Tesi sul tema "Imagerie médicale – Évaluation"
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Mihalcea, Adela Cecilia. "Évaluation du foie restant post hépactectomie partielle par les examens d'Imagerie médicale". Lyon 1, 2004. http://www.theses.fr/2004LYO10104.
Bouakaz, Ayache. "Produits de contraste ultrasonore : évaluation acoustique in vitro et application". Lyon, INSA, 1996. http://www.theses.fr/1996ISAL0058.
It's usually more difficult for a radiologist to interpret ultrasonic images than other records issued from other imaging modalities. Indeed, the ultrasonic record has no familiar landmarks for the uninitiated observer. As for other imaging techniques, the use of contrast agents could be considered. Typically, contrast ultrasound involves the injection of echo-producing microbubbles into the bloodstream to enhance the ultrasound echogenicity of a certain structure in the body. In the first part of this study, we proposed a theoretical approach for acoustic characterization of ultrasound contrast agents. Simultaneously, an experimental procedure was developed to quantify the ultrasonic properties of contrast agents in vitro. This was carried out by determining their acoustic parameters. The backscatter coefficient (BC), attenuation coefficient and scattering to attenuation ratio (STAR) were defined to quantify the ultrasonic effectiveness of the contrast agent. The experimental conditions correspond to the clinical reality. The experimental determination of ultrasonic properties is important for an appropriate use of the contrast agent. Afterwards, a method is presented and used to determine the acoustic contribution of a contrast agent to the image enhancement. Optimal values of the acoustic properties necessary to get a visible enhancement of the image are deduced. At last, we propose a newer clinical application using contrast agent. This has been done in intravascular echography and the contrast has been proved useful for this application
Folliot, Véronique. "Synthèse et évaluation de molécules et macromolécules chelatantes en vue de leur utilisation en imagerie médicale". Le Mans, 1989. http://www.theses.fr/1989LEMA1005.
Bergeron, Mélanie. "Évaluation des performances du scanner LabPET". Mémoire, Université de Sherbrooke, 2009. http://savoirs.usherbrooke.ca/handle/11143/4008.
Bernardin, Aude. "Méthodes biocompatibles de fonctionnalisation de substrats et surfaces : évaluation par imagerie de fluorescence". Paris 11, 2009. http://www.theses.fr/2009PA112255.
This work describes the development of biocompatible functionalisation methods of wide interest in the field of biomedical applications. A new water-compatible coupling method between nitrones and strained-cycloalkynes is here developed, by analogy with the [3+2] cycloaddition between azides and strained-cycloalkynes described in the literature. The efficiency of the coupling is evaluated by fluorescence imaging. Two fluorescent probes bearing cyclooctyne groups are synthesized, an organic dye-based probe and a quantum dotbased probe. Contrary to Cu(I)-catalyzed click chemistry, the developped methodology enables quantum dots’ functionalization while maintaining their high fluorescence quantum yield. Glass slides have also been coated with azides or nitrones, surfaces on which can be subsequently grafted cyclooctyne-probes. Fluorescent labelling of cell membrane’s sialic acids after metabolic incorporation of modified mannosamines has also been carried out in vitro to confirm the potential interest of strained-alkyne chemistry in biological conditions
Baudin, Olivier. "Schéma de compression adaptative d’image : Modélisation paramétrique et classification, quantification et codage, évaluation. Application en imagerie médicale". Lyon, INSA, 1996. http://www.theses.fr/1996ISAL0024.
This work concerns the study and the realization of a medical (static) image compression algorithm. The method integrates a learning phase during which image data bases of given medical modalities are analyzed in order to adjust and adapt the compression scheme to the local caracteristics of the images. The quality of the reconstructed images is evaluated using an ROC protocol
Hajjaj, Bouchra. "Conception, synthèse et évaluation biologique d’antagonistes de la bombésine pour la visualisation de cancers par imagerie médicale". Thesis, Montpellier 1, 2013. http://www.theses.fr/2013MON13517.
