3D Reconstruction Of Coronary Arteries Research Articles

Rapid automated lumen segmentation of coronary optical coherence tomography images followed by 3D reconstruction of coronary arteries.

Optical coherence tomography has emerged as an important intracoronary imaging technique for coronary artery disease diagnosis as it produces high-resolution cross-sectional images of luminal and plaque morphology. Precise and fast lumen segmentation is essential for efficient OCT morphometric analysis. However, due to the presence of various image artifacts, including side branches, luminal blood artifacts, and complicated lesions, this remains a challenging task. Our research study proposes a rapid automatic segmentation method that utilizes nonuniform rational B-spline to connect limited pixel points and identify the edges of the OCT lumen. The proposed method suppresses image noise and accurately extracts the lumen border with a high correlation to ground truth images based on the area, minimal diameter, and maximal diameter. We evaluated the method using 3300 OCT frames from 10 patients and found that it achieved favorable results. The average time taken for automatic segmentation by the proposed method is 0.17s per frame. Additionally, the proposed method includes seamless vessel reconstruction following the lumen segmentation. The developed automated system provides an accurate, efficient, robust, and user-friendly platform for coronary lumen segmentation and reconstruction, which can pave the way for improved assessment of the coronary artery lumen morphology.

Murray law-based quantitative flow ratio for assessment of left main bifurcation derived from a single fluoroscopic angiographic view as compared to FFRCT

Abstract Background In patients with complex CAD, the presence of left main (LM) disease is an important prognostic factor in assessing the risk balance between PCI and CABG. Functional assessment has become standard of care to evaluate the significance of coronary stenosis and to justify the performance of PCI in the contemporary practice. FFRCT is a well-established method based on 3D reconstruction of coronary artery derived from CCTA. The Murray law-based quantitative flow reserve (μQFR) is a novel computational method of invasive angiography relying on a single angiographic view that takes into account side branches diameters to compute fractal flow division. The aim of the current analysis is to evaluate in patients with complex CAD the feasibility of μQFR in LM bifurcation and its diagnostic concordance with FFRCT. The impact of the optimal viewing angle defined by CCTA on the physiological assessment of the LM bifurcation using a single angiographic view was also evaluated. Methods In 299 consecutive patients with 3-vessel disease with or without LM coronary artery disease, up to 3 analyzable fluoroscopic projections per patient were analysed with μQFR retrospectively. FFRCT and μQFR were measured at 3 fiducial landmark points: i) point of LM bifurcation (POB); ii) proximal LAD 10 mm distal to POB; ii) proximal LCX 10 mm distal to POB. CCTA-based “optimal viewing angle” of LM bifurcation are computed by creating a 3-point closed spline involving the LM, LAD, and LCX at 5mm from the POB and subsequently by reconstructing the “en face” fluoroscopic viewing angle of the spline. The en face viewing angle provides an optimal assessment of the bifurcation geometry [1]. In terms of Rx gantry angulation, the closest angiographic projection to the optimal viewing angle derived from CCTA was defined as the “best fluoroscopic projection” for each patient. Results In 299 patients, 793 projections were analysed with μQFR and compared to FFRCT. Single view μQFR was analyzable in 100%. Correlation and agreement between μQFR and FFRCT for 793 projections in 299 patients are shown in Figure 1A, 2A. The Spearman's correlation coefficient showed moderate correlations at POB (r=0.481, p<0.001) and LCX (r=0.584, p<0.001), and strong correlation at LAD (r=0.642, p<0.001). Correlation and agreement between μQFR and FFRCT for best projections from each patient are shown in Figure 1B, 2B. Correlations were improved in the best projections with the following Spearman's correlation coefficient: at POB (r=0.522, p<0.001), LCX (r=0.622, p<0.001), and LAD (r=0.695, p<0.001). Conclusion Computation of μQFR from a single angiographic view has a high feasibility. Tailored optimal fluoroscopic view is essential for the physiological assessment of the LM bifurcation using a single angiographic view. Evaluation of diagnostic accuracy of μQFR warrants further analysis of the LMCAD after prospective planning of the optimal fluoroscopic view based on the selection of the best CCTA 3D view. Funding Acknowledgement Type of funding sources: None.

