evaluation of the atrophogenic potential of hydrocortisone 1% cream and pimecrolimus 1% cream in uninvolved forehead skin of patients with atopic dermatitis using optical coherence tomography
      Topical corticosteroids are widely used to treat atopic dermatitis (AD), but their anti-inflammatory mode of action can be accompanied by several unwanted side effects including skin atrophy and telangiectasia. In this 8-week, investigator-blinded, intraindividual right-left comparison study with patients with mild-to-moderate AD, hydrocortisone 1% cream (HCT) was applied twice daily for 4 weeks on one side of forehead skin without clinical signs of AD and pimecrolimus 1% cream (PIM) on the other. Epidermal and dermal thickness were assessed by optical coherence tomography (OCT) and high frequency ultrasound respectively. Skin atrophy and telangiectasia were assessed by contact dermatoscopic photography (Dermaphot®). Treatment ...
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    11. Very late thrombosis in a bare metal stent - Mechanistic analysis from optical coherence tomography

      Very late thrombosis in a bare metal stent - Mechanistic analysis from optical coherence tomography
      Recent publications have emphasized the concept that restenosis of a bare metal stent (BMS) is not as clinically benign as previously believed. We present a case of very late stent thrombosis 9 years after implantation of a BMS is described. Optical coherence tomography shows plaque rupture in the stent. These findings suggest that the formation and progression of a neoatheroma over a previously healed intrastent vascular intima may represent a “new” mechanism for stent thrombosis. Evidence from the current case supports this hypothesis.
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    12. Treatment of a Giant Coronary Artery Aneurysm: Intravascular Ultrasound and Optical Coherence Tomography Findings

      Treatment of a Giant Coronary Artery Aneurysm: Intravascular Ultrasound and Optical Coherence Tomography Findings

      A giant coronary aneurysm (GCA) partially thrombosed was demonstrated in a 77-year-old patient evaluated for an inferior myocardial infarction. Primary angioplasty (balloon only) with suboptimal result was initially obtained. After triple antiplatelet and anticoagulation therapy (4 days), a new angiography was performed and a fusiform GCA was clearly delineated. A second percutaneous intervention was performed using a “scaffolding technique” with conventional stent and subsequent implantation of 2 polytetrafluoroethylene-covered stents to successfully exclude the aneurysm. This case demonstrates a novel technique to treat long GCA

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    13. Feasibility of optical coherence tomography imaging to characterize renal neoplasms: limitations in resolution and depth of penetration

      Feasibility of optical coherence tomography imaging to characterize renal neoplasms: limitations in resolution and depth of penetration
      Study Type - Diagnostic (exploratory cohort) Level of Evidence 2b What's known on the subject? and What does the study add? Optical coherence tomography has been used for the diagnosis of retinal disease and has been used experimentally for imaging of vascular plaques, gastrointestinal pathology, bladder cancer, prostate cancer, and recently to examine benign kidney microanatomy. It has not been previously used to image kidney cancer. This study presents the first data on the utility of OCT in the imaging for renal neoplasms. It found that OCT was most successful in distinguishing AML and TCC from normal parenchyma. OCT had ...
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    14. How histological features of basal cell carcinomas influence image quality in optical coherence tomography

      How histological features of basal cell carcinomas influence image quality in optical coherence tomography
      Optical coherence tomography (OCT) has the potential to diagnose and measure the depth of nonmelanoma skin cancer (NMSC) in skin, but some lesions appear blurred in OCT images. The aim of this study is to identify histological characteristics of basal cell carcinomas (BCC) that correlate with good quality OCT images of the same lesions. A total of 34 patients with BCC were OCT scanned. The influence of histology parameters (e.g. inflammation, sun damage of skin, carcinoma cell size) on OCT image quality was studied by comparing 15 BCC lesions easily identified compared to 19 BCC lesions that produced only ...
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    15. Strategies for Assessing the Degree of Photodamage to Skin: A Systematic Review of the Literature

      Strategies for Assessing the Degree of Photodamage to Skin: A Systematic Review of the Literature
      As our understanding of the role of ultraviolet (UV) radiation exposure in causing skin cancer continues to be enhanced, it is important that clinicians and researchers are familiar with the various methods for assessing photodamage to skin. This paper provides a systematic review of the published literature on invasive and non-invasive methods used to quantify lifetime UV exposure (‘photoageing’). Clinical examination, histopathology, immunohistochemistry, skin surface topography and ultrasound, in addition to newer technologies such as reflectance confocal microscopy (RCM), optical coherence tomography (OCT) and multiphoton tomography (MPT), were reviewed. It is concluded that histopathological solar elastosis alone should not be ...
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    16. Multifocal electroretinogram and optical coherent tomography: prediction of visual outcome after epiretinal membrane removal

      Multifocal electroretinogram and optical coherent tomography: prediction of visual outcome after epiretinal membrane removal
      Purpose:  The aim was to evaluate the value of multifocal electroretinogram (mfERG) and optical coherence tomography (OCT) in predicting post-operative visual acuity (post-VA) after removal of an idiopathic epiretinal membrane (ERM). Methods:  Fifty-one eyes of 51 patients with an idiopathic macular ERM were examined by OCT and mfERG before three-port pars plana vitrectomy with removal of the ERM. The parameters of the OCT images and mfERGs, pre-operative visual acuity (pre-VA) and the duration of symptoms (DS) were compared with the post-VA. Results:  The pre-VA (r = 0.570, p < 0.001) and the duration of the symptoms (r = 0.389, p < 0.035; n = 35) were significantly correlated with the post-VA. The central retinal thickness (CRT) was significantly correlated with the pre-VA (r = 0.379, p < 0.01) and the post-VA (r = 0.318, p < 0.03). The amplitudes of macular electroretinogram (amERGs) were not significantly correlated with the pre-VA or post-VA. The CRT to amERG ratio (CRT/amERG) was correlated with the post-VA (r = 0.429, p < 0.002) but not with the pre-VA (p > 0.1). Comparative analyses among groups of cases based on CRT/amERG ...
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    17. Observations of cardiac beating behaviors of wild-type and mutant Drosophilae with optical coherence tomography

