1. All Articles

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    1. Role of Intravascular Imaging in Primary PCI (Book Chapter)

      Role of Intravascular Imaging in Primary PCI (Book Chapter)

      Primary percutaneous coronary intervention (PPCI) is always targeted on the angiographically identified culprit lesion. However, the actual culprit lesion may not compromise the lumen and can be located proximally or distally to the angiographic target lesion. As a result, the risk of incomplete lesion coverage can be high when the PPCI is guided solely by angiography. Furthermore, stent implantation must be optimized, as incomplete apposition and/or edge dissection may result in in-stent restenosis or acute thrombotic events. Thus, invasive coronary imaging using intravascular ultrasound or optical coherence tomography can be useful to guide the PPCI procedure by locating the ...

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    2. Clinical and OCT Findings in a Case of a Presumed Perfluorooctane Retinal Acute Toxicity

      Clinical and OCT Findings in a Case of a Presumed Perfluorooctane Retinal Acute Toxicity

      Retinal acute toxicity may be produced by several etiologies. Iatrogenic toxicity is one of the most-feared complications related to vitreoretinal surgery. The authors report a case of retinal acute toxicity due to the use of perfluorooctane during an uneventful retinal detachment surgery done elsewhere. The aim of this report is to describe the clinical and optical coherence tomography features of this complication, which unfortunately occurred in more than 100 cases in Spain.

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    3. Semi-manual Vessel Density Analysis on Optical Coherence Tomography Angiography Images of Healthy Adults

      Semi-manual Vessel Density Analysis on Optical Coherence Tomography Angiography Images of Healthy Adults

      Optical coherence tomography angiography (OCTA) is a software upgrade on conventional spectral-domain or swept-source optical coherence tomography devices that enables non-invasive, dye-free, three dimensional analysis of the retinal vessels. Vessel density is a very important parameter almost in all retinal disorders. In the recent past, automated quantification software was built into some OCTA devices which can automatically calculate the retinal vessel density as well. In this study two semi-manual techniques are used in order to analyze the vessel density of healthy subjects' OCTA images. Vessel density is also measured with a new automated quantification program, and results of the three ...

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    4. OCT vs. Angiography to Guide PCI

      OCT vs. Angiography to Guide PCI

      Study Questions: What is the effect on long-term survival of using optical coherence tomography (OCT) during percutaneous coronary intervention (PCI)? Methods: The investigators conducted a cohort study based on the Pan-London (United Kingdom) PCI registry, which includes 123,764 patients who underwent PCI in National Health Service hospitals in London between 2005 and 2015. Patients undergoing primary PCI or pressure wire use were excluded, leaving 87,166 patients in the study. The primary endpoint was all-cause mortality at a median of 4.8 years. Cox regression analysis was used to estimate hazard ratios (HRs) in the entire population and fully ...

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    5. Thorlabs Extends OCT Offering to Include 248 kHz A-Scan Rate Systems

      Thorlabs Extends OCT Offering to Include 248 kHz A-Scan Rate Systems

      Thorlabs announced today that it has expanded its well-established Ganymede™ OCT line to include two complete imaging systems offering an industry-leading A-scan rate of 248 kHz. With this new release, the GAN610C1 and GAN620C1 become the fastest commercially available Spectral-Domain OCT systems on the market, providing a new standard for high-speed, high-sensitivity 2D and 3D imaging of moving samples with reduced motion artifacts. As with Thorlabs’ previously released Ganymede™ and Telesto™ OCT systems, these new OCT systems are available in both general-purpose (GAN610) and high-resolution (GAN620 – 3 µm axial resolution) variants, each of which offers the same low roll-off and ...

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    6. Foveal avascular zone and vessel density in healthy subjects: An optical coherence tomography angiography study

      Foveal avascular zone and vessel density in healthy subjects: An optical coherence tomography angiography study

      Purpose: To report the normal characteristics and correlations of the foveal microvascular networks using optical coherence tomography angiography (OCTA) in a healthy Iranian population. Methods: Enface 3x3 OCTA images were obtained using the RTVue Avanti spectral-domain optical coherence tomography with AngioVue software (Optovue, Fremont, CA, USA). Foveal avascular zone (FAZ) area, central foveal point thickness and inner retinal thickness at the foveal center and the vascular density of the superficial retinal capillary plexus (SCP) and deep retinal capillary plexus (DCP) in the fovea were recorded. Results: Seventy normal eyes of 70 subjects (range, 9 to 71 years) were studied. Mean ...