The abundant expression of the GRP receptor in many frequently occurring cancers that inflict humans provides the opportunity to use radiolabeled bombesin analogs for their diagnosis and treatment. This postgraduate work is dedicated to the design, synthesis and biological evaluation of new radiopharmaceuticals. These are made up of a GRP receptor antagonist, a spacer and the cyclic metal chelating agent DOTA. We first determined the spacer length which has optimal biological properties. Moving forward from this study, different radio-ligands containing new bombesin antagonists have been synthesized and biologically evaluated. Those antagonists are based on compound JMV 594, a powerful bombesin antagonist synthesized in our laboratory. Besides modifications of this peptide also dimers have been made to obtain more stable bombesin antagonist with more affinity to the GRP receptor
Hungr, Nikolai. "Conception et évaluation de systèmes robotiques de ponction d'aguilles percutanées sous contrôle d'imagerie médicale". Phd thesis, Université de Grenoble, 2014. http://tel.archives-ouvertes.fr/tel-00997017.
Bondiau, Pierre-Yves. "Mise en oeuvre et évaluation d'outils de fusion d'image en radiothérapie". Nice, 2004. http://www.theses.fr/2004NICE4114.
Cancer is a major problem of public health. Treatment can be done in a general or loco-regional way, in which case medical images are important as they specify the localization of the tumour. The objective of the radiotherapy is to deliver a curative dose of radiation in the target volume while sparing the organs at risks (OAR). The determination of the accurate localization of the targets volume as well as OAF makes it possible to define the ballistics of irradiation beams. After the description of the principles of radiotherapy and cancers treatment, we specify the clinical stakes of ocular, cerebral and prostatic tumours. We review the state of the art image matching algorithms, with a didactic purpose for the medical community. The results of image matching techniques are presented in the framework of cerebral and prostatic radiotherapy planning in order to determine the types of applicable method in oncology. Then, we present the prospects for these methods with respect to the anatomical localization and automatic segmentation. Applications of automatic segmentation and the evaluation of the results in the framework of brain tumour are described after a review of the various segmentation methods according to anatomical localizations. An original application is the digital simulation of the virtual tumoral growth and the comparison with the real growth of a cerebral tumour presented by a patient. We conclude with the future developments possible of the tools for image processing in radiotherapy as well as the tracks of research to be explored in oncology
Urbano, Rodriguez Luis Alberto. "Contribution à la compression d'images par transformée en cosinus discrète en imagerie médicale, et évaluation sur une base d'images multi-modalités". Tours, 1991. http://www.theses.fr/1991TOUR3307.
Mouhamed, Souad. "Dévelopement et évaluation d'un logiciel d'imagerie médicale, implante sur une station de travail, pour une utilisation dans un service de pneumologie". Lyon, INSA, 1994. http://www.theses.fr/1994ISAL0090.
In a hospital, the tasks of information retrieval and image manipulations are generally manual. Physicians spend an important part of their work to search and handle of medical information. The integration and the adaptation of a workstation to different tasks of the clinician appear as a good. Solution. The automatisation of these tasks open new perspectives to physicians such as image processing. This study is devoted to the design and the realization of a software allowing interactive visualization and processing of multi modalities medical images. This software is implemented on a workstation which is intended to be integrated in a PACS. Ours goals in the conception have primarily been to respect the methodology and the needs of the clinicians. Thus, the software provides functionalities for selection, visualization, and processing the images in order to help the clinician to establish his diagnosis. We used a functional decomposition method which lead to a division of the software in modules. This modules are defined from the decomposition of the working method of the clinician, and are independent from each others. The user interface which constitutes a privileged connection between the user and the system has been developed with particular attention. Due to his conviviality and its ergonomy, the software is us able by non-computer-oriented users. The evaluation of the software by medical experts on the hospital site has confirmed the call of the physicians for this type of tool, and has emphasized their motivation for working with such a software
Martin, Chantal. "Conception d'une sonde anti-diffraction et évaluation d'algorithmes en vue de la mesure locale de l'atténuation dans les tissus biologiques". Lyon 1, 1988. http://www.theses.fr/1988LYO1T151.
Colliot, Olivier. "Représentation, évaluation et utilisation de relations spatiales pour l'interprétation d'images : application à la reconnaissance de structures anatomiques en imagerie médicale". Phd thesis, Télécom ParisTech, 2003. http://tel.archives-ouvertes.fr/tel-00005764.
constituent un élément essentiel des descriptions d'agencement spatial entre les objets d'une scène et sont donc utiles à un grand nombre de tâches d'interprétation d'images. La reconnaissance de structures cérébrales constitue notre cadre d'application. Le cerveau est en effet une scène structurée dans
laquelle les objets partagent une grand nombre de relations
spatiales pertinentes.
