All Articles from gijs van soest -Optical Coherence Tomography News

Articles from gijs van soest

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1. Intravascular optical coherence elastography
  
  Explore Optica Publishing Group Nov 27 2022 Cardiology
  
  Optical coherence elastography (OCE), a functional extension of optical coherence tomography (OCT), visualizes tissue strain to deduce the tissue's biomechanical properties. In this study, we demonstrate intravascular OCE using a 1.1 mm motorized catheter and a 1.6 MHz Fourier domain mode-locked OCT system. We induced an intraluminal pressure change by varying the infusion rate from the proximal end of the catheter. We analysed the pixel-matched phase change between two different frames to yield the radial strain. Imaging experiments were carried out in a phantom and in human coronary arteries in vitro . At an imaging speed of 3019 ...
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  Mentions: Delft University of Technology Chinese Academy of Sciences University of Lübeck
2. Intravascular Imaging-Derived Physiology—Basic Principles and Clinical Application
  
  Explore Interventional Cardiology Clinics Nov 14 2022 Cardiology
  
  Intravascular imaging-derived physiology is emerging as a promising tool allowing simultaneous anatomic and functional lesion assessment. Recently, several optical coherence tomography-based and intravascular ultrasound-based fractional flow reserve (FFR) indices have been developed that compute FFR through computational fluid dynamics, fluid dynamics equations, or machine-learning methods. This review aims to provide an overview of the currently available intravascular imaging-based physiologic indices, their diagnostic performance, and clinical application
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  Mentions: Erasmus University
3. Spectroscopic thermo-elastic optical coherence tomography for tissue characterization
  
  Explore Optica Publishing Group Feb 20 2022
  
  Optical imaging techniques that provide free space, label free imaging are powerful tools in obtaining structural and biochemical information in biological samples. To date, most of the optical imaging technologies create images with a specific contrast and require multimodality integration to add additional contrast. In this study, we demonstrate spectroscopic Thermo-elastic Optical Coherence Tomography (TE-OCT) as a potential tool in tissue identification. TE-OCT creates images based on two different forms of contrast: optical reflectance and thermo-elastic deformation. TE-OCT uses short laser pulses to induce thermo-elastic tissue deformation and measures the resulting surface displacement using phase-sensitive OCT. In this work we ...
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  Mentions: Delft University of Technology University of Lübeck Erasmus University
4. Parametric imaging of attenuation by optical coherence tomography: review of models, methods, and clinical translation
  
  Explore SPIE Digital Library Apr 20 2020
  
  Significance: Optical coherence tomography (OCT) provides cross-sectional and volumetric images of backscattering from biological tissue that reveal the tissue morphology. The strength of the scattering, characterized by an attenuation coefficient, represents an alternative and complementary tissue optical property, which can be characterized by parametric imaging of the OCT attenuation coefficient. Over the last 15 years, a multitude of studies have been reported seeking to advance methods to determine the OCT attenuation coefficient and developing them toward clinical applications. Aim: Our review provides an overview of the main models and methods, their assumptions and applicability, together with a survey of preclinical ...
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  Mentions: University of Western Australia Academic Medical Center at the University of Amsterdam Erasmus University
5. Echoes from Picasso: Explanation of an unusual artefact in optical coherence tomography
  
  Explore journals.viamedica.pl Feb 28 2020 Cardiology
  
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  Mentions: Shanghai Jiao Tong University Erasmus University
6. Intravascular Polarimetry in Patients With Coronary Artery Disease
  
