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    1. Relationship between vessel diameter and depth measurements within the limbus using ultra-high resolution optical coherence tomography

      Relationship between vessel diameter and depth measurements within the limbus using ultra-high resolution optical coherence tomography

      To establish a relationship between the diameter and depth position of vessels in the superior and inferior corneo-scleral limbus using ultra-high resolution optical coherence tomography (UHR-OCT). Methods Volumetric OCT images of the superior and inferior limbus were acquired from 14 healthy subjects with a research-grade UHR-OCT system. Differences in vessel diameter and depth between superior and inferior limbus were analyzed using repeated measured ANOVA in SPSS and R. Results The mean (± SD) superior and inferior diameters were 29 ± 18 μm and 24 ± 18 μm respectively, and the mean (± SD) superior and inferior depths were 177 ± 109 μm and 207 ± 132 ...

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    2. Investigating the influence of organic matter composition on biofilm volumes in reverse osmosis using optical coherence tomography

      Investigating the influence of organic matter composition on biofilm volumes in reverse osmosis using optical coherence tomography

      Biofouling, a critical issue in membrane filtration, is influenced by several factors such as membrane characteristics and feed water quality. The organic matter (OM) composition is known to significantly influence biofilm formation, but few studies on this subject have been reported. Optical coherence tomography (OCT) allows direct monitoring of biofilm development on the membrane surface without the need for membrane autopsy. The purposes of the present study are 1) to quantify biofouling formation on a membrane surface using OCT; 2) to monitor the temporal variation of OM composition during membrane formation; and 3) to investigate the variation of OM composition ...

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    3. Spectral domain optical coherence tomography findings of patients under treatment for pediatric acute lymphoblastic leukemia

      Spectral domain optical coherence tomography findings of patients under treatment for pediatric acute lymphoblastic leukemia

      Purpose To investigate the use of spectral domain optical coherence tomography (SD-OCT) findings in pediatric acute lymphoblastic leukemia (ALL) patients. Methods Children that were diagnosed with precursor B-cell ALL and classified as belonging to the medium-risk group for relapse were selected for this study. Individuals who were in continuous remission and on maintenance therapy were included in the study group. Cases that had central nervous system involvement were excluded. Age-matched, otherwise healthy children were selected for the control group. Each study participant underwent a comprehensive eye examination and SD-OCT evaluation. Thickness measurements were made within the retinal nerve fiber layer ...

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    4. Pharmaceutical film coating catalogue for spectral-domain optical coherence tomography

      Pharmaceutical film coating catalogue for spectral-domain optical coherence tomography

      Optical coherence tomography (OCT) has recently been demonstrated to measure the film coating thickness of pharmaceutical tablets and pellets directly. The results enable the analysis of inter- and intra-tablet coating variability at an off-line and in-line setting. To date, only a few coating formulations have been tried and there is very little information on the applicability of OCT to other coatings. As it is well documented that optical methods including OCT are prone to scattering leading to limited penetration, some pharmaceutical coatings may not be measurable altogether. This study presents OCT measurements of 22 different common coatings for the assessment ...

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    5. Morphological and pharmacological determinants of peri-procedural myocardial infarction following elective stent implantation: Optical coherence tomography sub-analysis of the PRASFIT-Elective study

      Morphological and pharmacological determinants of peri-procedural myocardial infarction following elective stent implantation: Optical coherence tomography sub-analysis of the PRASFIT-Elective study

      Background Previous studies have suggested that peri-procedural myocardial infarction (PMI) following percutaneous coronary intervention (PCI) is associated with adverse short- and long-term outcomes, and several morphological predictors of PMI have been studied. However, the determinants of PMI under novel anti-platelet therapy are not fully elucidated. Methods and results PRASFIT-Elective is a multicenter, parallel-group study of PCI patients in non-acute settings receiving either prasugrel or clopidogrel in addition to aspirin. Among 742 study patients, 94 (116 lesions) underwent optical coherence tomography (OCT) to evaluate the area of intra-stent tissue (IST, which comprises tissue protrusion and thrombus) after stenting in addition to ...

