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    1. Histopathological validation of optical coherence tomography findings of the coronary arteries

      Histopathological validation of optical coherence tomography findings of the coronary arteries

      Optical coherence tomography (OCT), a catheter-based imaging modality for the visualization of coronary arteries, is widely used during percutaneous coronary intervention to improve the understanding of the anatomy of coronary artery stenosis and to elucidate the mechanisms of atherosclerosis. In this review, we provide a short description of the histopathological validations of OCT for visualizing atherosclerotic plaques and vascular healing response after drug-eluting stent (DES) implantation. Because OCT measures the intensity of light returning from within a tissue, tissue having a higher heterogeneity of optical index of refraction, such as microcalcification deposition and foam cell accumulation on the luminal surface ...

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      Mentions: Kenichi Fujii
    2. Tissue-Specific Optical Mapping Models of Swine Atria Informed by Optical Coherence Tomography

      Tissue-Specific Optical Mapping Models of Swine Atria Informed by Optical Coherence Tomography

      Computational models and experimental optical mapping of cardiac electrophysiology serve as powerful tools to investigate the underlying mechanisms of arrhythmias . Modeling can also aid the interpretation of optical mapping signals, which may have different characteristics with respect to the underlying electrophysiological signals they represent. However, despite the prevalence of atrial arrhythmias such as atrial fibrillation , models of optical electrical mapping incorporating realistic structure of the atria are lacking. Therefore, we developed image-based models of atrial tissue using structural information extracted from optical coherence tomography (OCT), which can provide volumetric tissue characteristics in high resolution. OCT volumetric data of four swine ...

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    3. Detection of Latent Fingerprint Hidden Beneath Adhesive Tape by Optical Coherence Tomography

      Detection of Latent Fingerprint Hidden Beneath Adhesive Tape by Optical Coherence Tomography

      Adhesive tape is one type of common item which can be encountered in criminal cases involving rape, murder, kidnapping and explosives. It is often the case that a suspect deposits latent fingerprints on the sticky side of adhesive tape material when tying up victims, manufacturing improvised explosive devices or packaging illegal goods. However, the adhesive tapes found at crime scenes are usually stuck together or attached to a certain substrate, and thus the latent fingerprints may be hidden beneath the tapes. Current methods to detect latent fingerprint hidden beneath adhesive tape need to peel it off first and then apply ...

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    4. Impact of correct anatomical slab segmentation on foveal avascular zone measurements by optical coherence tomography angiography in healthy adults

      Impact of correct anatomical slab segmentation on foveal avascular zone measurements by optical coherence tomography angiography in healthy adults

      urpose To evaluate the impact of correct anatomical slab segmentation on foveal avascular zone (FAZ) dimensions in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) using optical coherence tomography angiography (OCTA). Methods Participants with healthy retinas were recruited, and 5 × 5 mm OCTA images were acquired using the Canon HS-100 Angio eXpert module. FAZ size was measured in automatically (AS, manufacturer-based) and manually (MS, anatomical-based) segmented OCTA slabs by two experienced graders. FAZ dimensions, inter-rater agreement, and correlation to demographic and retinal parameters were evaluated. Results A total of 38 eyes from 20 healthy adult subjects were included ...

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    5. ORGANIZATION OF THROMBUS CONTRIBUTES TO RAPID PROGRESSION OF CORONARY ARTERY DISEASE: A SERIAL CORONARY ANGIOGRAMS AND OPTICAL COHERENCE TOMOGRAPHY STUDY

      ORGANIZATION OF THROMBUS CONTRIBUTES TO RAPID PROGRESSION OF CORONARY ARTERY DISEASE: A SERIAL CORONARY ANGIOGRAMS AND OPTICAL COHERENCE TOMOGRAPHY STUDY

      Background The process of progression of coronary artery disease (CAD) is generally classified as either rapid progression or continuous slight progression in daily clinical practice. However, the precise mechanism of rapid progression in CAD is unknown. Methods This study consists of 62 lesions with clinically significant progression of CAD (>10%/year) in which serial coronary angiogram and optical coherence tomography (OCT) were performed at intervals of approximately 1 year. From the angiographic progression pattern, 20 lesions (32%) were categorized as rapid progression (≥50%) and 42 lesions (68%) as slight progression. Plaque morphology was classified on the basis of OCT findings ...