Notre travail de thèse est articulé autour des questions suivantes.
Comment représenter des relations spatiales ? Comment les utiliser pour
formaliser la description d'une scène, en l'occurrence la description de
structures neuroanatomiques ? Comment les utiliser à des fins de segmentation
d'images et de reconnaissance de formes, en particulier dans le cadre des structures cérébrales ?
Dans un premier temps, nous nous intéressons à un type de relation particulier :
les symétries planes, qui sont importantes dans le cadre de l'imagerie
cérébrale et ont été l'objet de moins d'attention que d'autres types de relations.
Nous proposons une méthode pour quantifier le degré de
symétrie dans les objets flous et les images via une mesure de symétrie ainsi qu'un algorithme pour
localiser le plan de symétrie d'un objet donné. L'application de cette méthode au plan de symétrie du cerveau est précise et robuste comme l'a montré l'évaluation menée sur des images synthétiques et réelles.
Puis nous montrons comment la description des structures cérébrales peut se faire
à l'aide d'un ensemble de relations spatiales et comment une telle description
peut être formalisée par un graphe hiérarchique synthétique. Cette description est
comparée avec celle obtenue à partir d'un atlas iconique, grâce à une structure appelée graphe hiérarchique exemple.
Enfin, les deux dernières parties traitent de l'utilisation des relations spatiales
en segmentation d'images. Une méthode pour intégrer de telles connaissances à un
modèle déformable via la construction d'une force externe est proposée. Elle se distingue nettement des autres approches disponibles puisque les relations sont directement introduites pour la recherche des contours des objets. Nous
présentons ensuite une procédure complète de segmentation de structures cérébrales internes fondée
sur la description précédente et sur un modèle déformable. Les premiers résultats obtenus, évalués visuellement, sont prometteurs.
Shi, Yu. "Mise en oeuvre et évaluation d'un dispositif d'imagerie d'impédance bioélectrique". Toulouse, INPT, 1992. http://www.theses.fr/1992INPT068H.
Ménard, Laurent. "Étude, développement et évaluation clinique d'un imageur gamma per-operatoire". Versailles-St Quentin en Yvelines, 1999. http://www.theses.fr/1999VERS0002.
Souplet, Jean-Christophe. "Évaluation de l'atrophie et de la charge lésionnelle sur des séquences IRM de patients atteints de sclérose en plaques". Phd thesis, Université de Nice Sophia-Antipolis, 2009. http://tel.archives-ouvertes.fr/tel-00635295.
Renaudin, Christian. "Qualité image et évaluation de la sténose artérielle en angiographie numérique à l'aide du scanner X 3D morphomètre". Lyon 1, 1993. http://www.theses.fr/1993LYO1T208.
Zhang-Ge, Lu. "Modèles numériques pour l'évaluation objective de la qualité d'images médicales". Angers, 2012. http://tel.archives-ouvertes.fr/tel-00995416.
Medical image quality assessment is critical for comparing and optimizing medical imaging system. In the frame of task-based approach, numerical observers proposed for the objective medical image quality assessment have several limitations: e. G. For the multi-signal localization, most need a priori knowledge of signal parameters; multi-slice MOs narrow the task down to the detection of one symmetrical signal at the image centre. In this thesis, we propose novel numerical observers: the CJO for the detection of one parametric signal with random amplitude, orientation and size on single-slice; the PCJO and the msPCJO for the detection-localization of multiple parametric signals with random amplitude, orientation, size and location on single-slice and multi-slice, respectively. Two observer studies were designed and implemented for their validation on MR images with MS lesions, and the JAFROC FOM results indicate that they are promising for predicting radiologists' task performance, ultimately for evaluating medical imaging systems
Fresneau, Nathalie. "Synthèse d'hétérocycles tricycliques à noyau diazinique et leur évaluation comme ligands des récepteurs sérotoninergiques 5-HT4 pour un traitement de la maladie d'Alzheimer". Rouen, 2013. http://www.theses.fr/2013ROUES005.
Cherifi, Daikha. "Amélioration et évaluation de la qualité des images". Thesis, Paris 13, 2014. http://www.theses.fr/2014PA132053.