      Observations of cardiac beating behaviors of wild-type and mutant Drosophilae with optical coherence tomography
      Time-resolved optical coherence tomography (OCT) scanning images of wild-type and mutant fruit flies (Drosophila melanogaster), illustrating the heartbeat patterns for evaluating their cardiac functions, are demonstrated. Based on the heartbeat patterns, the beat rate and the relative phase between the first two heart segments can be evaluated. The OCT scanning results of mutant flies with impaired proteasome function in cardiac muscles show irregular heartbeat patterns and systematically decreased average beat rates, when compared with the regular patterns of ∼4.97 beats/s in average beat rate of the wild-type. In both wild-type and proteasome mutant flies, the beatings at different ...
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    18. A novel noncontact method to assess the biomechanical properties of wound tissue

      A novel noncontact method to assess the biomechanical properties of wound tissue
      A novel noncontact optical coherence tomography based air-jet indentation system was developed for characterizing the biomechanical properties of soft tissue in a noncontact way. This study aimed to measure the stiffness of diabetic foot ulcer tissues by using this air-jet indentation system, and examining the test/retest reliability. Eight subjects with diabetes (seven males, one female), with a total of 10 foot ulcers between them, participated in the study. A total of 20 measuring sites located at the central wound bed (n=10) or peri-ulcer areas (n=10), respectively, were evaluated with the air-jet indentation system. Four cycles of loading ...
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    19. Correlation between scanning laser polarimetry with and without enhanced corneal compensation and high-definition optical coherence tomography in normal and glaucomatous eyes

      Correlation between scanning laser polarimetry with and without enhanced corneal compensation and high-definition optical coherence tomography in normal and glaucomatous eyes
      Purpose:  To assess the relationship between high-definition optical coherence tomography (HD-OCT) and scanning laser polarimetry (SLP) with variable (VCC) and enhanced (ECC) corneal compensation in measuring peripapillary retinal nerve fibre layer (RNFL) thickness in healthy eyes and those with early-to-moderate glaucomatous VF loss. Methods:  Healthy volunteers and patients with glaucoma who met the eligibility criteria were enrolled in this prospective, cross-sectional, and observational study. Subjects underwent complete ophthalmologic examination, automated perimetry, SLP-ECC, SLP-VCC and HD-OCT. SLP parameters were recalculated in 90 degrees segments (quadrants) in the calculation circle to be compared. Pearson correlation coefficients and Lin’s concordance correlation coefficients ...
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    20. Optical coherence tomography and multifocal electroretinogram study in human immunodeficiency virus-positive children without infectious retinitis

      Optical coherence tomography and multifocal electroretinogram study in human immunodeficiency virus-positive children without infectious retinitis
      Background:  The aim was to evaluate the macular structure and function in children with human immunodeficiency virus (HIV) disease without cytomegalovirus retinitis or visual symptoms.Methods:  Thirty-eight eyes of 19 HIV-positive children (Group A) were examined. Group B included 20 (40 eyes) age- and sex-matched control subjects. Each individual underwent a complete ophthalmic examination, optical coherence tomography (OCT) scan and multifocal electroretinogram (mfERG) recording.Results:  In all patients, visual acuity and colour vision testing were normal. The mean foveal thickness in groups A and B was 190.28 ± 26.58 (SD) µm and 169.47 ± 10.17 µm, respectively (p ...
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    21. Agreement and reproducibility of gray-scale intravascular ultrasound and optical coherence tomography for the analysis of the bioresorbable vascular scaffold

      Agreement and reproducibility of gray-scale intravascular ultrasound and optical coherence tomography for the analysis of the bioresorbable vascular scaffold

      Objective:To report the agreement between grey-scale intravascular ultrasound (GS-IVUS) and optical coherence tomography (OCT) in assessing the bioresorbable vascular scaffolds (BVS) structures and their respective reproducibility.Background:BVS are composed of an erodible polymer. Ultrasound and light signals backscattered from polymeric material differs from metallic stents using GS-IVUS and OCT.Methods:Forty-five patients included in the ABSORB trial were treated with a 3.0x18 mm BVS and imaged with GS-IVUS 20 MHz and OCT post-implantation. Qualitative (ISA, side-branch struts, protrusion and dissections) and quantitative (number of struts, lumen and scaffold area) measurements were assessed by two investigators. The agreement ...

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    22. Spectral domain optical coherence tomography (SD-OCT) assessment of the healthy female canine retina and optic nerve

      Spectral domain optical coherence tomography (SD-OCT) assessment of the healthy female canine retina and optic nerve
      Objective  To provide normative data for canine whole retinal thickness (WRT), nerve fiber layer thickness (NFL), photoreceptor layer thickness (PR), and outer nuclear layer thickness (ONL) using spectral domain optical coherence tomography. Animal studied: Twelve healthy adult intact female beagles. Procedure  Horizontal volume scans through the area dorso-temporal from the optic nerve (superior retina), and the area ventro-temporal from the optic nerve (inferior retina) were used to evaluate the thickness of retinal NFL, PR, ONL, and WRT. Peripapillary circular scans were used to evaluate NFL thickness. Statistical analyses were performed to compare the thickness of the individual layers between the ...
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