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      Mentions: Kenichi Fujii
    6. Morpho-functional evaluation of torpedo maculopathy with optical coherence tomography angiography and microperimetry

      Morpho-functional evaluation of torpedo maculopathy with optical coherence tomography angiography and microperimetry

      Purpose To report the case of a 13-year-old girl with torpedo maculopathy, evaluated with multimodal morpho-functional retinal imaging, including fundus photography, infra-red and blue fundus autofluorescence, swept-source optical coherence tomography (OCT), en face OCT, OCT angiography and microperimetry (MP). Observations On fundus examination, a torpedo-like hypopigmented lesion was observed temporal to the fovea in the left eye. OCT showed disruption of outer retinal layers and the presence of a subretinal cleft. On OCTA, a diffuse attenuation of signal from choriocapillaris was observed along the lesion. Functional analysis with MP revealed a reduction of retinal sensitivity over the lesion. Conclusions and ...

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    7. Mobilization of progenitor cells and assessment of vessel healing after second generation drug-eluting stenting by optical coherence tomography

      Mobilization of progenitor cells and assessment of vessel healing after second generation drug-eluting stenting by optical coherence tomography

      Background Bone marrow-derived progenitor cells likely contribute to both endothelial- and smooth muscle cell-dependent healing responses in stent-injured vessel sites. This study aimed to assess mobilization of progenitor cells and vessel healing after zotarolimus-eluting (ZES) and everolimus-eluting (EES) stents. Methods and results In 63 patients undergoing coronary stent implantation, we measured circulating CD34 + CD133 + CD45low cells and serum levels of biomarkers relevant to stem cell mobilization . In 31 patients of them, we assessed vessel healing within the stented segment using optical coherence tomography (OCT) imaging. The CD34 + CD133 + CD45low cells increased 68 ± 59% 7 days after bare metal stent (BMS ...

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    8. Impact of Ticagrelor and Aspirin versus Clopidogrel and Aspirin in Symptomatic Patients with Peripheral Arterial Disease: Thrombus Burden Assessed by Optical Coherence Tomography

      Impact of Ticagrelor and Aspirin versus Clopidogrel and Aspirin in Symptomatic Patients with Peripheral Arterial Disease: Thrombus Burden Assessed by Optical Coherence Tomography

      Purpose To compare OCT identified white thrombus decline, neointimal hyperplasia and clinical outcomes of patients treated with ticagrelor plus aspirin with those patients treated with clopidogrel plus aspirin after peripheral interventions. Background Ticagrelor is a potent platelet inhibitor. In patients with coronary artery disease, ticagrelor and aspirin demonstrated reduced rates of stent thrombosis, compared to aspirin and clopidogrel. The clinical importance of potent antiplatelet inhibition after peripheral endovascular interventions is unknown. Methods We enrolled 18 patients with superficial femoral artery disease and the presence of OCT-detected clot post-stent placement. Patients were randomized to 75 mg clopidogrel once daily for 1 ...

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    9. Predictors of Retinal Atrophy in Multiple Sclerosis: A Longitudinal Study Using Spectral Domain Optical Coherence Tomography with Segmentation Analysis

      Predictors of Retinal Atrophy in Multiple Sclerosis: A Longitudinal Study Using Spectral Domain Optical Coherence Tomography with Segmentation Analysis

      Background Multiple sclerosis is an inflammatory demyelinating disease characterized by progressive axonal loss affecting mainly the inner retinal layers. Optical coherence tomography (OCT) provides in-vivo quantification of the retinal layers and allows measuring progressive retinal changes. Our objective was to assess the longitudinal changes in the retina using spectral domain OCT (SDOCT) and to identify independent predictors affecting retinal thinning in MS patients. Methods A prospective study in a tertiary care MS center was conducted to study the longitudinal retinal changes in MS patients. All subjects underwent baseline and follow up OCT assessment with segmentation analysis. Regression analysis was performed ...

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    10. Quantitative comparisons between optical coherence tomography angiography and matched histology in the human eye

      Quantitative comparisons between optical coherence tomography angiography and matched histology in the human eye

      The aim was to quantitatively compare retinal vascular detail as seen on optical coherence tomography angiography (OCTA) and matched histology in the human eye. 13 normal human donor eyes were used. The central retinal artery was cannulated after which human packed red blood cells were perfused through the retinal vasculature. Retinal vessels were imaged using a custom-built OCTA device during red blood cell perfusion. The eye was subsequently perfused with endothelial cell antibodies and the flat-mounted retina studied histologically using a confocal scanning laser microscope. Qualitative and quantitative comparisons of retinal vascular information as seen on OCTA and histology from ...