  Explore ScienceDirect Nov 22 2019 Cardiology
  
  Objectives The aims of this first-in-human pilot study of intravascular polarimetry were to investigate polarization properties of coronary plaques in patients and to examine the relationship of these features with established structural characteristics available to conventional optical frequency domain imaging (OFDI) and with clinical presentation. Background Polarization-sensitive OFDI measures birefringence and depolarization of tissue together with conventional cross-sectional optical frequency domain images of subsurface microstructure. Methods Thirty patients undergoing polarization-sensitive OFDI (acute coronary syndrome, n = 12; stable angina pectoris, n = 18) participated in this study. Three hundred forty-two cross-sectional images evenly distributed along all imaged coronary arteries were classified into ...
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  Mentions: Massachusetts Institute of Technology Leiden University Massachusetts General Hospital
7. Simultaneous morphological and flow imaging enabled by megahertz intravascular Doppler optical coherence tomography
  
  Explore IEEE Xplore Nov 14 2019 Cardiology
  
  We demonstrate three-dimensional intravascular flow imaging compatible with routine clinical image acquisition workflow by means of megahertz (MHz) intravascular Doppler Optical Coherence Tomography (OCT). The OCT system relies on a 1.1 mm diameter motorized imaging catheter and a 1.5 MHz Fourier Domain Mode Locked (FDML) laser. Using a post processing method to compensate the drift of the FDML laser output, we can resolve the Doppler phase shift between two adjoining OCT A-line datasets. By interpretation of the velocity field as measured around the zero phase shift, the flow direction at specific angles can be qualitatively estimated. Imaging experiments ...
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  Mentions: University of Lübeck Erasmus University Optores
8. Motorized capsule for shadow-free OCT imaging and synchronous beam control
  
  Explore OSA | OSA Publishing Jul 19 2019 Gastroenterology , Probes
  
  We demonstrate a tethered motorized capsule for unobstructed optical coherence tomography (OCT) imaging of the esophagus. By using a distal reflector design, we avoided the common shadow artifact induced by the motor wires. A synchronous driving technique features three types of beam-scanning modes of the capsule, i.e., circumferential beam scanning, localized beam scanning, and accurate beam positioning. We characterized these three modes and carried out ex vivo imaging experiments using the capsule. The results show that the capsule can potentially be a useful tool for diagnostic OCT imaging and OCT-guided biopsy and therapy of the esophagus.
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  Mentions: Massachusetts General Hospital Harvard University Delft University of Technology
9. The Effect of Stent Artefact on Quantification of Plaque Features Using Optical Coherence Tomography (OCT): A Feasibility and Clinical Utility Study
  
  Explore ScienceDirect Jul 7 2019 Cardiology
  
  Background Optical coherence tomography (OCT) can detect detailed plaque features in native coronary arteries. Stent struts cause shadows that partially obscure the vessel wall, but plaque features can still be seen. We investigated the impact of stent artefact on plaque quantification and whether the plaque behind struts is associated with microvascular dysfunction. Methods Patients retrospectively recruited from two centres, underwent OCT pre- and post-stenting on the same vessel segment. Lipid (LA) and calcium (CA) were measured as arcs. Macrophages, microchannels and cholesterol crystals were counted. Subsequently, we determined whether stented plaque features were associated with reduced TIMI flow grade in ...
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  Mentions: University of Western Australia Erasmus University
10. Spontaneous Coronary Artery Dissection: Pathophysiological Insights From Optical Coherence Tomography
  
  Explore ScienceDirect Mar 19 2019 Cardiology
  
  Objectives This study used optical coherence tomography to investigate the mechanism of false lumen (FL) formation in spontaneous coronary artery dissection (SCAD) by studying: 1) differences between fenestrated and nonfenestrated SCAD; 2) vasa vasorum density; and 3) light attenuation characteristics of the FL. Background SCAD is an increasingly recognized cause of acute coronary syndromes , characterized by FL formation and compression of the true lumen (TL). The mechanisms underlying FL formation remain poorly understood. Methods A total of 65 SCAD patients (68 vessels) who underwent acute OCT imaging as part of routine clinical care were included. Images were classified by the ...
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  Mentions: Royal Brompton Hospital San Carlos University Hospital Kings College London
11. Feature Of The Week 09/10/2017: Thermo-elastic Optical Coherence Tomography
  
