Feasibility of Rapidly Creating High Resolution Virtual Three-Dimensional Models of Anomalous Aortic Origin of Coronary Arteries (original) (raw)
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2010
Coronary artery disease contributes to a third of global deaths, afflicting seventeen million individuals in the United States alone. To understand the role of hemodynamics in coronary artery disease and better predict the outcomes of interventions, computational simulations of blood flow can be used to quantify coronary flow and pressure realistically. In this study, we developed a method that predicts coronary flow and pressure of three-dimensional epicardial coronary arteries by representing the cardiovascular system using a hybrid numerical/analytic closed loop system comprising a threedimensional model of the aorta, lumped parameter coronary vascular models to represent the coronary vascular networks, three-element Windkessel models of the rest of the systemic circulation and the pulmonary circulation, and lumped parameter models for the left and right sides of the heart. The computed coronary flow and pressure and the aortic flow and pressure waveforms were realistic as compared to literature data.
Atherosclerosis, 2015
Background: Geometrically-correct 3D OCT is a new imaging modality with the potential to investigate the association of local hemodynamic microenvironment with OCT-derived high-risk features. We aimed to describe the methodology of 3D OCT and investigate the accuracy, inter-and intra-observer agreement of 3D OCT in reconstructing coronary arteries and calculating ESS, using 3D IVUS and 3D QCA as references. Methods-Results: 35 coronary artery segments derived from 30 patients were reconstructed in 3D space using 3D OCT. 3D OCT was validated against 3D IVUS and 3D QCA. The agreement in artery reconstruction among 3D OCT, 3D IVUS and 3D QCA was assessed in 3-mm-long subsegments using lumen morphometry and ESS parameters. The inter-and intra-observer agreement of 3D OCT, 3D IVUS and 3D QCA were assessed in a representative sample of 61 subsegments (n ¼ 5 arteries). The data processing times for each reconstruction methodology were also calculated. There was a very high agreement between 3D OCT vs. 3D IVUS and 3D OCT vs. 3D QCA in terms of total reconstructed artery length and volume, as well as in terms of segmental morphometric and ESS metrics with mean differences close to zero and narrow limits of agreement (BlandeAltman analysis). 3D OCT exhibited excellent inter-and intra-observer agreement. The analysis time with 3D OCT was significantly lower compared to 3D IVUS. Conclusions: Geometrically-correct 3D OCT is a feasible, accurate and reproducible 3D reconstruction technique that can perform reliable ESS calculations in coronary arteries.
3D Modeling of Coronary Artery Bifurcations from CTA and Conventional Coronary Angiography
Lecture Notes in Computer Science, 2011
Coronary artery bifurcations are regions where the atherosclerotic plaque appears more frequently and where the percutaneous treatment is more challenging. To analyze these important vascular regions, in this paper is proposed a method for the extraction of realistic 3D models of coronary bifurcations combining information from pre operative computer tomography angiography (CTA) to obtain the 3D structure of the vessels and pre and post operative conventional coronary angiography (CCA) to extract a more accurate estimation of the lumen radius before and after stenting. The method proposed is semiautomatic, starting from a set of user defined landmarks, and has been successfully applied to data from five patients that underwent endovascular treatment in a coronary bifurcation. The results obtained are satisfactory by visual inspection and in comparison with manual measurements.
Journal of the American College of Cardiology, 2015
Computational fluid dynamics allow virtual evaluation of coronary physiology and shear stress (SS). Most studies hitherto assumed the vessel as a single conduit without accounting for the flow through side branches. This study sought to develop a new approach to reconstruct coronary geometry that also computes outgoing flow through side branches in hemodynamic and biomechanical calculations, using fusion of optical coherence tomography (OCT) and 3-dimensional (3D) angiography. Twenty-one patients enrolled in the DOCTOR (Does Optical Coherence Tomography Optimize Revascularization) fusion study underwent OCT and 3D-angiography of the target vessel (9 left anterior descending, 2 left circumflex, 10 right coronary artery). Coronary 3D reconstruction was performed by fusion of OCT and angiography, creating a true anatomical tree model (TM) including the side branches, and a traditional single-conduit model (SCM) disregarding the side branches. The distal coronary pressure to aortic pres...
Four-dimensional coronary morphology and computational hemodynamics
Medical Imaging 2001: Image Processing, 2001
Conventional reconstructions from intravascular ultrasound (IVUS) stack the frames as acquired during the pullback of the catheter to form a straight three-dimensional volume, thus neglecting the vessel curvature and merging images from different heart phases. We are developing a comprehensive system for fusion of the IVUS data with the pullback path as determined from x-ray angiography, to create a geometrically accurate 4-D (3-D plus time) model of the coronary vasculature as basis for computational hemodynamics. The overall goal of our work is to correlate shear stress with plaque thickness. The IVUS data are obtained in a single pullback using an automated pullback device; the frames are afterwards assigned to their respective heart phases based upon the ECG signal. A set of 3-D models is reconstructed by fusion of IVUS and angiographic data corresponding to the same ECG-gated heart phase; methods of computational fluid dynamics (CFD) are applied to obtain important hemodynamic data. Combining these models yields the final 4-D reconstruction. Visualization is performed using the platform-independent VRML standard for a user-friendly manipulation of the scene. An extension for virtual angioscopy allows an easy assessment of the vessel features within their local context. Validation was successfully performed both in-vitro and in-vivo.
