Automatic characterization of neointimal tissue by intravascular optical coherence tomography

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Dual modality intravascular optical coherence tomography (OCT) and near-infrared fluorescence (NIRF) imaging: a fully automated algorithm for the distance-calibration of NIRF signal intensity for quantitative molecular imaging

Intravascular optical coherence tomography (IVOCT) is a well-established method for the high-resolution investigation of atherosclerosis in vivo. Intravascular near-infrared fluorescence (NIRF) imaging is a novel technique for the assessment of molecular processes associated with coronary artery disease. Integration of NIRF and IVOCT technology in a single catheter provides the capability to simultaneously obtain co-localized anatomical and molecular information from the artery wall. Since NIRF signal intensity attenuates as a function of imaging catheter distance to the vessel wall, the generation of quantitative NIRF data requires an accurate measurement of the vessel wall in IVOCT images. Given that dual modality, intravascular OCT–NIRF systems acquire data at a very high frame-rate (>100 frames/s), a high number of images per pullback need to be analyzed, making manual processing of OCT–NIRF data extremely time consuming. To overcome this limitation, we developed an algorithm for the automatic distance-correction of dual-modality OCT–NIRF images. We validated this method by comparing automatic to manual segmentation results in 180 in vivo images from six New Zealand White rabbit atherosclerotic after indocyanine-green injection. A high Dice similarity coefficient was found (0.97 ± 0.03) together with an average individual A-line error of 22 µm (i.e., approximately twice the axial resolution of IVOCT) and a processing time of 44 ms per image. In a similar manner, the algorithm was validated using 120 IVOCT clinical images from eight different in vivo pullbacks in human coronary arteries. The results suggest that the proposed algorithm enables fully automatic visualization of dual modality OCT–NIRF pullbacks, and provides an accurate and efficient calibration of NIRF data for quantification of the molecular agent in the atherosclerotic vessel wall.National Institutes of Health (U.S.) (NIH R01HL093717)Merck & Co., Inc

A neurovascular high-frequency optical coherence tomography system enables in situ cerebrovascular volumetric microscopy

Intravascular imaging has emerged as a valuable tool for the treatment of coronary and peripheral artery disease; however, no solution is available for safe and reliable use in the tortuous vascular anatomy of the brain. Endovascular treatment of stroke is delivered under image guidance with insufficient resolution to adequately assess underlying arterial pathology and therapeutic devices. High-resolution imaging, enabling surgeons to visualize cerebral arteries\u27 microstructure and micron-level features of neurovascular devices, would have a profound impact in the research, diagnosis, and treatment of cerebrovascular diseases. Here, we present a neurovascular high-frequency optical coherence tomography (HF-OCT) system, including an imaging console and an endoscopic probe designed to rapidly acquire volumetric microscopy data at a resolution approaching 10 microns in tortuous cerebrovascular anatomies. Using a combination of in vitro, ex vivo, and in vivo models, the feasibility of HF-OCT for cerebrovascular imaging was demonstrated

Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies

Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease. Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ∼10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results. Methods: The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings. Results: Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text. Conclusions: This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data

Recent Advances in the Field of Optical Coherence Tomography

© 2017, Springer Science+Business Media New York. Purpose of Review: The scope of this text is to critically review the most important recent advances in the field of optical coherence tomography, both from a clinical, scientific, and technical point of view. Recent Findings: In recent years, important steps forward have been put in the field of optimization of PCI (with a focus on optimal sizing of stents and optimization of stent expansion after implantation) and the differentiation and its possible applications of various underlying morphologic characteristics of acute coronary syndrome lesions. Several efforts have been made to elucidate underlying mechanical causes of stent thrombosis, based on optical coherence tomography (OCT) imaging. This had led to the recognition of neoatherosclerosis as an important cause for very late stent thrombosis, fueling new research into this area and to the development of intracoronary devices which could be even more safe for patients on the very long term. Summary: With an ever increasing use for clinical and scientific applications in coronary artery disease, OCT has come to a mature and solid tool in the armamentarium of the coronary artery disease specialist. With new areas deserving more intensified focus and several innovations ahead, it seems that OCT is there to defend its position as the standard intracoronary imaging modality for the next decennium.status: publishe

Optical Coherence Tomography for Neurovascular Disorders

Diagnosis of cerebrovascular disease includes vascular neuroimaging techniques such as computed tomography (CT) angiography, magnetic resonance (MR) angiography (with or without use of contrast agents) and catheter digital subtraction angiography (DSA). These techniques provide mostly information about the vessel lumen. Vessel wall imaging with MR seeks to characterize cerebrovascular pathology, but with resolution that is often insufficient for small lesions. Intravascular imaging techniques such as ultrasound and optical coherence tomography (OCT), used for over a decade in the peripheral circulation, is not amendable to routine deployment in the intracranial circulation due to vessel caliber and tortuosity. However, advances in OCT technology including the probe profile, stiffness and unique distal rotation solution, holds the promise for eventual translation of OCT into the clinical arena. As such, it is apropos to review this technology and present the rationale for utilization of OCT in the cerebrovasculature

Very late stent thrombosis and longitudinal stent deformation

peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=tacd20status: publishe

Development of 3D IVOCT Imaging and Co-Registration of IVOCT and Angiography in the Catheterization Laboratory

© 2014, Springer Science+Business Media New York. Intravascular optical coherence tomography (IVOCT) has become the imaging modality of choice for the evaluation of coronary artery disease and percutaneous coronary intervention (PCI). Both for clinical practice and research, there is a growing interest in 3-dimensional (3D) visualization, as this gives a more comprehensive and intuitively easier to understand representation, compared with 2-dimensional, cross-sectional images. Integrating 3D-IVOCT with classic X-ray angiographic images offers additional advantages and the prospect of integrating IVOCT in fluoroscopic guidance during PCI. Different vendors of IVOCT technology already provide integrated 3D rendering software in their consoles, making 3D images available at the ‘push-of-a-button’. In this review, we will discuss (1) the basic principles and elaboration of 3D-IVOCT in recent years, (2) the feasibility and potential advantages of co-registration with X-ray angiography, (3) the currently available solutions for 3D imaging and their potential clinical applications, and (4) the ongoing development of applications for advanced 3D visualization.status: publishe

Intracoronary imaging of coronary atherosclerosis: validation for diagnosis, prognosis and treatment.

While coronary atherosclerosis is a leading cause of mortality, evaluation of coronary lesions was previously limited to either indirect angiographic assessment of the lumen silhouette or post mortem investigations. Intracoronary (IC) imaging modalities have been developed that allow for visualization and characterization of coronary atheroma in living patients. Used alone or in combination, these modalities have enhanced our understanding of pathobiological mechanisms of atherosclerosis, identified factors responsible for disease progression, and documented the ability of various medications to reverse the processes of plaque growth and destabilization. These methodologies have established a link between in vivo plaque characteristics and subsequent coronary events, thereby improving individual risk stratification, paving the way for risk-tailored systemic therapies and raising the option for pre-emptive interventions. Moreover, IC imaging is increasingly used during coronary interventions to support therapeutic decision-making in angiographically inconclusive disease, guide and optimize procedural results in selected lesion and patient subsets, and unravel mechanisms underlying stent failure. This review aims to summarize current evidence regarding the role of IC imaging for diagnosis and risk stratification of coronary atherosclerosis, and to describe its clinical role for guiding percutaneous coronary interventions. Future perspectives for in-depth plaque characterization using novel techniques and multimodality imaging approaches are also discussed