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    11. Blood vessel segmentation algorithms — Review of methods, datasets and evaluation metrics

      Blood vessel segmentation algorithms — Review of methods, datasets and evaluation metrics

      Background Blood vessel segmentation is a topic of high interest in medical image analysis since the analysis of vessels is crucial for diagnosis, treatment planning and execution, and evaluation of clinical outcomes in different fields, including laryngology, neurosurgery and ophthalmology. Automatic or semi-automatic vessel segmentation can support clinicians in performing these tasks. Different medical imaging techniques are currently used in clinical practice and an appropriate choice of the segmentation algorithm is mandatory to deal with the adopted imaging technique characteristics (e.g. resolution, noise and vessel contrast). Objective This paper aims at reviewing the most recent and innovative blood vessel ...

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    12. Influence of the Loci of Non-Cavitated Fissure Caries on Its Detection with Optical Coherence Tomography

      Influence of the Loci of Non-Cavitated Fissure Caries on Its Detection with Optical Coherence Tomography

      Objective The main objective of this study was to evaluate the accuracy of optical coherence tomography (OCT) in detecting naturally occurring non-cavitated fissure caries (NCFC) in totality and at different loci by visually assessing cross-sectional OCT scans (B-scan) with an interpretation criterion. The secondary objective was to evaluate the agreement between dimensions of NCFC measured with OCT and polarized light microscopy (PLM). Methods 71 investigation sites of sound fissure and naturally occurring NCFC on human extracted premolars were identified and scanned with a swept-source OCT. The teeth were then sectioned bucco-lingually at the investigation sites and imaged using PLM. Two ...

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    13. Phase Contrast Tomography at Lab on Chip scale by Digital Holography

      Phase Contrast Tomography at Lab on Chip scale by Digital Holography

      High-throughput single-cell analysis is a challenging target for implementing advanced biomedical applications. An excellent candidate for this aim is label-free tomographic phase microscopy (TPM). In this paper, some of the methods used to obtain TPM are reviewed, analyzing advantages and disadvantages of each of them. Moreover, an alternative tomographic technique is described for live cells analysis, and future trends of the method are foreseen. In particular, by exploiting random rolling of cells while they are flowing along a microfluidic channel, it is possible to obtain phase-contrast tomography thus obtaining complete retrieval of both 3D-position and orientation of rotating cells. Thus ...

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    14. Comparison of chorioretinal layers in rhesus macaques using spectral-domain optical coherence tomography and high-resolution histological sections

      Comparison of chorioretinal layers in rhesus macaques using spectral-domain optical coherence tomography and high-resolution histological sections

      Nonhuman primates are important preclinical models of retinal diseases because they uniquely possess a macula similar to humans. Ocular imaging technologies such as spectral-domain optical coherence tomography (SD-OCT) allow noninvasive, in vivo measurements of chorioretinal layers with near-histological resolution. However, the boundaries are based on differences in reflectivity, and detailed correlations with histological tissue layers have not been explored in rhesus macaques, which are widely used for biomedical research. Here, we compare the macular anatomy and thickness measurements of chorioretinal layers in rhesus macaque eyes using SD-OCT and high-resolution histological sections. Images were obtained from methylmethacrylate-embedded histological sections of 6 ...

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    15. In Vivo Automated Quantification of Thermally Damaged Human Tissue Using Polarization Sensitive Optical Coherence Tomography

      In Vivo Automated Quantification of Thermally Damaged Human Tissue Using Polarization Sensitive Optical Coherence Tomography

      Over the decades numerous technologies have been performed for the quantification of skin injuries, but their poor sensitivity, specificity and accuracy limits their applications. Optical coherence tomography (OCT) can be potential tool for the identification but the modern high-speed OCT system acquires huge amount of data, which will be very time-consuming and tedious process for human interpretation. Our proposed method opens the possibility of fully automated quantitative analysis based on morphological features of thermally damaged tissue, which will become biomarker for the removal of non-viable skin. The proposed method is based on multi-level ensemble classifier by dissociating morphological features (A-line ...

