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Deformable models and graph cuts are two standard image segmentation techniques. Combining some of their benefits, we introduce a new segmentation system for (semi-) automatic delineation of epicardium and endocardium of Left Ventricle of the heart in Magnetic Resonance Images (MRI). Specifically, a temporal information among consecutive phases is exploited via a coupling between deformable models...
We present a novel method for cardiac respiratory motion estimation in image-guided interventions. The technique combines a preprocedure affine motion model and intra-procedure real-time images to estimate and correct for the respiratory motion of the heart. As well as making motion estimates, the model is able to quantify the uncertainty in these estimates. This uncertainty is resolved using a Bayesian...
An accurate scar characterization plays an essential role for the treatment of ventricular tachycardia in patients with ischemic cardiomyopathy. Cardiac ablation based on electrical information is a widely used procedure to fix ventricular tachycardia. However, intra-operative scar characterization may be improved using mechanical information together with the electrical data. We propose in this paper...
Experimental rodent models of induced ischemic injury have been extensively used in biomedical research to study molecular, cellular and histological alterations following myocar-dial infarction. These models are increasingly employed to assess the potential of newly developed therapies for functional restoration of the damaged heart. Such studies are based on myocardial infarction induction followed...
To reduce noise within a tag line, unsharpen tag edges in the spatial domain, and amplify the tag-to-background contrast, a 3D energy minimization framework for the enhancement of tagged Cardiac Magnetic Resonance (CMR) images, that is based on first- and second-order learned visual appearance models, is proposed. The first-order appearance modeling uses an adaptive Linear Combination of Discrete...
A level set-based method for tracking the endocardium from 3D ultrasound images is presented. The tracking process is initialized by a manual delineation and performed automatically. The method does not use a shape prior model, removing the requirement of acquiring large sets of training data, and providing adaptivity for abnormal cases. At each image frame, the edge strength is estimated and locations...
Real-time MRI emerges as a feasible modality for guiding interventions and surgeries on the beating heart. One challenge is the path planning task for intra-cardiac procedures, which requires tracking the inner contour of the left endocardium on the beating heart. We propose a bottom-up approach to solve this tracking problem. On the bottom level, a coarse contour is generated based on a collaborative...
A new framework for accurate registration of the segmented left ventricle (LV) on cardiac first-pass magnetic resonance imaging (FP-MRI) to precisely analyze the myocardial transit of contrast agent, especially in the ischemically damaged heart, is proposed. Due to the continuous physiological motion of the heart that causes the LV wall to change shape significantly, within the same scan, at the same...
We introduce a patient-specific model for coronary circulation, by combining anatomical, hemodynamic and functional information from medical images and other clinical observations. The main components of the coupled model are: a lumped heart model, a reduced-order model for hemodynamics in the arterial vessel tree (both healthy and stenosed), and a physiological model for the microvascular bed. The...
Coarctation of the aorta (CoA), is an obstruction of the aortic arch present in 5–8% of congenital heart diseases. For children older than a year, CoA is increasingly treated by aortic stenting instead of surgical repair. In pediatric cardiology, CMR is accepted as the standard non-invasive imaging modality to assess the aortic arch in it's entire spatial context [1]. Interpreting such 3D datasets...
Pulmonary hypertension is a common cause of death among patients with sickle cell disease. This retrospective study investigates the use of pulmonary vein analysis to diagnose pulmonary hypertension non-invasively with CT-Angiography images. Ten images from patients with pulmonary hypertension were matched with controls. An adaptive fast marching approach is applied in order to segment the left atrium...
The dynamical structure of electrical recordings from the heart or torso surface is a valuable source of information about cardiac physiological behavior. In this paper, we use an existing data-driven technique for manifold identification to reveal electrophysiologically significant changes in the underlying dynamical structure of these signals. Our results suggest that this analysis tool characterizes...
The use of ultrasound imaging for image guidance of cardiac procedures is limited by the small field of view of the ultrasound volume. A larger view can be created by image-based registration of partially overlapping volumes, but automatic registration often fails unless the volume alignment is initialised close to the volumes' correct alignment. In this paper, we use X-ray images to track a trans-esophageal...
Catheter tracking has become more important in recent interventional applications for atrial fibrillation (AF) ablation procedures. It can provide real-time guidance for the physicians and be used for motion compensation by overlaying a 3D left atrium model on live 2D fluoroscopic images. To achieve that, this paper has two main contributions. We first propose a new approach to generate tracking hypotheses...
An atlas in the context of atlas-based segmentation refers to a pre-selected image with labelled anatomical regions of interest. Atlas-based segmentation is the propagation of these labels to a novel image after both images have been registered. The goal of an atlas is to be representative of an anatomical category, but in practice there exists variability in human anatomy. One solution to maintain...
We have developed techniques to automatically generate personalised biomechanical models of patients' hearts based on 3D cardiac images. We demonstrate this approach using multi-slice computed tomography images. Unsupervised segmentation was performed using non-rigid image registration with a segmented image. A finite element model was automatically fitted to the segmented data of the left ventricle...
Clinical translation of computational models of the heart has been hampered by the absence of complete and rigorous technical and clinical validation, as well as benchmarking of the developed tools. To address this issue, a dataset containing the cardiac anatomy and fibre orientations from magnetic resonance images (MRI), as well as epicardial transmembrane potentials from optical mapping acquired...
Personalization of cardiac functions and properties from subject-specific noninvasive clinical observations has been an active area with increasing clinical significance. The personalized cardiac information can quantitatively reflect the pathophysiology of an individual heart and further be used to assist heart diagnosis and treatment planning. Due to the electromechanically integrated nature of...
Cardiac therapies aim to correct pathological blood flow. Patient-specific therapy planning is challenging due to the large variability in disease cause, location and severity. A predictive framework is therefore needed to assess the optimal treatment for a patient in terms of maximizing effectiveness (blood flow velocity, vorticity, cardiac output, etc.) and minimizing the risk of complications....
Cardiac electrophysiology procedures are routinely used to treat patients with rhythm disorders. The success rates of ablation procedures and cardiac resynchronization therapy are still sub-optimal. Recent advances in medical imaging, image processing and cardiac biophysical modeling have the potential to improve patient outcome. This manuscript provides an overview of how these advances have been...
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