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    7. Non-Invasive and Non-Destructive Determination of Corneal and Scleral Biomechanics Using Vibrational Optical Coherence Tomography: Preliminary Observations

      Non-Invasive and Non-Destructive Determination of Corneal and Scleral Biomechanics Using Vibrational Optical Coherence Tomography: Preliminary Observations

      Experimental measurements made in this study on human and porcine eyes suggest that the resonant frequency for both cornea and sclera varies from 130 to 150 Hz and increases slightly with increasing intraocular pressure. The values of the moduli calculated using the experimental values of the thickness are close to 2 MPa. Similar values of the modulus for cornea and sclera suggest that there is very little stress concentration at the cornea-scleral junction and that any stress concentration that occurs probably resides at the scleral attachment laterally and posteriorly. These moduli are close to those measured in vivo on human ...

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    8. Optical coherence tomography angiography in eyes with retinal vein occlusion

      Optical coherence tomography angiography in eyes with retinal vein occlusion

      Optical coherence angiography (OCTA) is a noninvasive technique that has been introduced in recent years to detect ophthalmological pathology. The growing usage of OCTA to detect retinal abnormalities can be attributed to its advantages over the reference-standard fluorescein angiography (FA), although both of these techniques can be used in association. OCTA's advantages include its dye independency, its ability to produce depth-resolved images of retinal and choroidal vessels that yield images of different vascular layers of the retina, and the better delineation of the foveal avascular zone. OCTA's disadvantages include the lack of normalized patient data, artefactual projection issues ...

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      Mentions: Cleveland Clinic
    9. Assessment of the effect of age on macular layer thickness in a healthy Chinese cohort using spectral-domain optical coherence tomography

      Assessment of the effect of age on macular layer thickness in a healthy Chinese cohort using spectral-domain optical coherence tomography

      Background To determine the effect of age on the thickness of individual retinal and choroidal vascular layers in the macula in an ophthalmologically healthy Chinese cohort by using spectral-domain optical coherence tomography (SD-OCT). Methods In all, 525 health eyes of 525 subjects were examined with SD-OCT. The instrument automatically obtained the regional retinal thickness of 8 layers. Subfoveal choroidal vascular layers’ thickness was measured using enhanced depth imaging mode. The correlation of age with layer thickness measurements was determined. Results No age-associated variation was found on retinal thickness (RT) in the fovea; however, the foveal thickness of outer nuclear layer ...

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    10. The Role of Optical Coherence Tomography in Differentiating Optic Disc Drusen from Optic Disc Edema

      The Role of Optical Coherence Tomography in Differentiating Optic Disc Drusen from Optic Disc Edema

      An elevated optic nerve head can be an ominous sign, sometimes signifying an underlying basis for raised intracranial pressure. Alternatively, patients may harbor a different mechanism for this optic nerve head appearance, including optic disc drusen (ODD), which does not confer any life-threatening implications. It is important to refine the approach to distinguishing ODD from papilledema because this is a relatively common, and important, conundrum encountered in clinical practice. Optical coherence tomography (OCT) is a noninvasive, readily accessible, and cost-effective ocular imaging technique that can improve the diagnostic accuracy for detecting ODD; or, instead, increase the index of suspicion for ...

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    11. Evaluation of peripapillary choroidal distribution in children by enhanced depth imaging optical coherence tomography

      Evaluation of peripapillary choroidal distribution in children by enhanced depth imaging optical coherence tomography

      Background To evaluate the peripapillary choroidal thickness (PPCT) in Chinese children aged 6 to 12 years old and to analyze correlative factors. Methods PPCT was measured with enhanced depth imaging optical coherence tomography (EDI-OCT) in 154 children (76 myopes and 78 emmetropia) aged 6 to 12 years, with spherical equivalent refractive errors between + 0.50 and − 5.50 diopters(D). Peripapillary choroidal imaging was performed using circular scans of a diameter of 3.4 mm around the optic disc. PPCT and the corresponding peripapillary retinal thickness (PPRT) were measured by EDI-OCT at nine positions: I, inferior; IN, inferonasal; IT, inferotemporal ...

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    12. Ganglion cell-inner plexiform layer thickness by swept-source optical coherence tomography in healthy Korean children: Normative data and biometric correlations

      Ganglion cell-inner plexiform layer thickness by swept-source optical coherence tomography in healthy Korean children: Normative data and biometric correlations

      The purpose of this study was to identify the normative values of ganglion cell-inner plexiform layer (GCIPL) thickness in healthy Korean children using swept-source optical coherence tomography (SS-OCT) and to investigate the correlations of age, refractive error, axial length (AL), retinal nerve fiber layer (RNFL) thickness and cup-to-disc (C/D) ratio with GCIPL thickness. Children aged between 3 and 17 who had visited our pediatric ophthalmology clinic were enrolled. Each subject underwent full ophthalmic examinations including RNFL thickness, C/D ratio and GCIPL thickness measurement by SS-OCT as well as AL measurement by partial-coherence interferometry. A total of 254 eyes ...