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    6. OCT assessment of non-cavitated occlusal carious lesions by variation of incidence angle of probe light and refractive index matching

      OCT assessment of non-cavitated occlusal carious lesions by variation of incidence angle of probe light and refractive index matching

      Objectives This study evaluated (1) the detection and assessment of non-cavitated occlusal carious lesions by spectral domain optical coherence tomography (SD-OCT) and (2) the impact of varying angle of incidence (AI) of probe light and refractive index matching (RIM). Methods Nine extracted human molars with 18 occlusal lesions (ICDAS code 2) were visually selected. 18 regions of interest (ROI) were imaged with SD-OCT under varying AI (0°, ±5°, ±10°, ±15°) and with/without application of glycerine at 0°. X-ray micro computed tomography (μCT) was used as a validation standard. μCT and OCT signals were categorized according to the lesion extent ...

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    7. Coronary artery aneurysm formation following implantation of a bioresorbable vascular scaffold for in-stent restenosis

      Coronary artery aneurysm formation following implantation of a bioresorbable vascular scaffold for in-stent restenosis

      Coronary artery aneurysm (CAA) formation is a rare complication of coronary intervention that may develop after implantation of bare-metal or drug-eluting stents. The etiology of this entity appears to be multifactorial and its prognosis is poorly understood, but it has been associated with an increased risk of stent thrombosis. To date few cases of CAAs related to bioresorbable vascular scaffold (BVS) implantation have been reported, and the development of CAA after BVS implantation for the treatment of in-stent restenosis (ISR) has not been previously described. Here we present two cases of CAA formation after BVS, which represent the first demonstration ...

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      Mentions: Fernando Alfonso
    8. An interesting case of a self-apposing stent implantation in an aneurysmatically dilated artery in acute myocardial infarction with high quality optical coherence tomography images

      An interesting case of a self-apposing stent implantation in an aneurysmatically dilated artery in acute myocardial infarction with high quality optical coherence tomography images

      56-Year-old man with non-ST-segment elevation myocardial infarction. Coronary angiography showed aneurysmatic changes of the left circumflex artery with near occlusion of this vessel. We have decided to implant a Self-Apposing® Coronary Stent Xposition S (Stentys SA, Paris, France). In optical coherence tomography a good stent apposition has been confirmed. A complete distal flow in the infarct-related artery was achieved. Implantation of DES in a large vessel, especially with aneurysmatic dilatation is limited due to difficulties in choosing a proper stent size. Undersizing may cause stent malapposition which carries an increased risk of late and very late stent thrombosis. Oversizing may ...

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      Mentions: Dariusz Dudek
    9. Clinical Significance of Lipid-Rich Plaque Detected by Optical Coherence Tomography : A 4-Year Follow-Up Study

      Clinical Significance of Lipid-Rich Plaque Detected by Optical Coherence Tomography : A 4-Year Follow-Up Study

      Background Lipid-rich plaque (LRP) is thought to be a precursor to cardiac events. However, its clinical significance in coronary arteries has never been systematically investigated. Objectives This study investigated the prevalence and clinical significance of LRP in the nonculprit region of the target vessel in patients undergoing percutaneous coronary intervention (PCI). Methods The study included 1,474 patients from 20 sites across 6 countries undergoing PCI, who had optical coherence tomography (OCT) imaging of the target vessel. Major adverse cardiac events (MACE) were defined as a composite of cardiac death, acute myocardial infarction, and ischemia-driven revascularization. Patients were followed for ...

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    10. Low molecular weight Dextran: An alternative to radiographic contrast agent for Optical coherence tomography imaging

      Low molecular weight Dextran: An alternative to radiographic contrast agent for Optical coherence tomography imaging

      Optical coherence tomography (OCT) requires a radiographic contrast agent to replace the blood during intra-vascular imaging. Increase use of contrast volume during OCT imaging may further worsen the renal functions in patients who are at high risk for contrast induced nephropathy (CIN). 1 Low molecular weight Dextran-40 can be an alternative to contrast agent during OCT imaging. 2 ; 3 Dextran-40 is a sterile, non-pyrogenic preparation of low molecular weight dextran (40,000 molecular weight- 10 gm%) in 5% Dextrose or 0.9% sodium chloride injection. We compared the image quality of Iohexol 350 mg I/ml radiographic contrast agent (GE ...