3D reconstruction of coronary arteries using deep networks from synthetic X-ray angiogram data

Cardiovascular disease (CVD) is one of the most common health problems that are responsible for one-third of all deaths around the globe. Although X-Ray angiography has deficiencies such as two-dimensional (2D) representation of three dimensional (3D) structures, vessel overlapping, noisy background, the existence of other tissues/organs in images, etc., it is used as the gold standard technique for the diagnosis and in some cases treatment of CVDs. To overcome the deficiencies, great efforts have been drawn on retrieval of actual 3D representation of coronary arterial tree from 2D X-ray angiograms. However, the proposed algorithms are based on analytical methods and enforce some constraints. With the evolution of deep neural networks, 3D reconstruction from images can be achieved effectively. In this study, we propose a new data structure for the representation of objects in a tubular shape for 3D reconstruction of arteries using deep learning. Moreover, we propose a method to generate synthetic coronaries from data of real subjects. Then, we validate tubular shape representation using 3 typical deep learning architectures with synthetic X-ray data we produced. The input to deep learning architectures is multi-view segmented X-Ray images and the output is the structured tubular representation. We compare results qualitatively in terms of visual appearance and quantitatively in terms of Chamfer Distance and Mean Squared Error. The results demonstrate that tubular representation has promising performance in 3D reconstruction of coronaries. We observe that convolutional neural network (CNN) based architectures yield better 3D reconstruction performance with 9.9e-3 on Chamfer Distance. On the other hand, LSTM-based network fails to learn the coronary tree structure and we conclude that LSTMs are not appropriate for auto-regression problems as depicted in this study.

Three-dimensional evaluation of the spatial morphology of stented coronary artery segments in relation to restenosis

To investigate the correlations between the three-dimensional (3D) parameters of target coronary artery segments and restenosis after stent implantation. Sixty-four patients after single, cobalt chromium platform stent (27 BM stents and 37 DES) implantation were investigated retrospectively 12 ± 6 months after the index procedure. 3D coronary artery reconstruction was performed before and after the stent implantation using appropriate projections by a dedicated reconstruction software. The curve of the target segment was characterized by the ratio of the vessel length measured at midline (arc: A) and the distance between the edge points of the stent (chord: C): A/C ratio (ACr). Age, diabetes and hyperlipidaemia were taken into account for the statistical evaluation. 22 patients were diagnosed with ISR, while 42 patients without any restenosis served as controls. The two groups did not differ regarding major cardiovascular risk factors, proportion of the treated vessels or the type of stents. Higher initial ACr values were associated with greater straightening of the vessel curvature in all groups (p < 0.001). Significant negative correlations were found in cases of proximal or distal edge bending angles (p < 0.001). Pre-stent edge bending angles < 7° often showed an increase after the stent implantation, while in case of higher initial values, the bending angles generally decreased. Using multivariate logistic regression modelling we found that the pre-stent ACr was an independent predictor of in-stent restenosis (odds ratio for 1% increase of the ACr: 1.08; p = 0.012). Changes of angles at the stent edges following stent implantation correlate with the initial local bending angles. The ACr predispose to chronic shear stress in the vessel wall, which may contribute to the pathological intimal proliferation.

