1. Articles from gijs van soest

    1-24 of 44 1 2 »
    1. Simultaneous morphological and flow imaging enabled by megahertz intravascular Doppler optical coherence tomography

      Simultaneous morphological and flow imaging enabled by megahertz intravascular Doppler optical coherence tomography

      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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    2. Motorized capsule for shadow-free OCT imaging and synchronous beam control

      Motorized capsule for shadow-free OCT imaging and synchronous beam control

      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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    3. The Effect of Stent Artefact on Quantification of Plaque Features Using Optical Coherence Tomography (OCT): A Feasibility and Clinical Utility Study

      The Effect of Stent Artefact on Quantification of Plaque Features Using Optical Coherence Tomography (OCT): A Feasibility and Clinical Utility Study

      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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    4. Spontaneous Coronary Artery Dissection: Pathophysiological Insights From Optical Coherence Tomography

      Spontaneous Coronary Artery Dissection: Pathophysiological Insights From Optical Coherence Tomography

      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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    5. Feature Of The Week 09/10/2017: Thermo-elastic Optical Coherence Tomography

      Feature Of The Week 09/10/2017: Thermo-elastic  Optical Coherence Tomography

      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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    6. Thermo-elastic optical coherence tomography

      Thermo-elastic optical coherence tomography

      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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    7. Intravascular imaging for characterization of coronary atherosclerosis

      Intravascular imaging for characterization of coronary atherosclerosis

      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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    8. A new technique for lipid core plaque detection by optical coherence tomography for prevention of peri-procedural myocardial infarction: A case report

      A new technique for lipid core plaque detection by optical coherence tomography for prevention of peri-procedural myocardial infarction: A case report

      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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    9. EuroIntervention Automated characterisation of lipid core plaques in vivo by quantitative optical coherence tomography tissue type imaging

      EuroIntervention Automated characterisation of lipid core plaques in vivo by quantitative optical coherence tomography tissue type imaging

      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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    10. Optical coherence tomography attenuation imaging for lipid core detection: an ex-vivo validation study

      Optical coherence tomography attenuation imaging for lipid core detection: an ex-vivo validation study

      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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    11. Heartbeat OCT and Motion-Free 3D In Vivo Coronary Artery Microscopy

      Heartbeat OCT and Motion-Free 3D In Vivo Coronary Artery Microscopy

      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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    12. Hybrid intravascular imaging: recent advances, technical considerations, and current applications in the study of plaque pathophysiology

      Hybrid intravascular imaging: recent advances, technical considerations, and current applications in the study of plaque pathophysiology

      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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    13. Safety of optical coherence tomography in daily practice: a comparison with intravascular ultrasound

      Safety of optical coherence tomography in daily practice: a comparison with intravascular ultrasound

      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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    14. Feature Of The Week 12/06/2015: Heartbeat Optical Coherence Tomography

      Feature Of The Week 12/06/2015: Heartbeat Optical Coherence Tomography

      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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    15. Heartbeat OCT: in vivo intravascular megahertz-optical coherence tomography

      Heartbeat OCT: in vivo intravascular megahertz-optical coherence tomography

      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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    16. A Micromotor Catheter for Intravascular Optical Coherence Tomography

      A Micromotor Catheter for Intravascular Optical Coherence Tomography

      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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    17. Quantification of fibrous cap thickness in intracoronary optical coherence tomography with a contour segmentation method based on dynamic programming

      Quantification of fibrous cap thickness in intracoronary optical coherence tomography with a contour segmentation method based on dynamic programming

      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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    18. OCT Assessment of the Long-Term Vascular Healing Response 5 Years After Everolimus-Eluting Bioresorbable Vascular Scaffold

      OCT Assessment of the Long-Term Vascular Healing Response 5 Years After Everolimus-Eluting Bioresorbable Vascular Scaffold

      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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    19. Development of Tissue Characterization Using Optical Coherence Tomography for Defining Coronary Plaque Morphology and the Vascular Responses After Coronary Stent Implantation

      Development of Tissue Characterization Using Optical Coherence Tomography for Defining Coronary Plaque Morphology and the Vascular Responses After Coronary Stent Implantation

      Cardiovascular disease is associated with a high burden of mortality secondary to acute coronary events. Assessment for vulnerable plaque and an understanding of the etiology of stent failure by intravascular imaging may facilitate a greater understanding of the underlying processes responsible for adverse clinical outcomes and guide future therapy. This review focuses on the role of optical coherence tomography in tissue characterization and highlights future advances within the field providing potential enhancement of image interpretation.