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    16. Indocyanine Green Dye Filling Time for Polypoidal Lesions in Polypoidal Choroidal Vasculopathy Affects the Visibility of the Lesions on OCT Angiography

      Indocyanine Green Dye Filling Time for Polypoidal Lesions in Polypoidal Choroidal Vasculopathy Affects the Visibility of the Lesions on OCT Angiography

      Purpose To elucidate the factors that affect the visibility of polypoidal lesions on OCT angiography (OCTA) based on indocyanine green angiography (ICGA) findings in eyes with polypoidal choroidal vasculopathy (PCV). Design Retrospective, consecutive case series. Participants Thirty-one eyes of 31 patients with PCV diagnosed on ICGA. Methods We compared the numbers of polyps visible on ICGA and on OCTA. The following time points and durations were determined: first appearance of dye in the choroidal arteries, first appearance of dye within a polyp, and the time it took the dye to fill entire lesions. Then we compared visible and invisible polyps ...

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    17. Spectral optical coherence tomography findings in an elderly patient with syphilitic bilateral chronic panuveitis

      Spectral optical coherence tomography findings in an elderly patient with syphilitic bilateral chronic panuveitis

      Purpose To report the spectral domain optical coherence tomography (SD-OCT) features of a focal retinitis in an elderly male patient with bilateral syphilitic panuveitis. Observations In the left eye (LE), spectral domain SD-OCT images during the active period revealed hyperreflectivity extending through the full thickness of the retina with no individualization of the layers, except for the retinal pigment epithelium. Once the lesion healed, SD-OCT imaging revealed an inner retinal atrophy and a mild disruption of the retinal pigment epithelium. Conclusions and importance In our patient, treponemal infection seemed to produce full-thickness retinal damage with partial involvement of the retinal ...

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    18. Optical coherence tomography angiography of a pigmented Fuchs' adenoma (age-related hyperplasia of the nonpigmented ciliary body epithelium) masquerading as a ciliary body melanoma

      Optical coherence tomography angiography of a pigmented Fuchs' adenoma (age-related hyperplasia of the nonpigmented ciliary body epithelium) masquerading as a ciliary body melanoma

      Purpose To report a case of age-related hypertrophy of the nonpigmented ciliary epithelium (ARH-NPCE) clinically resembling a ciliary body melanoma and report the optical coherence tomography angiography (OCTA) findings associated with this lesion. Observations A 51-year-old male was referred for evaluation of a deeply pigmented ciliary body mass with extension through the iris root. Iridocyclectomy was performed due to concern for ciliary body melanoma. Histopathologic analysis was instead consistent with ARH-NPCE, also known as Fuchs' adenoma. Prior to surgery, OCTA images revealed abnormal vasculature in the area of the lesion. Vessels in the peripheral iris approaching the lesion appeared more ...

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    19. An Automated Method for Choroidal Thickness Measurement from Enhanced Depth Imaging Optical Coherence Tomography Images

      An Automated Method for Choroidal Thickness Measurement from Enhanced Depth Imaging Optical Coherence Tomography Images

      The choroid is vascular tissue located underneath the retina and supplies oxygen to the outer retina; any damage to this tissue can be a precursor to retinal diseases. This paper presents an automated method of choroidal segmentation from enhanced depth imaging optical coherence tomography (EDI-OCT) images. The Dijkstra shortest path algorithm is used to segment the choroid-sclera interface (CSI), the outermost border of the choroid. A novel intensity-normalisation technique that is based on the depth of the choroid is used to equalise the intensity of all non-vessel pixels in the choroid region. The outer boundary of choroidal vessel and CSI ...

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    20. The EYE-MI study: A prospective acute coronary syndrome cohort evaluated by retinal optical coherence tomography angiography

      The EYE-MI study: A prospective acute coronary syndrome cohort evaluated by retinal optical coherence tomography angiography

      Background Retinal artery calibre correlates with the risk of cardiovascular events, and could serve as an inexpensive and reproducible biomarker for cardiovascular diseases. Recently, a non-invasive approach for retinal imaging with OCT angiography has been proposed to evaluate retinal blood vessel density. Methods The EYE-MI study prospectively included all consecutive patients admitted to our University Hospital for acute coronary syndrome (ACS) between October, 1st and December, 31st 2016. Patients with retinal diseases were excluded. Retinal OCT angiography was performed within 2 days after admission to assess inner retina vascular density (IRVD), based on blood flow. Results Of 212 patients admitted ...

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    1-24 of 803 1 2 3 4 ... 32 33 34 »
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