On the Image-Based Non-Invasive Diagnosis of Cardiovascular Diseases

Cardiovascular diseases are the leading cause of human deaths worldwide. Traditional diagnostic tools of cardiovascular diseases are either based on 2D static medical images, or invasive, bringing troubles to both patients and doctors. Our team is committed to the development of image-based non-invasive diagnostic system for cardiovascular diseases. We have made progress mainly in the following areas: 1) 4D flow technology for heart and large blood vessels. According to MRI 4D Flow data, three-dimensional velocity fields within blood vessels were constructed. Divergence-fee smoothing (DFS) was proposed to eliminate the high frequency noise in the hemodynamic flow field, and make the smoothed velocity field to satisfy the divergence-free condition. The vascular wall shear stress, pressure and other physiological indicators were obtained, their accuracy can meet the need of clinical applications. 2) Accurate noninvasive diagnostic techniques for coronary arterial disease. According to coronary CTA imaging data, 3D reconstruction of coronary arteries was achieved coronary stenosis and plaque lesion were identified and analyzed. Coronary microcirculation was modeled using a 0d model; the coronary artery FFR were computed through the Fast FFR technique, which was based on the reduced-order computational fluid dynamics (CFD). The Fast FFR technique can compute the FFR within 5 minutes. Similar techniques have been used in the preoperative evaluation of intraluminal artery bypass. 3) In vitro evaluation of artificial heart valves and blood-contacting artificial organs. High-fidelity CFD and PIV technique were developed to study the flow field in the artificial heart valve and blood pumps. In vitro platform for experimentally and numerically evaluate the blood damage were also developed.

3D reconstruction of coronary arteries from 2D angiographic projections using non-uniform rational basis splines (NURBS) for accurate modelling of coronary stenoses.

ObjectiveAssessment of coronary stenosis severity is crucial in clinical practice. This study proposes a novel method to generate 3D models of stenotic coronary arteries, directly from 2D coronary images, and suitable for immediate assessment of the stenosis severity.MethodsFrom multiple 2D X-ray coronary arteriogram projections, 2D vessels were extracted. A 3D centreline was reconstructed as intersection of surfaces from corresponding branches. Next, 3D luminal contours were generated in a two-step process: first, a Non-Uniform Rational B-Spline (NURBS) circular contour was designed and, second, its control points were adjusted to interpolate computed 3D boundary points. Finally, a 3D surface was generated as an interpolation across the control points of the contours and used in the analysis of the severity of a lesion. To evaluate the method, we compared 3D reconstructed lesions with Optical Coherence Tomography (OCT), an invasive imaging modality that enables high-resolution endoluminal visualization of lesion anatomy.ResultsValidation was performed on routine clinical data. Analysis of paired cross-sectional area discrepancies indicated that the proposed method more closely represented OCT contours than conventional approaches in luminal surface reconstruction, with overall root-mean-square errors ranging from 0.213mm2 to 1.013mm2, and maximum error of 1.837mm2. Comparison of volume reduction due to a lesion with corresponding FFR measurement suggests that the method may help in estimating the physiological significance of a lesion.ConclusionThe algorithm accurately reconstructed 3D models of lesioned arteries and enabled quantitative assessment of stenoses. The proposed method has the potential to allow immediate analysis of the stenoses in clinical practice, thereby providing incremental diagnostic and prognostic information to guide treatments in real time and without the need for invasive techniques.

3D Coronary Artery Reconstruction by 2D Motion Compensation Based on Mutual Information

Background3D reconstruction of the coronary arteries can provide more information in the interventional surgery. Motion compensation is one kind of the 3D reconstruction method. MethodsWe propose a novel and complete 2D motion compensated reconstruction method. The main components include initial reconstruction, forward projection, registration and compensated reconstruction. We apply the mutual information (MI) and rigidity penalty (RP) as registration measure. The advanced adaptive stochastic gradient descent (ASGD) is adopted to optimize this cost function. We generate the maximum forward projection by the simplified distance driven (SDD) projector. The compensated reconstruction adopts the MAP iterative reconstruction algorithm which is based on L0 prior. ResultsComparing with the ECG-gating reconstruction and other reference method, the evaluation indicates that the proposed 2D motion compensation leads to a better 3D reconstruction for both the rest and stronger motion phases. The algorithm compensates the residual motion and reduces the artifact largely. As the gating window width increases, the overall image noise decreases and the contrast of the vessels improves. ConclusionsThe proposed method improved the 3D reconstruction quality and reduced the artifact level. The considerable improvement in the image quality results from motion compensation increases the clinical usability of 3D coronary artery.