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      Mentions: GE Healthcare
    11. Analysis of Retinochoroidal Vasculature in Human Immunodeficiency Virus Infection Using Spectral-Domain OCT Angiography

      Analysis of Retinochoroidal Vasculature in Human Immunodeficiency Virus Infection Using Spectral-Domain OCT Angiography

      Purpose To describe the retinochoroidal vascular alterations in patients with human immunodeficiency virus (HIV) infection using en face OCT angiography (OCTA). Design Cross-sectional study. Participants Twenty-six patients with HIV infection (5 women, with and without HIV retinopathy) were included in the study. Nineteen healthy participants (7 women) with no known ocular disease were recruited as healthy controls. Methods Multimodal imaging was performed using OCTA (Optovue RTVue XR Avanti; Optovue, Inc, Fremont, CA), enhanced-depth imaging OCT (Heidelberg Spectralis; Heidelberg Engineering, Heidelberg, Germany), color fundus photography, and fluorescein angiography (FA). Vessel flow density (VFD) was calculated automatically by the OCTA software. Morphologic ...

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    12. Prognosis of spontaneous coronary artery dissection treated by percutaneous coronary intervention with optical coherence tomography

      Prognosis of spontaneous coronary artery dissection treated by percutaneous coronary intervention with optical coherence tomography

      Background Although about half of patients with spontaneous coronary artery dissection (SCAD) face ongoing necrosis, conservative therapy is recommended due to a high complication rate in angiography-guided percutaneous coronary intervention (PCI). The aim of this study was to investigate clinical outcomes of SCAD treated by optical coherence tomography (OCT)-guided PCI. Methods This study consisted of consecutive 306 patients with acute coronary syndrome (ACS) who underwent OCT-guided PCI. Based on the culprit lesion morphology by OCT, patients were assigned to four groups: a SCAD group, a plaque rupture (PR) group, a calcified nodule (CN) group, and an undetermined etiology (UE ...

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    13. Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography

      Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography

      Purpose To describe a method to obtain images of the choroid using conventional spectral-domain (SD) optical coherence tomography (OCT) and to evaluate choroidal thickness measurements using these images. Design Observational case series. Methods The images were obtained by positioning the SD OCT device close enough to the eye to obtain an inverted representation of the fundus in healthy volunteers who did not have pupillary dilation. Seven sections, each comprised of 100 averaged scans, were obtained within a 5- × 15-degree rectangle centered on the fovea. The choroidal thickness under the fovea in each image was measured by independent observers. Results The ...

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    14. Dual-channel phase-contrast spectral optical coherence tomography for simultaneously measuring axial and normal to B-scan off-axial displacements

      Dual-channel phase-contrast spectral optical coherence tomography for simultaneously measuring axial and normal to B-scan off-axial displacements

      A dual-channel phase-contrast spectral optical coherence tomography (DPC-SOCT) method is proposed for measuring axial and normal to B-scan off-axial displacements inside weakly scattering translucent materials. By employing a dual-channel observation structure with depth multiplexing, only one shot before and one shot after the object deformation are required for simultaneously measuring the displacements. To validate the method, a DPC-SOCT system was built and axial and normal to B-scan off-axial displacements inside polymer films were measured at 20 frames per second. The results suggest that the method can be used for investigating inner mechanical properties of materials under different loads. In the ...

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    15. Choroidal Imaging with Swept-Source Optical Coherence Tomography in Patients with Birdshot Chorioretinopathy: Choroidal Reflectivity and Thickness

      Choroidal Imaging with Swept-Source Optical Coherence Tomography in Patients with Birdshot Chorioretinopathy: Choroidal Reflectivity and Thickness

      Purpose To characterize choroidal thickness and choroidal reflectivity in the eyes of patients with birdshot chorioretinopathy (BSCR). Design Cross-sectional observational study. Participants Two hundred twenty BSCR patients and 59 healthy controls. Methods Patients with BSCR and healthy controls underwent imaging of the macula in both eyes with a swept-source optical coherence tomography device (DRI-OCT1 Atlantis; Topcon). Images were exported from the device, and analysis was performed by 2 graders in the Doheny Image Reading Center using Image J software. The choroidal thickness at the foveal center was measured. In addition, the inner and outer boundaries of the choroid and retinal ...

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      Mentions: UCLA
    16. Impact of Plaque Rupture Detected by Optical Coherence Tomography on Transmural Extent of Infarction After Successful Stenting in ST-Segment Elevation Acute Myocardial Infarction

      Impact of Plaque Rupture Detected by Optical Coherence Tomography on Transmural Extent of Infarction After Successful Stenting in ST-Segment Elevation Acute Myocardial Infarction

      bjectives The aim of the present study was to investigate the association between plaque rupture (PR) assessed by optical coherence tomography (OCT), and the transmural extent of infarction (TEI) assessed by contrast-enhanced cardiac magnetic resonance imaging (CE-CMR) in ST-segment elevation myocardial infarction (STEMI) patients after primary percutaneous coronary intervention (PCI). Background PR is associated with larger infarct size as assessed by cardiac enzymes in STEMI patients. CE-CMR is a favorable method to assess TEI, which can predict the prognosis of STEMI patients. Methods First, STEMI patients with primary PCI within 12 h after onset were enrolled and divided into 2 ...