Virtual angioscopy in human coronary arteries with visualization of computational hemodynamics
… and Function from …, 2001
We are presenting a comprehensive system for fusion of intravascular ultrasound (IVUS) data and x-ray angiography, aiming to create a geometrically accurate 3-D or 4-D (3-D plus time) model of the coronary vasculature. For hemodynamic analyses, methods of computational fluid dynamics (CFD) are applied to the reconstructed data, resulting in quantitative estimates of the wall shear stress. Visualization is performed using the Virtual Reality Modeling Language (VRML). Lumen and adventitia borders are modeled as surfaces using indexed face sets; quantitative results are encoded as color per vertex. The endoscopic mode (virtual angioscopy) allows an interactive fly-through animation with variable speed along with arbitrary positioning within the vessel. Since this functionality exceeds those of the standard VRML animation nodes, an external prototype library containing VRML and JavaScript definitions has been developed that provides a 3-D graphical user interface to navigate within the endoscopic mode. The control panel is available on demand, but does neither obstruct any vessel features when not needed, nor does it limit the viewport for the scene. Preliminary results showed a good feasibility of the overall procedure, and a high reliability of the fusion and CFD methods as well as the visualization with the virtual endoscopy VRML library.
Computers in Biology and Medicine, 2013
There is an ongoing research and clinical interest in the development of reliable and easily accessible software for the 3D reconstruction of coronary arteries. In this work, we present the architecture and validation of IVUSAngio Tool, an application which performs fast and accurate 3D reconstruction of the coronary arteries by using intravascular ultrasound (IVUS) and biplane angiography data. The 3D reconstruction is based on the fusion of the detected arterial boundaries in IVUS images with the 3D IVUS catheter path derived from the biplane angiography. The IVUSAngio Tool suite integrates all the intermediate processing and computational steps and provides a user-friendly interface. It also offers additional functionality, such as automatic selection of the end-diastolic IVUS images, semi-automatic and automatic IVUS segmentation, vascular morphometric measurements, graphical visualization of the 3D model and export in a format compatible with other computer-aided design applications. Our software was applied and validated in 31 human coronary arteries yielding quite promising results. Collectively, the use of IVUSAngio Tool significantly reduces the total processing time for 3D coronary reconstruction. IVUSAngio Tool is distributed as free software, publicly available to download and use.
Computational simulation of intracoronary flow based on real coronary geometry
European Journal of Cardio-thoracic Surgery, 2004
Objective: To assess the feasibility of computationally simulating intracoronary blood flow based on real coronary artery geometry and to graphically depict various mechanical characteristics of this flow. Methods: Explanted fresh pig hearts were fixed using a continuous perfusion of 4% formaldehyde at physiological pressures. Omnipaque dye added to lead rubber solution was titrated to an optimum proportion of 1:25, to cast the coronary arterial tree. The heart was stabilized in a phantom model so as to suspend the base and the apex without causing external deformation. High resolution computerized tomography scans of this model were utilized to reconstruct the threedimensional coronary artery geometry, which in turn was used to generate several volumetric tetrahedral meshes of sufficient density needed for numerical accuracy. The transient equations of momentum and mass conservation were numerically solved by employing methods of computational fluid dynamics under realistic pulsatile inflow boundary conditions. Results: The simulations have yielded graphic distributions of intracoronary flow stream lines, static pressure drop, wall shear stress, bifurcation mass flow ratios and velocity profiles. The variability of these quantities within the cardiac cycle has been investigated at a temporal resolution of 1/100th of a second and a spatial resolution of about 10 mm. The areas of amplified variations in wall shear stress, mostly evident in the neighborhoods of arterial branching, seem to correlate well with clinically observed increased atherogenesis. The intracoronary flow lines showed stasis and extreme vorticity during the phase of minimum coronary flow in contrast to streamlined undisturbed flow during the phase of maximum flow. Conclusions: Computational tools of this kind along with a state-of-the-art multislice computerized tomography or magnetic resonance-based noninvasive coronary imaging, could enable realistic, repetitive, non-invasive and multidimensional quantifications of the effects of stenosis on distal hemodynamics, and thus help in precise surgical/interventional planning. It could also add insights into coronary and bypass graft atherogenesis. q