3D reconstruction of coronary arteries and atherosclerotic plaques based on computed tomography angiography images

The purpose of this study is to present a new semi-automated methodology for three-dimensional (3D) reconstruction of coronary arteries and their plaque morphology using Computed Tomography Angiography (CTA) images. The methodology is summarized in seven stages: pre-processing of the acquired CTA images, extraction of the vessel tree centerline, estimation of a weight function for lumen, outer wall and calcified plaque, lumen segmentation, outer wall segmentation, plaque detection, and finally 3D surfaces construction. The methodology was evaluated using both expert manual annotations and estimations of a recently presented Intravascular Ultrasound (IVUS) reconstruction method. As far as the manual annotation validation process is concerned, the mean value of the comparison metrics for the 3D segmentation were 0.749 and 1.746 for the Dice coefficient and Hausdorff distance, respectively. On the other hand, the correlation coefficients for the degree of stenosis 1, the degree of stenosis 2, the plaque burden, the minimal lumen area and the minimal lumen diameter, when comparing the derived from the proposed methodology 3D models with the IVUS reconstructed models, were 0.79, 0.77, 0.75, 0.85, 0.81, respectively. The proposed methodology is an innovative approach for reconstruction of coronary arteries, since it provides 3D models of the lumen, the outer wall and the CP plaques, using the minimal user interaction. Its first implementation demonstrated that it provides an accurate reconstruction of coronary arteries and thus, it may have a wide clinical applicability

Local motion-compensated method for high-quality 3D coronary artery reconstruction.

The 3D reconstruction of coronary artery from X-ray angiograms rotationally acquired on C-arm has great clinical value. While cardiac-gated reconstruction has shown promising results, it suffers from the problem of residual motion. This work proposed a new local motion-compensated reconstruction method to handle this issue. An initial image was firstly reconstructed using a regularized iterative reconstruction method. Then a 3D/2D registration method was proposed to estimate the residual vessel motion. Finally, the residual motion was compensated in the final reconstruction using the extended iterative reconstruction method. Through quantitative evaluation, it was found that high-quality 3D reconstruction could be obtained and the result was comparable to state-of-the-art method.

Shape context and projection geometry constrained vasculature matching for 3D reconstruction of coronary artery

Vascular structure matching in X-ray angiographic images sequence obtained at different imaging angles is important for identifying vascular structures in computer-assisted diagnosis of coronary artery diseases. In this paper, a novel shape context and projection geometry constraint method is proposed for soft matching and identification of coronary artery structures. Firstly, the matching energy function between vasculatures in different angiographic views is constructed based on the local geometry constraint and perspective projection constraint. Secondly, initial matching of the vasculatures is established by the shape context constraint. Thirdly, the deterministic annealing method is used to optimize the matching function. Hence, optimal correspondences are obtained by iteratively reducing the temperature of the optimization function. Finally, on the basis of the obtained correspondences, 3D coronary artery structure can be reconstructed according to the theory of binocular stereo vision in computer vision. Experiments show that the relationship among the different views can be accurately constructed by the proposed method. The proposed method is fully automatic, so it can assist physician to rapidly identify and correlate vascular structures from angiographic images obtained at different imaging angles.

WE‐G‐207‐01: Motion‐Compensated Iterative Reconstruction of Coronary Artery Based On 3D/2D Deformable Image Registration