The aim of this thesis is to propose new methods for image enhancement based on oriented and multi-scale transforms using some perceptual criteria. The first part of the thesis is devoted to the development of a simple and efficient contrast enhancement method inspired from the human visual system. This method is evaluated on a set of natural color and monochrome images. The obtained results are evaluated subjectively and by using objective measures based on energy spectrum analysis and perceptual criteria. The enhancement technique is also extended to some medical images, such as mammography and endoscopy images. A special contrast enhancement method adapted to mammography is then proposed. It is based on a segmentation process using a priori information on the mammography images. The last part of the thesis is devoted to image enhancement evaluation. A critical literature survey of image enhancement evaluation methods is provided. The evaluation method proposed in this thesis is based on the radial and angular analysis of the Fourier powerspectrum. Another perceptual approach is proposed to evaluate the output. This method is based on the analysis of the visibility map computed by using a pyramidal contrast. The evaluation is performed on some samples taken from two databases. Both subjective and objective evaluations demonstrate the efficiency of the proposed image enhancement methods
Eickenberg, Michael. "Évaluation de modèles computationnels de la vision humaine en imagerie par résonance magnétique fonctionnelle". Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112206/document.
Blood-oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) makes it possible to measure brain activity through blood flow to areas with metabolically active neurons. In this thesis we use these measurements to evaluate the capacity of biologically inspired models of vision coming from computer vision to represent image content in a similar way as the human brain. The main vision models used are convolutional networks.Deep neural networks have made unprecedented progress in many fields in recent years. Even strongholds of biological systems such as scene analysis and object detection have been addressed with enormous success. A body of prior work has been able to establish firm links between the first and last layers of deep convolutional nets and brain regions: The first layer and V1 essentially perform edge detection and the last layer as well as inferotemporal cortex permit a linear read-out of object category. In this work we have generalized this correspondence to all intermediate layers of a convolutional net. We found that each layer of a convnet maps to a stage of processing along the ventral stream, following the hierarchy of biological processing: Along the ventral stream we observe a stage-by-stage increase in complexity. Between edge detection and object detection, for the first time we are given a toolbox to study the intermediate processing steps.A preliminary result to this was obtained by studying the response of the visual areas to presentation of visual textures and analysing it using convolutional scattering networks.The other global aspect of this thesis is “decoding” models: In the preceding part, we predicted brain activity from the stimulus presented (this is called “encoding”). Predicting a stimulus from brain activity is the inverse inference mechanism and can be used as an omnibus test for presence of this information in brain signal. Most often generalized linear models such as linear or logistic regression or SVMs are used for this task, giving access to a coefficient vector the same size as a brain sample, which can thus be visualized as a brain map. However, interpretation of these maps is difficult, because the underlying linear system is either ill-defined and ill-conditioned or non-adequately regularized, resulting in non-informative maps. Supposing a sparse and spatially contiguous organization of coefficient maps, we build on the convex penalty consisting of the sum of total variation (TV) seminorm and L1 norm (“TV+L1”) to develop a penalty grouping an activation term with a spatial derivative. This penalty sets most coefficients to zero but permits free smooth variations in active zones, as opposed to TV+L1 which creates flat active zones. This method improves interpretability of brain maps obtained through cross-validation to determine the best hyperparameter.In the context of encoding and decoding models, we also work on improving data preprocessing in order to obtain the best performance. We study the impulse response of the BOLD signal: the hemodynamic response function. To generate activation maps, instead of using a classical linear model with fixed canonical response function, we use a bilinear model with spatially variable hemodynamic response (but fixed across events). We propose an efficient optimization algorithm and show a gain in predictive capacity for encoding and decoding models on different datasets
Jouclas, Rémy. "Synthèse et évaluation d'agents de contraste destinés à la détection multimodale d'une activité enzymatique". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS493.