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    13. Wide field of view optical coherence tomography for structural and functional diagnoses in dentistry

      Wide field of view optical coherence tomography for structural and functional diagnoses in dentistry

      We report herein the fabrication and performance response of a three-dimensional (3-D) intraoral scan probe based on optical coherence tomography (OCT) that enables 3-D structural and functional diagnoses of the human teeth. The OCT system was configured using a swept-source OCT (SS-OCT) with a center wavelength of 1310 nm. The scan probe was built using an MEMS mirror and an optical collimator. The implemented SS-OCT equipped with the MEMS-based scan probe yielded an axial resolution of 10  μm and a scan range of 8  ×  8  mm 2 . Two-dimensional (2-D) cross-sectional images of the teeth were acquired by the scan probe ...

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      Mentions: Jonghyun Eom
    14. Comparison of cross sectional optical coherence tomography images of elevated optic nerve heads across acquisition devices and scan protocols

      Comparison of cross sectional optical coherence tomography images of elevated optic nerve heads across acquisition devices and scan protocols

      Background Optic nerve head measurements extracted from optical coherence tomography (OCT) show promise for monitoring clinical conditions with elevated optic nerve heads. The aim of this study is to compare reliability within and between raters and between image acquisition devices of optic nerve measurements derived from OCT scans in eyes with varying degrees of optic nerve elevation. Methods Wide angle line scans and narrow angle radial scans through optic nerve heads were obtained using three spectral domain(SD) OCT devices on 5 subjects (6 swollen optic nerves, 4 normal optic nerves). Three raters independently semi-manually segmented the internal limiting membrane ...

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    15. Retinal and optic nerve changes in microcephaly: An optical coherence tomography study

      Retinal and optic nerve changes in microcephaly:  An optical coherence tomography study

      Objective To investigate the morphology of the retina and optic nerve (ON) in microcephaly. Methods This was a prospective case-control study including 27 patients with microcephaly and 27 healthy controls. All participants underwent ophthalmologic examination and handheld optical coherence tomography (OCT) of the macula and ON head. The thickness of individual retinal layers was quantified at the foveal center and the parafovea (1,000 μm nasal and temporal to the fovea). For the ON head, disc diameter, cup diameter, cup-to-disc ratio, cup depth, horizontal rim diameter, rim area, peripapillary retinal thickness, and retinal nerve fiber layer thickness were measured. Results ...

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    16. Intelligent epidural needle placement using fiber-probe optical coherence tomography in a piglet model

      Intelligent epidural needle placement using fiber-probe optical coherence tomography in a piglet model

      Incorrect needle placement during an epidural block causes medical complications such as dural puncture or spinal cord injury. We propose a system combining an optical coherence tomography imaging probe with an automatic identification algorithm to objectively identify the epidural needle-tip position and thus reduce complications during epidural needle insertion. Eight quantitative features were extracted from each two-dimensional optical coherence tomography image during insertion of the needle tip from the skin surface to the epidural space. 847 in vivo optical coherence tomography images were obtained from three anesthetized piglets. The area under the receiver operating characteristic curve was used to quantify ...

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    17. Parafoveal Nonperfusion Analysis in Diabetic Retinopathy Using Optical Coherence Tomography Angiography

      Parafoveal Nonperfusion Analysis in Diabetic Retinopathy Using Optical Coherence Tomography Angiography

      Purpose : To describe a new technique for mapping parafoveal intercapillary areas (PICAs) using optical coherence tomography angiography (OCTA), and demonstrate its utility for quantifying parafoveal nonperfusion in diabetic retinopathy (DR). Methods : Nineteen controls, 15 diabetics with no retinopathy (noDR), 15 with nonproliferative diabetic retinopathy (NPDR), and 15 with proliferative diabetic retinopathy (PDR) were imaged with 10 macular OCTA scans. PICAs were automatically delineated on the averaged superficial OCTA images. Following creation of an eccentricity-specific reference database from the controls, all PICAs greater than 2 SD above the reference means for PICA area and minor axis length were identified as nonperfused ...

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    18. Optical coherence tomography angiography in intermediate uveitis

      Optical coherence tomography angiography in intermediate uveitis

      Purpose To investigate the involvement of the retinal and choriocapillaris microvasculature in intermediate uveitis on optical coherence tomography angiography (OCT-A) Design Case-control study Methods Patients and age-matched controls were imaged with swept-source OCT-A (PLEX Elite 9000, Zeiss). Using ImageJ superficial and deep retinal vasculature were semi-automatically analyzed for vessel (VD) and skeleton density (SD), vessel diameter index (VDI) and fractal dimension (FD). Choriocapillaris layer was automatically graded for mean signal intensity, signal intensity standard deviation, kurtosis of signal intensity distribution and flow-signal-voids. Results Twentynine intermediate uveitis eyes and 30 control eyes were included. Both superficial and deep retinal layers showed ...