Purpose:The 3D reconstruction of coronary artery from x‐ray angiograms rotationally acquired on c‐arm is a challenging task because of the vessel motion. While ECG gated reconstruction have shown promising results, residual vessel motion exists because of imperfect gating or irregular motion, and affects the reconstruction quality. The purpose of this work is to propose and validate a new motion‐compensated reconstruction method to reduce the effect of residual vessel motion.Methods:The proposed method consisted of three main steps. First, a subset of angiograms were selected using nearest‐neighbor ECG gating and used to perform the initial reconstruction based on a L1 and total variation regularized iterative reconstruction method. Due to the residual vessel motion, the initial Result exhibited motion artifacts which hindered its clinical usage. Next, a novel 3D/2D registration method was proposed to estimate the vessel motion between the initial reconstruction and the vessel morphology corresponding to each angiogram. Finally, a regularized iterative reconstruction method with motion‐compensation was proposed to reconstruct the final Result.Results:The proposed method was evaluated using three groups of simulated ECG‐gated angiograms with increasing amount of residual vessel motion. The reconstruction results of the proposed method were quantitatively evaluated using Maximum Mean Overlap (MMO) and Relative Radius Error (RRE) metrics, where larger MMO value and smaller RRE value means a better reconstruction. The MMOs (ECG gated reconstruction vs. motion‐compensated reconstruction) for the three groups were (0.94, 0.87, 0.79) vs. (0.96, 0.93, 0.89); The RREs were (7.7, 15.6, 23.3) vs. (4.2, 4.3, 7.1). The reconstruction Result was comparable to that of state‐of‐the‐art method.Conclusion:We have developed and validated a motion‐compensated reconstruction method to handle the residual vessel motion which degrades the ECG gated reconstruction. The method could effectively estimate and compensate the vessel motion, and thus improve the reconstruction quality.

Computer methods for follow-up study of hemodynamic and disease progression in the stented coronary artery by fusing IVUS and X-ray angiography.

Despite a lot of progress in the fields of medical imaging and modeling, problem of estimating the risk of in-stent restenosis and monitoring the progress of the therapy following stenting still remains. The principal aim of this paper was to propose architecture and implementation details of state of the art of computer methods for a follow-up study of disease progression in coronary arteries stented with bare-metal stents. The 3D reconstruction of coronary arteries was performed by fusing X-ray angiography and intravascular ultrasound (IVUS) as the most dominant modalities in interventional cardiology. The finite element simulation of plaque progression was performed by coupling the flow equations with the reaction-diffusion equation applying realistic boundary conditions at the wall. The alignment of baseline and follow-up data was performed automatically by temporal alignment of IVUS electrocardiogram-gated frames. The assessment was performed using three six-month follow-ups of right coronary artery. Simulation results were compared with the ground truth data measured by clinicians. In all three data sets, simulation results indicated the right places as critical. With the obtained difference of 5.89 ± ~4.5% between the clinical measurements and the results of computer simulations, we showed that presented framework is suitable for tracking the progress of coronary disease, especially for comparing face-to-face results and data of the same artery from distinct time periods.

IVUSAngio Tool: A publicly available software for fast and accurate 3D reconstruction of coronary arteries

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.

Electrophysiological characteristic and ablation of epicardial idiopathic ventricular arrhythmias arising around left fibrous triangle

Background: The success rate of radiofrequency catheter ablation of ventricular arrhythmias originating from Left Fibrous Triangle (LFT) is not high. This article was to discuss the characteristics of surface electrocardiogram and the strategy of ablation of ventricular arrhythmias originating from LFT. Methods: From February 2002 to March 2012, total 323 patients with outflow ventricular arrhythmias were ablated in our hospital, including 46 patients whose ventricular arrhythmias originated from the LFT. The mean age of the 46 patients was 44±13 years (16-87 years), and 24 of them (52.2%) were male. Thirty patients had frequent premature ventricular contractions (PVCs) and 16 patients had both PVCs and nonsustained or sustained ventricular tachycardia (VT). All the patients were examined with ECG, electrophysiology, active mapping and pace mapping. The computer tomography angiogram (CTA) 3D reconstruction of coronary artery, venous was completed in 20 patients. Results: Successful ablation was achieved in 41 of the 46 patients (89.1%, 41/46) targeting left coronary cusp (LCC, 30 patients), infra aortic valve (infra AV, 6 patients) and great cardiac vein (GCV, 5 patients). The surface ECG in all the three groups presented with inferior axis and R/S-transition in lead V1 and V2. There were no differences in the total QRS duration in the three groups. Most of the patients presented with right bundle branch block (RBBB) morphology in infra AV group and GCV group compared with LCC group (67%,80% vs 15%, P=0.002). Regarding to the classification of the LFT according to CTA, the patterns of distribution were as follows: closed in 10 (50%, 10/20) hearts; completely opened in 2 (10%, 2/20); inferiorly opened in 5 (25%, 5/20) hearts and superiorly opened in 1 (5%, 1/20) hearts. In the remaining 2 (10%, 2/20), there were not any distances between GCV and left coronary artery. The closest distance between the corner of the GCV and LCC is 17.6±4.2 mm (9.1mm∼26.3mm). Conclusions: Ventricular arrhythmias originating from the LFT can be ablated in the nadir of the LCC, infra AV and the GCV. The success rate may be impacted by the distance from the GCV and the LCC.