Medical imaging has allowed Mankind to reach a good knowledge in human anatomy, body operation and to diagnose pathologies earlier and earlier, through minimally invasive techniques. Molecular imaging at the heart of this science enables the sight of biological processes standing in the operation of life for both exploratory, diagnostic, therapeutic and even theranostic means. As a wide part of metabolism is provided by enzymatic activity, its imbalance can mean pathological context. Thus, monitoring enzymatic activity through molecular imaging could become a new power weapon in medical arsenal. Among best adapted imaging techniques to this stake, Magnetic Resonance Imaging (MRI) permits to picture tissues and organs non-invasively, widely through contrast agent prescription. These molecules designed to sharpen acquired images quality can also be used for reaction with biological targets of interest, especially enzymes, thus binding those pictures with biological and physiological data. In the many pharmacological tools associated with MRI, lanthanides complexes have already proven efficiency in clinical imaging, and are likely to be detected through three complementary imaging modalities: T₁-MRI, paraCEST-MRI and optical imaging.Our team achieves the design of a tunable platform that can detect a wide range of enzymes. It is composed of a “trigger” that can be activated by a targeted enzyme, bound through a self-immolative linker to a “reporter” moiety that enables the probe to be detected. The latter is endowed with a lanthanide chelate that gives the probe magnetic and optical properties that can be monitored by T₁-MRI or paraCEST-MRI. In addition, a pyridine antenna enables lanthanide sensitization and luminescence, that can be detected by optical imaging. Upon enzymatic activation, self-immolation of the linker causes the release of the reporter moiety, and the modification of its magnetic and optical properties.Previous work in our team has achieved the synthesis of a probe following these concepts and aiming at β-galactosidase activity detection. However, enzyme-triggered self-immolation of the probe did not release the activated reporter moiety, due to the linker’s coordination to the lanthanide. This PhD project is thus intended to modify the chemical structure of this platform to enhance its activation kinetics, while keeping it detectable by MRI and optical imaging. To reach this goal, six novel analogues have been synthetized as models without trigger moiety to check the preservation of magnetic and optical properties while making synthesis easier and faster. Following probes’ magnetic and optical characterization, two structures were selected for the design of a probe aiming at β-galactosidase activity detection. The first one could enable trimodal detection of its activity, and the second one showed pH-dependency of T₁ and paraCEST effects. After synthesis, enzymatic tests allowed us to monitor enzyme activation kinetics for both probes by the previously scheduled imaging modalities
Mambo, Shadrack. "Optimisation et évaluation des performance en traitement d'image". Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1125/document.
D’Tech Thesis SummaryThe importance of medical imaging as a core component of several medical application and healthcare diagnosis cannot be over emphasised. Integration of useful data acquired from different images is vital for proper analysis of information contained in the images under observation. For the integration process to be successful, a procedure referred to as image registration is necessary.The purpose of image registration is to align two images in order to find a geometric transformation that brings one image into the best possible spatial correspondence with another image by optimising a registration criterion. The two images are known as the target image and the source image. Image registration methods consist of having the two images referenced with control points. This is followed by a registration transformation that relates the two images and a similarity metric function that aims to measure the qualitative value of closeness or degree of fitness between the target image and the source image. Finally, an optimiser which seeks an optimal transformation inside the defined solution search space is performed.This research presents an automated image registration algorithm for solving multimodal image registration on lung Computer Tomography (CT) scan pairs, where a comparison between regular step gradient descent optimisation technique and evolutionary optimisation was investigated. The aim of this research is to carry out optimisation and performance evaluation of image registration techniques in order to provide medical specialists with estimation on how accurate and robust the registration process is. Lung CT scan pairs are registered using mutual information as a similarity measure, affine transformation and linear interpolation. In order to minimise the cost function, an optimiser, which seeks the optimal transformation inside the defined search space is applied.Determination of a transformation model that depends on transformation parameters and identification of similarity metric based on voxel intensity were carried out. By fitting transformation to control points, three transformation models were compared. Affine transformation produced the best recovered image when compared to non-reflective similarity and projective transformations. The results of this research compares well with documented results from EMPIRE 10 Challenge research and conforms to both theoretical principles as well as practical applications.The contribution of this research is its potential to increase the scientific understanding of image registration of anatomical body organs. It lays a basis for further research in performance evaluation of registration techniques and validation of procedures to other types of algorithms and image registration application areas, such as remote sensing, satellite communication, biomedical engineering, robotics, geographical information systems and mapping, among others
Nguyen, Tan-Sy. "A smart system for processing and analyzing gastrointestinal abnormalities in wireless capsule endoscopy". Electronic Thesis or Diss., Paris 13, 2023. http://www.theses.fr/2023PA131052.