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    17. Optical Coherence Tomography Findings in Patients with Bipolar Disorder

      Optical Coherence Tomography Findings in Patients with Bipolar Disorder

      Background Research in bipolar disorder suggests the presence of structural brain abnormalities. It is not clear whether these findings are trait markers or operate with the onset and progress with disease severity and duration. Optical coherence tomography (OCT) is a non-invasive technique that detects degenerative changes in the retina reflecting brain degeneration. This study aimed at detecting these changes and relating them to disease severity and clinical characteristics. Methods A case-control study conducted in Psychiatry and Addiction Medicine hospital, Faculty of Medicine at Cairo University. Forty inpatients with bipolar disorder -according to the 4 th edition of the Diagnostic and ...

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    18. Assessment of enamel cracks at adhesive cavosurface margin using three-dimensional swept-source optical coherence tomography

      Assessment of enamel cracks at adhesive cavosurface margin using three-dimensional swept-source optical coherence tomography

      Objectives Swept-source optical coherence tomography (SS-OCT) can construct cross-sectional images of internal biological structures. The aim of this study was to evaluate enamel cracks at the cavosurface margin of composite restorations using SS-OCT. Methods Bowl-shaped cavities were prepared at two locations (mid-coronal and cervical regions) on the enamel surface of 60 bovine teeth. Half of the cavities (30) were treated with phosphoric acid gel. A two-step self-etch adhesive (Clearfil SE Bond) was applied to all cavities and a flowable composite was placed in bulk. After 7 days in water at 37 °C, three-dimensional (3D) images of the specimens were obtained ...

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    19. Discriminating hidden bruises in loquat by attenuation coefficients estimated from optical coherence tomography images

      Discriminating hidden bruises in loquat by attenuation coefficients estimated from optical coherence tomography images

      Hidden bruising is considered as one of the difficulties during loquat quality control, which has made an impact on postharvest quality and storability. Optical coherence tomography (OCT) is used as a non-destructive method that acquires 2D images of the sub-surface structure of the loquat. After OCT image processing, the attenuation coefficients ( μ t ) of the regions of interests are fitted to quantitatively analyze the characteristics of loquat tissue through using a confocal signal scattering model from OCT A-scan signals. In this experiment, a total of 60 loquat samples are investigated, with the non-bruised tissue having a large μ t with a mean ...

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    20. Emerging Applications of Optical Coherence Tomography in Pediatric Optic Neuropathies

      Emerging Applications of Optical Coherence Tomography in Pediatric Optic Neuropathies

      Limited cooperation and attention span often lead to poorly reliable assessments of visual acuity and visual fields in children, making diagnosis and monitoring of pediatric optic neuropathies challenging. As a noninvasive imaging modality, optical coherence tomography (OCT) could offer particular utility in this patient population. OCT provides high-resolution characterization of the optic nerve head, peripapillary retinal nerve fiber layer, and cellular layers of the macula, all of which can be used to assess the severity of optic nerve disease qualitatively and quantitatively. Application of OCT to pediatric patients has been limited by technical factors and lack of pediatric normative databases ...

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      Mentions: Duke University
    21. Agreement between OCT Leakage and Fluorescein Angiography to Identify Sites of Alteration of the Blood–Retinal Barrier in Diabetes

      Agreement between OCT Leakage and Fluorescein Angiography to Identify Sites of Alteration of the Blood–Retinal Barrier in Diabetes

      Purpose To compare the location of the sites of lower reflectivity, as determined by OCT leakage using spectral domain (SD)-OCT, with sites of fluorescein leakage identified by fluorescein angiography (FA) in eyes with diabetic retinopathy. Design Prospective consecutive case series. Participants Fifty-two eyes from 28 patients with type 2 diabetes and presence of nonproliferative diabetic retinopathy. Methods All patients were imaged with FA and SD-OCT (Angioplex, Carl Zeiss Meditec, Inc). All FA images were analyzed by 2 experienced graders, and the area surrounding well-defined sites of leakage was outlined by the graders. The SD-OCT scans were processed using OCT ...

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    1-24 of 689 1 2 3 4 ... 27 28 29 »
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