GW24-e1769 Electrophysiological characteristic and ablation of epicardial idiopathic ventricular arrhythmias arising around left fibrous triangle

ObjectivesThe success rate of radiofrequency catheter ablation of ventricular arrhythmias originating from left fibrous triangle (LFT) is not high. This article was to discuss the characteristics of sueface electrocardiogram and...

ASSA13-02-4 Electrophysiological Characteristic and Ablation of Epicardial Idiopathic Ventricular Arrhythmias Arising Around Left Fibrous Triangle

Background The success rate of radiofrequency catheter ablation of ventricular arrhythmias originating from left fibrous triangle (LFT) is not high. This article was to discuss the characteristics of sueface electrocardiogram and the strategy of ablation of ventricular arrhythmias originating from LFT. Methods From February 2002 to March 2012, total 323 patients with outflow ventricular arrhythmias were ablated in our hospital, incluing 46 patients whose ventricular arrhythmias originated from the LFT. The mean age of the 46 patients was 44 ± 13 years (16–87 years), and 24 of them (52.2%) were male. Thirty patients had frequent premature ventricular contractions (PVCs) and 16 patients had both PVCs and nonsustained or sustained ventricular tachycardia (VT). All the patients were examined with ECG, electrophysiology, active mapping and pace mapping. The computer tomography angiogram (CTA) 3D reconstruction of coronary artery, venouswas completed in 20 patients. Results Successful ablation was achieved in 41 of the 46 patients (89.1%, 41/46) targeting left coronary cusp (LCC, 30 patients), infra aortic valve (infra AV, 6 patients) and great cardiac vein (GCV, 5 patients). The surface ECG in all the three groups presented with inferior axis and R/S-transition in lead V1 and V2. There were no differentces in the total QRS duration in the three groups. Most of the patients presented with right bundle branch block (RBBB) morphology in infra AV group and GCV group compared with LCC group (67%, 80% vs 15%, P = 0.002). Regarding to the classification of the LFT according to CTA, the patterns of distribution were as follows: “closed” in 10 (50%, 10/20) hearts; “completely opened” in 2 (10%, 2/20); “inferiorly opened” in 5 (25%, 5/20) hearts and “superiorly opened” in 1 (5%, 1/20) hearts. In the remaining 2 (10%, 2/20), there were not any distances between cardiac vein and artery. The closest distance between the corner of the GCV and LCC is 17.6 ± 4.2 mm (9.1mm ∼ 26.3mm). Conclusions Ventricular arrhythmias originating from the LFT can be ablated in the nadir of the LCC, infra AV and the GCV. The success rate may be impacted by the distance from the GCV and the LCC.

Abstract 347: Early Drug-Induced Inhibition of Proatherogenic Genes in Coronary Regions of Low Endothelial Shear Stress in Diabetic Hyperlipidemic Juvenile Swine

