Medical ultrasound image reconstruction using distributed compressive sampling

International audienceThis paper investigates ultrasound (US) radiofrequency (RF) signal recovery using the distributed compressed sampling framework. The “correlation” between the RF signals forming a RF image is exploited by assuming that they have the same sparse support in the 1D Fourier transform, with different coefficient values. The method is evaluated using an experimental US image. The results obtained are shown to improve a previously proposed recovery method, where the correlation between RF signals was taken into account by assuming the 2D Fourier transform of the RF image sparse

A sparse reconstruction framework for Fourier-based plane wave imaging

International audienceUltrafast imaging based on plane-wave (PW) insonification is an active area of research due to its capability of reaching high frame rates. Among PW imaging methods, Fourier-based approaches have demonstrated to be competitive compared with traditional delay and sum methods. Motivated by the success of compressed sensing techniques in other Fourier imaging modalities, like magnetic resonance imaging, we propose a new sparse regularization framework to reconstruct high-quality ultrasound (US) images. The framework takes advantage of both the ability to formulate the imaging inverse problem in the Fourier domain and the sparsity of US images in a sparsifying domain. We show, by means of simulations, in vitro and in vivo data, that the proposed framework significantly reduces image artifacts, i.e., measurement noise and sidelobes, compared with classical methods, leading to an increase of the image quality

OntoVIP: An ontology for the annotation of object models used for medical image simulation.

International audienceThis paper describes the creation of a comprehensive conceptualization of object models used in medical image simulation, suitable for major imaging modalities and simulators. The goal is to create an application ontology that can be used to annotate the models in a repository integrated in the Virtual Imaging Platform (VIP), to facilitate their sharing and reuse. Annotations make the anatomical, physiological and pathophysiological content of the object models explicit. In such an interdisciplinary context we chose to rely on a common integration framework provided by a foundational ontology, that facilitates the consistent integration of the various modules extracted from several existing ontologies, i.e. FMA, PATO, MPATH, RadLex and ChEBI. Emphasis is put on methodology for achieving this extraction and integration. The most salient aspects of the ontology are presented, especially the organization in model layers, as well as its use to browse and query the model repository

A virtual imaging platform for multi-modality medical image simulation.

International audienceThis paper presents the Virtual Imaging Platform (VIP), a platform accessible at http://vip.creatis.insa-lyon.fr to facilitate the sharing of object models and medical image simulators, and to provide access to distributed computing and storage resources. A complete overview is presented, describing the ontologies designed to share models in a common repository, the workflow template used to integrate simulators, and the tools and strategies used to exploit computing and storage resources. Simulation results obtained in four image modalities and with different models show that VIP is versatile and robust enough to support large simulations. The platform currently has 200 registered users who consumed 33 years of CPU time in 2011

Traitement et analyse d'images cardiaques: Traité IC2 Série Information et Science du vivant

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Multi-modality Cardiac Imaging: Processing and Analysis

International audienceThe imaging of moving organs such as the heart, in particular, is a real challenge because of its movement. This book presents current and emerging methods developed for the acquisition of images of moving organs in the five main medical imaging modalities: conventional X-rays, computed tomography (CT), magnetic resonance imaging (MRI), nuclear imaging and ultrasound. The availability of dynamic image sequences allows for the qualitative and quantitative assessment of an organ’s dynamics, which is often linked to pathologies

Caractérisation fonctionnelle d'un heptapeptide cyclique inhibiteur d'activités b-lactamases et de protéines liant la pénicilline

A partir d'une enzyme, la b-Iactamase, nous avons généré un anticorps antiidiotypique à activité b-Iactamase que nous avons nommé 9G4H9. En comparant les résidus essentiels à l'activité catalytique de la b-Iactamase, nous avons proposé un modèle de site actif pour l'anticorps 9G4H9 dans lequel nous avons identifié les résidus arginine 24, sérine 26, lysine 27, sérine 28 et acide glutamique en position 98 susceptible d'être impliqués dans l'activité catalytique. Nous avons montré l'implication de tous les résidus identifiés dans l'activité catalytique hormis le résidu lysine en position 27. L'anticorps 9G4H9 a servi de cible pour la sélection d'un peptide inhibiteur par phage-display, nommé Pep90, d'activités b-Iactamases et d'activités parentes. Au cours de cette étude, nous avons caractérisé les modalités d'interaction de Pep90 respectivement avec l'anticorps catalytique 9G4H9, le scFv 9G4H9, différentes classes de b-Iactamases et DD-peptidases.9G4H9, a catalytic antibody displaying b-lactamase-Iike activity, has been elicited by the anti-idiotypic approach using b-Iactamase as first antigen. We proposed an active site model for antibody 9G4H9 in which we find residues arginine 24, serine 26, lysine 27, serine 28 and glutamic acid 98 that could be involved in b-Iactamase activity. We showed that ail the residues are involved in catalysis except residue lysine 27. ln the second part of the work, antibody 9G4H9 was used as target to screen b-Iactamase activity inhibitor among cyclic heptapeptide bank displayed on bacteriophage M13. One of the phage-displayed peptide (pep90) issued from the selection procedures was shown to be a competitive inhibitor of the b-Iactamase activity of the anti-idiotypic antibody, with a Ki = 38uM. We showed that Pep90 interact with several class of penicillin-binding protein, thus opening routes to the design of antibiotic-like molecules.COMPIEGNE-BU (601592101) / SudocSudocFranceF

Simultaneous coded plane wave imaging in ultrasound: problem formulation and constraints

International audienceIn this paper, we propose a new emission strategy in the context of plane wave imaging. Plane wave imaging indeed implies compounding in order to preserve a good image quality. Such compounding is usually obtained using multiple, successive emissions, which in turn yields a decrease of the frame rate. As opposed to this approach, our method is based on the simultaneous emission of several coded plane waves. This allows the reconstruction of all the images corresponding to the different plane waves, by using an inverse problem approach. The proposed method is closely related to channel estimation in telecommunications, and coded excitation in synthetic aperture ultrasound imaging. In this paper, we thus extend these lines of work to the case of ultrasound plane wave imaging and evaluate the obtained performance from various numerical simulations