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    20. Effect of temperature and fixation on the optical properties of atherosclerotic tissue: a validation study of an ex-vivo whole heart cadaveric model

      Effect of temperature and fixation on the optical properties of atherosclerotic tissue: a validation study of an ex-vivo whole heart cadaveric model

      Atherosclerotic plaque composition can be imaged using the optical attenuation coefficient derived from intravascular optical coherence tomography (OCT) data. The relation between optical properties and tissue type has been established on autopsy tissues. In this study, we validate an ex-vivo model for the effect of temperature and tissue fixation on optical parameters. We studied the optical attenuation of human coronary arteries at three temperatures, before and after formalin fixation. We developed an en-face longitudinal display of attenuation data of the OCT pullbacks. Using the unfixed, body-temperature condition image as a standard, and after extensive registration with other condition images, we ...

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    21. Quantitative optical coherence tomography tissue-type imaging for lipid-core plaque detection

      Quantitative optical coherence tomography tissue-type imaging for lipid-core plaque detection

      Comparison Between OCT Attenuation Imaging and NIRS for 3 Sites (A) NIRS/IVUS images; (B) OCT and (C) Attenuation coefficient analyzed from the OCT data (color coded 0–12 mm-1). Scale bars are 1 mm. Site 1 (refer to Fig. 1 ): a mixed lesion contains calcifications (bright echos on IVUS with dorsal shadowing; 3–5 o'clock) and lipid-rich tissue (5–10 o'clock). High attenuation (red-orange-yellow) in the plaque (white arrow) coincides with the yellow in the NIRS data. The calcification (marked by c) identified on IVUS and OCT has low attenuation (blue) . Site 2: an eccentric lipid-core plaque ...

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    22. Feature Of The Week 6/30/13: Ultrafast Intravascular Optical Coherence Tomography Imaging

      Feature Of The Week 6/30/13: Ultrafast Intravascular Optical Coherence Tomography Imaging

      The fastest commercial intravascular optical coherence tomography (OCT) systems acquire 160 frames/second with 500 lines/frame, and the pullback speed is limited to 40 mm∕s. In this situation, the images are under sampled in the pullback direction: Only 12% of the lumen is sampled because the sampling interval of 250 μm is much larger than the transverse resolution, which is approximately 30 μm. In clinical situations, the cardiac motion also affects the OCT acquisition. The pullback procedure for the whole artery takes several seconds. The cardiac motion during acquisition will cause inaccuracy in frame spacing and possibly frame ...

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    23. Ultrahigh-speed intravascular optical coherence tomography imaging at 3200 frames per second

      Ultrahigh-speed intravascular optical coherence tomography imaging at 3200 frames per second

      We demonstrated intravascular OCT imaging with frame rate up to 3.2 kHz (192,000 rpm scanning). This was achieved by using a custom-built catheter in which the circumferential scanning was actuated by a 1.0 mm diameter synchronous motor. The OCT system was based on a Fourier Domain Mode Locked laser operating at an A-line rate of 1.6 MHz. The diameter of the catheter was 1.1 mm at the tip. Ex vivo images of human coronary artery (~78.4 mm length) were acquired at a pullback speed of 100 mm/s. True 3D volumetric imaging of the ...

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    24. Intravascular optical coherence tomography imaging at 3200 frames per second

      Intravascular optical coherence tomography imaging at 3200 frames per second

      We demonstrate intravascular optical coherence tomography (OCT) imaging with frame rate up to 3.2 kHz (192,000 rpm scanning). This was achieved by using a custom-built catheter in which the circumferential scanning was actuated by a 1.0 mm diameter synchronous motor. The OCT system, with an imaging depth of 3.7 mm (in air), is based on a Fourier domain mode locked laser operating at an A-line rate of 1.6 MHz. The diameter of the catheter is 1.1 mm at the tip. Ex vivo images of human coronary artery (78.4 mm length) were acquired at ...

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    Quantitative Ex Vivo and In Vivo Comparison of Lumen Dimensions Measured by Optical Coherence Tomography and Intravascular Ultrasound in Human Coronary Arteries Witnessed Coronary Plaque Rupture During Cardiac Catheterization Optics In Cardiology Symposium December 1st, 2011 Consensus Standards for Acquisition, Measurement, and Reporting of Intravascular Optical Coherence Tomography Studies: A Report From the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation Feature Of The Week 6/30/13: Ultrafast Intravascular Optical Coherence Tomography Imaging A Micromotor Catheter for Intravascular Optical Coherence Tomography Feature Of The Week 12/06/2015: Heartbeat Optical Coherence Tomography Feature Of The Week 09/10/2017: Thermo-elastic  Optical Coherence Tomography Optical Coherence Tomography Angiography Assessed Retinal and Choroidal Microvasculature Features in Patients with Retinitis Pigmentosa: A Meta-Analysis The vascular densities of the macula and optic disc in normal eyes from children by optical coherence tomography angiography Three-dimensional choroidal vascularity index in acute central serous chorioretinopathy using swept-source optical coherence tomography Optical coherence tomography angiography assessment of retinal microvascular changes in diabetic eyes in an urban safety-net hospital