Introduction: Low endothelial shear stress (ESS) activates pro-inflammatory pathways and is a powerful instigator of atherogenesis. Angiotensin receptor blockers and statins have been associated with anti-inflammatory actions in advanced plaques. However, their effect on the earliest pathobiologic manifestations of atherosclerosis has not been studied. We tested the hypothesis that valsartan (V) or V plus simvastatin (V/S) exerts an early vasculoprotective effect in coronary regions exposed to low ESS in a porcine model of human-like atherosclerosis. Methods: Twelve diabetic-hyperlipidemic swine (age: 3 mo) were grouped into controls (n=4), and those treated with V (320 mg; n=4) or V/S (320/40 mg; n=4). 3D reconstruction of coronary arteries by angiography and intravascular ultrasound was performed in vivo at 4 (baseline) and 8 (follow-up) wks post-induction. Baseline local ESS was calculated by computational fluid dynamics and 3 mm segments with low (≤1.2 Pa; n=46) or higher (&gt;1.2 Pa; n=66) ESS were identified. Coronary arteries were harvested at follow-up. qRT-PCR was used for assessing the expression of intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1), LDL receptor and lipoprotein-associated phospholipase-A 2 (LpPLA 2 ). Results: The upregulation of ICAM-1, MCP-1, LDL receptor (p&lt;0.05) and LpPLA 2 (p&lt;0.1) expression in low ESS segments was inhibited in the V and V/S groups compared to controls (Figure). Conclusion: V and V/S attenuate the proatherogenic effects of low ESS within only 8 wks. These results suggest a drug-induced mechanism of regional atheroprotection early in the natural history of coronary artery disease.

In Vivo 3D Distribution of Lipid-Core Plaque in Human Coronary Artery as Assessed by Fusion of Near Infrared Spectroscopy–Intravascular Ultrasound and Multislice Computed Tomography Scan

There is ample evidence that the development of acute coronary syndrome is linked to the presence of lipid-core, necrotic plaque. However, there is little information on the natural history of lipid-core plaques in humans. A close link between structural changes of atherosclerotic plaques over time to the local shear stress conditions in the arterial system has been reported.1 Although low shear stress is recognized for its proatherogenic impact on the endothelium,1 its role in plaque composition, destabilization, and rupture is less clear. The current paradigm postulates that low shear stress is a necessary condition for plaque accumulation. However, once lumen narrowing occurs because of plaque, local shear stress increases.2 We describe an approach that allows studying the interaction of lipid-core plaque accumulation and local shear stress in a correct anatomic 3D reconstruction of coronary arteries in living patients. A 61-year-old man with a history of myocardial infarction and stenting of the right coronary …

Integration of 3D reconstruction in the SELection criteria for Excessive Crossing Times for Magnetically Supported Percutaneous Coronary Intervention. SELECT-MP

To develop a clinical prediction rule based on 3D reconstruction of coronary arteries that would prospectively identify lesions that are difficult to cross and could benefit from magnetic navigation. The coronary anatomy of a cohort of 120 lesions that had undergone percutaneous coronary intervention (derivation set) was analysed using 3D reconstruction for vessel and lesion characteristics. The crossing time was the total clock time to reach a satisfactory distal position after leaving the guiding catheter. Multivariable logistic regression and linear shrinkage with bootstrapping were used to develop a clinical prediction rule that dichotomised cases into easy or difficult (prolonged crossing time). A value of 6 was the best cut-off value. This clinical prediction rule was applied to a second independent cohort of patients (validation set) where crossing time was measured. The bootstrapped c-statistic of the model was 0.82 indicating excellent discrimination. 3D reconstruction helped to develop a simple, accurate clinical prediction rule to identify difficult cases for conventional wires and in whom magnetic navigation may be preferable.

Optimal 3D reconstruction of coronary arteries for 3D clinical assessment

A novel method is presented for 3D reconstruction of the coronary arteries. The algorithm refines the point correspondences between the arteries visible in a pair of monoplane X-ray fluoroscopy images acquired at different incidences. Traditional computer vision techniques use the RANSAC methods to discard outliers in a list of corresponding points. However, as these methods work for rigid motion primarily, we introduce a curvature constraint that relates the 2D and 3D Frenet information of the coronary artery centerlines. This constraint takes into account non-rigid movement of the arteries and also serves as a refinement tool to discard potential outlier points. Results show that for synthetic experiments with left–right anterior oblique (LAO/RAO) and posterior–left lateral (PA/LAT) viewing angles, the average 3D RMS errors are respectively 3.1 mm and 1.9 mm for the RANSAC method, and decrease to 2.8 mm and 1.1 mm by using our curvature constraint methodology. Similarly, clinical validation is performed on two datasets and the average 2D retroprojection errors are 3.34 pixels and 2.24 pixels, respectively.