In this thesis, we address the challenges associated with the identification and diagnosis of pathological lesions in the gastrointestinal (GI) tract. Analyzing massive amounts of visual information obtained by Wireless Capsule Endsocopy (WCE) which is an excellent tool for visualizing and examining the GI tract (including the small intestine), poses a significant burden on clinicians, leading to an increased risk of misdiagnosis.In order to alleviate this issue, we develop an intelligent system capable of automatically detecting and identifying various GI disorders. However, the limited quality of acquired images due to distortions such as noise, blur, and uneven illumination poses a significant obstacle. Consequently, image pre-processing techniques play a crucial role in improving the quality of captured frames, thereby facilitating subsequent high-level tasks like abnormality detection and classification. In order to tackle the issues associated with limitations in image quality caused by the aforementioned distortions, novel learning-based algorithms have been proposed. More precisely, recent advancements in the realm of image restoration and enhancement techniques rely on learning-based approaches that necessitate pairs of distorted and reference images for training. However, a significant challenge arises in WCE which is an excellent tool for visualizing and diagnosing GI disorders, due to the absence of a dedicated dataset for evaluating image quality. To the best of our knowledge, there currently exists no specialized dataset designed explicitly for evaluating video quality in WCE. Therefore, in response to the need for an extensive video quality assessment dataset, we first introduce the "Quality-Oriented Database for Video Capsule Endoscopy" (QVCED).Subsequently, our findings show that assessing distortion severity significantly improves image enhancement effectiveness, especially in the case of uneven illumination. To this end, we propose a novel metric dedicated to the evaluation and quantification of uneven illumination in laparoscopic or WCE images, by extracting the image's background illuminance and considering the mapping effect of Histogram Equalization. Our metric outperforms some state-of-the-art No-Reference Image Quality Assessment (NR-IQA) methods, demonstrating its superiority and competitive performance compared to Full-Reference IQA (FR-IQA) methods.After conducting the assessment step, we proceed to develop an image quality enhancement method aimed at improving the overall quality of the images. This is achieved by leveraging the cross-attention algorithm, which establishes a comprehensive connection between the extracted distortion level and the degraded regions within the images. By employing this algorithm, we are able to precisely identify and target the specific areas in the images that have been affected by distortions. This allows an appropriate enhancement tailored to each degraded region, thereby effectively improving the image quality.Following the improvement of image quality, visual features are extracted and fed into a classifier to provide a diagnosis through classification. The challenge in the WCE domain is that a significant portion of the data remains unlabeled. To overcome this challenge, we have developed an efficient method based on self-supervised learning (SSL) approach to enhance the performance of classification. The proposed method, utilizing attention-based SSL, has successfully addressed the issue of limited labeled data commonly encountered in the existing literature
Griffon, Nicolas. "Modélisation, création et évaluation de ux de terminologies et de terminologies d'interface : application à la production d'examens complémentaires de biologie et d'imagerie médicale". Phd thesis, Université de Rouen, 2013. http://tel.archives-ouvertes.fr/tel-00877697.
Rene, Amandine. "Conception d'une méthodologie d'évaluation et de validation cliniques d'un dispositif médical logiciel d'aide au diagnostic en imagerie : application au suivi lésionnel en oncologie". Thesis, Montpellier 1, 2014. http://www.theses.fr/2014MON1T009.
Aided-diagnosis software in imaging are now integrated to radiological workflow but they are also key elements in medical research. Defined as medical devices, recent regulatory changes now impose clinical evaluations on manufacturers. The pharmaceutical industry benefits from a proven method in drug evaluation. Yet, transposition to medical devices is not fully effective and even more complex in the case of software. The aim of this thesis is to propose a clinical evaluation and validation methodology for these devices. The first part introduces the normative and regulatory framework as well as methodologies from various areas. The synthesis of these data allows the presentation of the first methodology item enabling the clinical evaluation of software performance. In order to further the analysis, the second part of the methodology is dedicated to evaluation/validation of software ergonomics, a sensitive issue in medical software. Finally, to restore these devices to their true place in health care, the last item proposes to highlight their impact in clinical practice and in patient management, through their implication in the search for new biomarkers in imaging. These various methods comply with and go beyond the regulatory framework in order to meet the expectations of all the stakeholders involved in the life cycle of aided-diagnosis software in imaging. To conclude, an example of its application is presented showing the impact of a dedicated software in the evaluation of oncology response in imaging
Benyahia, Nesrine. "Le droit de l'imagerie médicale et ses enjeux de santé publique : étude comparative France, Angleterre, Allemagne et Québec". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCB173.