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    19. Optical coherence tomography guided successful fibrinolytic treatment without the need for percutaneous coronary intervention in a patient with acute ST-segment elevation myocardial infarction

      Optical coherence tomography guided successful fibrinolytic treatment without the need for percutaneous coronary intervention in a patient with acute ST-segment elevation myocardial infarction

      A 36-year-old woman was admitted to the coronary care unit with a diagnosis of myocardial infarction with ST-segment elevation (STEMI) after an hour of chest pain. She was a smoker and she had no history of any other atherosclerotic risk factors. She had a stable haemodynamic status without signs of heart failure. An electrocardiogram was obtained, revealing ST-segment elevation in anterior leads and reciprocal changes in inferior leads. Given the ST-segment elevation in the context of new-onset chest pain, she was given 7500 IU of unfractionated heparin, 300 mg of aspirin, and 600 mg of clopidogrel and taken immediately for ...

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    20. Automated Layer Segmentation of Retinal Optical Coherence Tomography Images Using a Deep Feature Enhanced Structured Random Forests Classifier

      Automated Layer Segmentation of Retinal Optical Coherence Tomography Images Using a Deep Feature Enhanced Structured Random Forests Classifier

      Optical coherence tomography (OCT) is a high-resolution and non-invasive imaging modality that has become one of the most prevalent techniques for ophthalmic diagnosis. Retinal layer segmentation is very crucial for doctors to diagnose and study retinal diseases. However, manual segmentation is often a time-consuming and subjective process. In this work, we propose a new method for automatically segmenting retinal OCT images, which integrates deep features and hand-designed features to train a structured random forests classifier. The deep convolutional features are learned from deep residual network. With the trained classifier, we can get the contour probability graph of each layer, finally ...

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    21. Multi-channel optical coherence tomography probe for use in a medical procedure

      Multi-channel optical coherence tomography probe for use in a medical procedure

      A multi-channel optical coherence tomography probe for use in a medical procedure is provided. The probe comprises: a plurality of first optical fibers optically connectable to an OCT light source; a plurality of second optical fibers different from the plurality of first optical fibers; a scanning device comprising: an actuator configured to rotationally move the plurality of second optical fibers between a first position and a second position, relative to the plurality of first optical fibers; and, a mirror configured to, as the plurality of second optical fibers is moving rotationally, convey light from exit faces of the plurality of ...

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    22. Forward scanning-optical probes, circular scan patterns, offset fibers

      Forward scanning-optical probes, circular scan patterns, offset fibers

      An optical light scanning probe is presented, the probe comprising a handle, shaped for grasping by a user; a cannula, protruding from a distal portion of the handle with an outer diameter smaller than 20 gauge; an optical fiber with a distal fiber-portion off a probe-axis, configured to receive a light from a light-source at a proximal fiber-portion, and to emit the received light at the distal fiber-portion; a fixed beam forming unit, disposed at a distal portion of the cannula, configured to receive the light from the distal fiber-portion, and to deflect the received light toward a target region ...

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    23. Macular choroidal thickness in pregnant women with type 1, type 2 and gestational diabetes mellitus measured by spectral-domain optical coherence tomography

      Macular choroidal thickness in pregnant women with type 1, type 2 and gestational diabetes mellitus measured by spectral-domain optical coherence tomography

      Purpose: To analyze choroidal thickness (CT) of pregnant women with type 1 diabetes mellitus (DM), type 2 DM and gestational diabetes mellitus (GDM) using spectral-domain optical coherence tomography. Patients and methods: This cross-sectional study included 144 eyes of 72 pregnant women in the third trimester divided into four groups: 27 non-diabetic pregnant women; 15 pregnant women with GDM; 16 with type 2 DM and 14 with type 1 DM. CT was measured using optical coherence tomography at ten different locations. We also analyzed possible confounding factors, such as gestational age, glycosylated hemoglobin, time from DM diagnosis, hypertension and severity of ...

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    24. Relation of coronary culprit lesion morphology determined by optical coherence tomography and cardiac outcomes to preinfarction angina in patients with acute myocardial infarction

      Relation of coronary culprit lesion morphology determined by optical coherence tomography and cardiac outcomes to preinfarction angina in patients with acute myocardial infarction

      Background While preinfarction angina pectoris (pre-IA) is recognized as favorable effects on acute myocardial infarction (AMI), the detail has not been fully investigated. The aims of the current study were to clarify patient characteristics, lesion morphologies determined by optical coherence tomography (OCT), and cardiac outcomes related to pre-IA in patients with AMI. Methods Clinical data and outcomes were compared between AMI patients with pre-IA (pre-IA group, n = 507) and without pre-IA (non-pre-IA group, n = 653). Angiography and OCT findings were analyzed in patients with pre-intervention OCT and compared between groups of pre-IA ( n = 219) and non-pre-IA ( n = 269). Results ST-segment ...

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      Mentions: Masamichi Takano
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