  Explore Optical Coherence Tomography News Sep 9 2017
  
  The conventional OCT image contrast is derived from elastic scattering, and shows the internal structure of the sample. The determination of the tissue type in OCT images usually depends on the interpretation by the image reader. More accurate tissue type contrast may be achieved by new OCT-based imaging modalities, with sensitivity to other physical parameters than scattering alone. Phase-sensitive OCT can detect tissue motion on nanometer-to- micrometer length scales using the phase of the OCT signal. Depending on the nature of the excitation, different functional images can be reconstructed: a mechanical stimulus yields images of tissue elasticity (optical coherence elastography ...
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  Mentions: Delft University of Technology Chinese Academy of Sciences University of Lübeck
12. Thermo-elastic optical coherence tomography
  
  Explore OSA | OSA Publishing Sep 2 2017
  
  The absorption of nanosecond laser pulses induces rapid thermo-elastic deformation in tissue. A sub-micrometer scale displacement occurs within a few microseconds after the pulse arrival. In this Letter, we investigate the laser-induced thermo-elastic deformation using a 1.5 MHz phase-sensitive optical coherence tomography (OCT) system. A displacement image can be reconstructed, which enables a new modality of phase-sensitive OCT, called thermo-elastic OCT. An analysis of the results shows that the optical absorption is a dominating factor for the displacement. Thermo-elastic OCT is capable of visualizing inclusions that do not appear on the structural OCT image, providing additional tissue type information.
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  Mentions: Delft University of Technology Chinese Academy of Sciences University of Lübeck
13. Intravascular imaging for characterization of coronary atherosclerosis
  
  Explore ScienceDirect Aug 7 2017 Cardiology
  
  This short review surveys recent developments in coronary intravascular imaging technologies. We present an outline of the applications of intravascular imaging for guidance of percutaneous coronary interventions and imaging of atherosclerosis, along with emerging clinical evidence for use. Imaging of tissue composition is important for understanding the relation between the presence of a lesion and clinical sequelae. We describe the recent innovations to enable imaging of unstable atherosclerotic plaques, focusing on the emergence of experimental multimodal imaging technology.
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  Mentions: Massachusetts General Hospital Harvard University UC Davis
14. A new technique for lipid core plaque detection by optical coherence tomography for prevention of peri-procedural myocardial infarction: A case report
  
  Explore LWW Online Jun 17 2017 Cardiology
  
  Rationale: Percutaneous coronary intervention (PCI) provides effective revascularization of atherosclerotic coronary arteries but the invasive nature of treatment can result in complications. Patient concerns: A 53-year old man underwent coronary angiography due to chest pain with minimal ST-segment elevation in the inferior leads of the electrocardiogram. Diagnosis: We proceeded directly to coronary angiography and delineated a moderate stenosis with haziness in the mid right coronary artery (RCA). Interventions: Expert analysis of the pre-intervention OCT imaging demonstrated a large lipid core plaque (LCP), upstream of the culprit site, with minimal thrombus burden. Subsequent implantation of a bioresorbable vascular scaffold, protected with ...
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  Mentions: Erasmus University
15. EuroIntervention Automated characterisation of lipid core plaques in vivo by quantitative optical coherence tomography tissue type imaging
  
  Explore eurointervention.org Dec 23 2016 Cardiology
  
  Aims: Qualitative criteria for plaque tissue characterisation by OCT are well established, but quantitative methods lack systematic validation in vivo . High optical attenuation coefficient µ t has been associated with unstable plaque features, such as lipid core. The purpose of this study was to validate optical coherence tomography (OCT) attenuation imaging for tissue characterisation in vivo , specifically to detect lipid core in coronary atherosclerotic plaques, and to evaluate quantitatively the ability of OCT attenuation imaging to differentiate thin-cap (TCFA) and thick-cap fibroatheroma (FA). Methods and results: We prospectively enrolled 85 patients undergoing imaging of a native coronary segment by both OCT ...
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  Mentions: Massachusetts General Hospital Harvard University Erasmus University
16. Optical coherence tomography attenuation imaging for lipid core detection: an ex-vivo validation study
  