Medical imaging is a care activity at the crossroads of all medical specialties. It has become a primary care activity at the heart of the diagnosis and treatment of many pathologies in oncology, neurology and cardiology, for instance. Its essential role in the care path of the patient is the result of the important development of the technologies, but also of the clinical indications. The framing of medical imaging in the French healthcare system remains nevertheless unclear and bordered by legal and economic constraints. This legal and economic uncertainty is an obstacle to the effective access to medical imaging technology for patients through, in particular, an exacerbated control of equipment installations and a disorganized acts pricing procedure. Furthermore, the lack of medico-economic evaluations delays the implementation of innovations and even creates risks to the safety and quality of the imaging tests performed
Gross, Dominique. "Conception et évaluation d'une sonde CMUT mixte dédiée à la thérapie ciblée à guidage ultrasonore". Thesis, Tours, 2015. http://www.theses.fr/2015TOUR3313/document.
Presented for the first time in 1994, capacitive micromachined ultrasonic transducers (CMUT) are a promising alternative to the piezoelectric technology for electroacoustic transduction. Particularly, their intrinsic design flexibility and miniaturization capability are strong advantages for the manufacturing of high-end Ultrasound-guided Focused Ultrasound (USgFUS) probes. The work presented in this Ph.D. dissertation is devoted to the f irst development of a USgFUS CMUT probe. After a general introduction of the CMUT technology and the context of this research project, the development is reported starting from the preliminary numerical studies to the most advanced characterizations of the fabricated device. The first results demonstrate the benefits of this technology for the targeted applications
Marache-Francisco, Simon. "Évaluation de la correction du mouvement respiratoire sur la détection des lésions en oncologie TEP". Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00770662.
Khalil, Toni. "Processus d’évaluation de la qualité de l’imagerie médicale et outils d’aide à la décision basée sur la connaissance". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0351.
The great progress that medical imaging has offered in the medical sector on the diagnostic level (Conventional Radiology, Computed Tomography, Nuclear Magnetic Resonance and Interventional Radiology) has pushed medicine to go through this area as the first choice. With an ever-increasing number of diagnostic images produced each year, as well as the recommendations of international organizations requiring low-dose irradiation resulting in enormous noise that can distort the diagnosis, Artificial Intelligence (AI) de-noising methods offer an opportunity to meet growing demand. In this thesis, we quantify the effect of AI-based de-noising on X-ray textural parameters with respect to a convolutional neural network.The study was based on the principle of characterizing the radiographic noise resulting from an X-ray of a water phantom and, generating this noise in a standard dose radiography aimed at producing artificially noisy images, and this in order to be able to feed a neural network by thousands of images to ensure its learning phase. After the learning phase, the testing phase and the inference, human chest X-rays were extracted from the archive to validate the de-noising on human X-rays in RGB and in “greyscale”. The study was done through a water phantom for ethical reasons in order to avoid irradiating people, avoiding voluntary and involuntary patient movements, and ensuring a study based on a homogeneous material (water) which constitutes the majority of the human body. This study is carried out on the one hand on 17 X-rays of a water phantom with different exposure doses to study the noise distribution on different gray scale values and, on the other hand on 25 X-rays divided into 5 groups of 5 images each taken with the same exposure dose without and with adjacent obstacles to study the gain effect of the flat panel detector chosen as the pre-processing means. The noise distribution was detected on two gray levels, i.e. 160 and 180 respectively, and showed a higher level of noise on the 160 level where the absorption of the X-ray beam is greater and, consequently, the quantum effect is most important. Noise scatter diagrams on these two levels have been shown. On the other hand, the presence of obstacles in the same image showed an absorption directly proportional to the number of obstacles next to the water phantom, which triggered a gain factor of the detector which, in its role produces nonlinear trace noise. Texture characteristics of AI-de-noised images compared to artificially noisy radiographs were compared with a peak signal-to-noise ratio (PSNR) coefficient. Features with increased PSNR values on RGB images and on greyscale images were considered to be consistent. A test to compare absolute values between AI-de-noised and artificially noisy images was performed. The results of the concordant features report were (38.05/30.06) -100 (26.58%) improvement in RGB versus (35.93/22.21) - 100 (61.77%) improvement in ‘greyscale'. In conclusion, applying AI-based de-noising on X-ray images retains most of the texture information of the image. AI-based de-noising in low-dose radiography is a very promising approach because it adapts de-noising, preserving information where it should
Benoit, Didier. "Conception, reconstruction et évaluation d'une géométrie de collimation multi-focale en tomographie d'émission monophotonique préclinique". Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00949951.
