CREASEG: A free software for the evaluation of image segmentation algorithms based on level-set

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Fast and fully automatic 3D echocardiographic segmentation using B-spline explicit active surfaces

International audienceWe have recently introduced a novel framework to efficiently deal with 3D segmentation of challenging inhomogeneous data in real-time. However, the existing framework still relied on manual initialization, which prevented taking full advantage of the computational speed of the method. In the present manuscript we propose an automatic initialization scheme adapted to 3D echocardiographic data and we couple it with the existing segmentation framework. Moreover, a novel segmentation functional, which explicitly takes the darker appearance of the blood into account, is also proposed in the present manuscript. We show that fully automatic segmentation of the left ventricle using the proposed method provides an efficient, fast and accurate solution for quantification of the main cardiac indices used in routine clinical practice

Towards real-time 3D region-based segmentation: B-spline explicit active surfaces

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Using a geometric formulation of annular-like shape priors for constraining variational level-sets

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Neuromuscular Fiber Segmentation Through Particle Filtering and Discrete Optimization

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Towards online real-time strain estimation in volumetric us data: Feasibility study and initial clinical validation

International audienceStrain-based functional indices have been shown to provide superior performance in assessing global cardiac function when compared with classical volume-based metrics, such as ejection fraction. As in clinical practice global strain is typically used as an index of overall cardiac performance, local tracking algorithms, which are typically computationally intensive, could be substituted by more global approaches. We therefore propose to take advantage of a fast tracking method which uses an optical-flow algorithm on an anatomical ROI to estimate the global cardiac (affine) motion between consecutive frames. The proposed approach was tested in 19 RT3DE exams by assessing the global area strain (GAS), which combines both longitudinal and circumferential deformation. The agreement between the automatic tracking results and the reference show moderate correlation (r=0.698), while Bland-Altman analysis ([μ±1.96σ]=6.0±9.29%) revealed a significant bias, although having competitive limits of agreement when compared with the inter-observer variability ([μ±1.96σ]=0.85±9.52%). The proposed approach takes less than 1 second to perform the tracking between two subsequent frames, in a MATLAB implementation. These preliminary results point towards the feasibility of online estimation of global deformation parameters without any user intervention and near real-time

A level-set approach for tracking objects in image sequences using a level conservation constraint: Application to cardiac sequences

International audienceTracking of moving objects in an image sequence is an important task in many application (e.g. medical imaging, robotics). However, this task is usually difficult due to inherent problems that could happen in sequences (i.e. possible occlusion of the object, large interframe motion). In this paper, we describe a new approach to integrate a priori motion information into a level-set-based active contour approach. Specifically, we introduce a new constraint that enforces the conservation of the levels of the implicit function along the image sequence. This constraint is formulated as a motion prior energy and is used in a tracking algorithm. The method is validated quantitatively on a clinical application based on 10 echocar-diographic and 5 cine-MRI sequences (≈ 700 images)

Real-time region-based segmentation of 3D inhomogeneous objects in medical images

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Towards real-time 3D region-based segmentation: B-spline explicit active surfaces

International audienc