  Explore Home - Springer Sep 14 2016 Cardiology
  
  Lipid-core atherosclerotic plaques are associated with disease progression, procedural complications, and cardiac events. Coronary plaque lipid can be quantified in optical coherence tomography (OCT) pullbacks by measurement of lipid arcs and lipid lengths; parameters frequently used in clinical research, but labor intensive and subjective to analyse. In this study, we investigated the ability of quantitative attenuation, derived from intravascular OCT, to detect plaque lipid. Lipid cores are associated with a high attenuation coefficient. We compared the index of plaque attenuation (IPA), a local quantitative measure of attenuation, to the manually measured lipid score (arc and length) on OCT images, and ...
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  Mentions: Academic Medical Center at the University of Amsterdam Delft University of Technology Erasmus University
17. Heartbeat OCT and Motion-Free 3D In Vivo Coronary Artery Microscopy
  
  Explore imaging.onlinejacc.org May 9 2016 Cardiology
  
  Intravascular optical coherence tomography (IV-OCT) has gained widespread use over the past few years, offering highly detailed images of coronary artery pathologies and interventions (1) . In contrast to the cross-sectional view, longitudinal sections and 3-dimensional (3D) renderings are affected by cardiac motion artifacts and undersampling, complicating interpretation and measurements (2) . We developed Heartbeat OCT, a new OCT method that achieves up to 4,000 frames/s imaging speed for isotropically sampled volume datasets acquired within the diastolic phase of 1 cardiac cycle to restore 3D IV-OCT image fidelity. In this research letter, we present the first in vivo data acquired ...
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  Mentions: University of Lübeck Erasmus University Ludwig-Maximilians University
18. Hybrid intravascular imaging: recent advances, technical considerations, and current applications in the study of plaque pathophysiology
  
  Explore Oxford Journals Apr 28 2016 Cardiology
  
  Cumulative evidence from histology-based studies demonstrate that the currently available intravascular imaging techniques have fundamental limitations that do not allow complete and detailed evaluation of plaque morphology and pathobiology, limiting the ability to accurately identify high-risk plaques. To overcome these drawbacks, new efforts are developing for data fusion methodologies and the design of hybrid, dual-probe catheters to enable accurate assessment of plaque characteristics, and reliable identification of high-risk lesions. Today several dual-probe catheters have been introduced including combined near infrared spectroscopy-intravascular ultrasound (NIRS-IVUS), that is already commercially available, IVUS-optical coherence tomography (OCT), the OCT-NIRS, the OCT-near infrared fluorescence (NIRF) molecular ...
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  Mentions: University of Toronto Imperial College London University College London
19. Safety of optical coherence tomography in daily practice: a comparison with intravascular ultrasound
  
  Explore European Heart Journal Mar 20 2016 Cardiology
  
  Aims Previous studies have reported the safety and feasibility of both time-domain optical coherence tomography (TD-OCT) and Fourier-domain OCT (FD-OCT) in highly selected patients and clinical settings. However, the generalizability of these data is limited, and data in unselected patient populations reflecting a routine cathlab practice are lacking. We compared safety of intracoronary FD-OCT imaging to intravascular ultrasound (IVUS) imaging in a large real-world series of consecutive patients who underwent invasive imaging during coronary catheterization in our centre. Methods and results This is a prospective, single-centre registry of patients scheduled for coronary angiography or intervention undergoing intracoronary imaging with FD-OCT ...
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  Mentions: Erasmus University
20. Feature Of The Week 12/06/2015: Heartbeat Optical Coherence Tomography
  
  Explore Optical Coherence Tomography News Dec 5 2015 Cardiology
  
  Intravascular optical coherence tomography (IV-OCT) has gained widespread use over the past few years, offering highly detailed images of the coronary artery pathologies and interventions. In contrast to the cross-sectional view, longitudinal sections and three-dimensional (3D) renderings are affected by cardiac motion artifacts and undersampling, complicating interpretation and measurements. We developed Heartbeat OCT, a new OCT method that overcomes these issues. This study aims to demonstrate in vivo Heartbeat OCT in a preclinical setting, imaging eliminating cardiac motion artifacts, undersampling and non-uniform rotational distortion, to generate high-quality OCT volumes. Using a micro motor actuated catheter and a MHz sweep rate ...
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  Mentions: Delft University of Technology Chinese Academy of Sciences Erasmus University
21. Heartbeat OCT: in vivo intravascular megahertz-optical coherence tomography
  
  Explore OSA | OSA Publishing Nov 23 2015
  
  Cardiac motion artifacts, non-uniform rotational distortion and undersampling affect the image quality and the diagnostic impact of intravascular optical coherence tomography (IV-OCT). In this study we demonstrate how these limitations of IV-OCT can be addressed by using an imaging system that we called “Heartbeat OCT”, combining a fast Fourier Domain Mode Locked laser, fast pullback, and a micromotor actuated catheter, designed to examine a coronary vessel in less than one cardiac cycle. We acquired in vivo data sets of two coronary arteries in a porcine heart with both Heartbeat OCT, working at 2.88 MHz A-line rate, 4000 frames/s ...
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  Mentions: Delft University of Technology Chinese Academy of Sciences University of Lübeck
22. A Micromotor Catheter for Intravascular Optical Coherence Tomography
  
  Explore engineering.org.cn Jul 14 2015 Cardiology , Probes
  
  We have developed a new form of intravascular optical coherence tomography (IV-OCT) that allows the extremely fast acquisition of high-resolution images of the coronary arteries. This process leads to much better image quality by eliminating cardiac motion artefacts and undersampling. It relies on a catheter that incorporates a synchronous micromotor with a diameter of 1.0 mm and a rotational speed of up to 5600 revolutions per second, enabling an IV-OCT frame rate of 5.6 kHz. This speed is matched by a wavelength-swept laser that generates up to 2.8 million image lines per second. With this setup, our ...
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  Mentions: Delft University of Technology Chinese Academy of Sciences Erasmus University
23. Quantification of fibrous cap thickness in intracoronary optical coherence tomography with a contour segmentation method based on dynamic programming
  
  Explore Home - Springer Mar 6 2015 Cardiology
  
  Objectives Fibrous cap thickness is the most critical component of plaque stability. Therefore, in vivo quantification of cap thickness could yield valuable information for estimating the risk of plaque rupture. In the context of preoperative planning and perioperative decision making, intracoronary optical coherence tomography imaging can provide a very detailed characterization of the arterial wall structure. However, visual interpretation of the images is laborious, subject to variability, and therefore not always sufficiently reliable for immediate decision of treatment. Methods A novel semiautomatic segmentation method to quantify coronary fibrous cap thickness in optical coherence tomography is introduced. To cope with the ...
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  Mentions: Erasmus University
24. OCT Assessment of the Long-Term Vascular Healing Response 5 Years After Everolimus-Eluting Bioresorbable Vascular Scaffold
  
  Explore ScienceDirect Dec 7 2014 Cardiology
  
  Background Although recent observations suggest a favorable initial healing process of the everolimus-eluting bioresorbable vascular scaffold (BVS), little is known regarding long-term healing response. Objectives This study assessed the in vivo vascular healing response using optical coherence tomography (OCT) 5 years after elective first-in-man BVS implantation. Methods Of the 14 living patients enrolled in the Thoraxcenter Rotterdam cohort of the ABSORB A study, 8 patients underwent invasive follow-up, including OCT, 5 years after implantation. Advanced OCT image analysis included luminal morphometry, assessment of the adluminal signal-rich layer separating the lumen from other plaque components, visual and quantitative tissue characterization, and ...
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  Mentions: Erasmus University
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