Gautier, Juliette. "Nanoparticules d'oxydes de fer PEGylées pour la délivrance de la doxorubicine : développement et évaluation de leur potentiel théragnostique". Thesis, Tours, 2013. http://www.theses.fr/2013TOUR3805/document.
PEGylated superparamagnetic iron oxide nanoparticles (SPIONs) were used as a platform to build theranostic nanovectors for the delivery of an anticancer drug, doxorubicin (DOX). The DOX loading on nanocarriers via a DOX-iron (II) complex was optimized. The complex dissociates at low pH, typical of intracellular compartments. Surface enhanced Raman scattering (SERS) confirmed that the nanovectors released DOX under free form. In vitro cytotoxicity due to DOX loaded on nanocarriers was performed on different breast cancer cells, and compared to that of DOX in solution. Internalization pathways of nanovectors were explored with transmission electron microscopy (TEM), and intracellular fate of DOX was monitored by confocal spectral imaging (CSI). To finish, a therapeutical protocol was performed on tumorized mice, in order to evaluate the efficacy of the nanoformulation on tumor reduction, the possibility of magnetic targeting, and the decrease of side effects induced by DOX
Denneval, Charline. "Design, synthèse et évaluation de contrastophores bimodaux pour l'imagerie par absorption à deux photons et par tomographie par émission de positons". Thesis, Rouen, INSA, 2014. http://www.theses.fr/2014ISAM0012/document.
The purpose of this subject has been the synthesis of a bimodal probe using TPA–PET techniques for a potential application in biological imaging.In this context, we have synthesized a new range of A–π –D fluorophores incorporating diazine (p-deficient heterocycle) as electron-withdrawing moiety, N,N-dimethylaniline as electron-donating part and fluorene as p-conjugated linker. In order to increase the conjugation along the scaffold, ethynyl and/or triazole bridges have been introduced on both sides of the fluorene. The UV/Vis and photoluminescence properties have been measured. Further to those results two-photon absorption cross-section of our fluorophores (dTPA) has been obtained. Following these promising results, hydrophilic compounds using PEG groups have been prepared and photoluminescence properties have been carried out. In order to use the boron center as a site for radiofluorination, the synthesis of "BODIPY-like" probes has been considered. A new series of pyrimidine and triazole ligand have been synthesized but the corresponding boron complexes haven’t been obtained
Jiang, Zhifan. "Évaluation des mobilités et modélisation géométrique du système pelvien féminin par analyse d’images médicales". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10003/document.
The better treatment of female pelvic mobility disorders has a social impact affecting particularly aged women. It is in this context that this thesis focuses on the development of methods in medical image analysis, for the evaluation of pelvic mobility and the geometric modeling of the pelvic organs. For this purpose, we provide solutions based on the registration of deformable models on Magnetic Resonance Images (MRI). All the results are able to detect the shape and quantify the movement of a part of the organs and to reconstruct their surfaces from patient-specific MRI. This work facilitates the simulation of the behavior of the pelvic organs using finite element method. The objective of these developed tools is to help to better understand the mechanism of the pathologies. They will finally allow to better predict the presence of certain diseases, as well as make surgical procedures more accurate and personalized
Pescheloche, Michel. "Traitements graphiques informatisés : de nouveaux outils pour automatiser des évaluations dans le secteur santé". Paris 12, 1994. http://www.theses.fr/1994PA120028.
Seror, Oliver. "Adaptation et évaluation du monitorage par IRM de température des ablations hépatiques par radiofréquence". Bordeaux 2, 2006. http://www.theses.fr/2006BOR21331.
In this work the feasibility and the accuracy of MR-thermometry based on the proton resonance frequency shift and using the concept of thermal dose for the monitoring of radiofrequency ablation in the liver were assed. Before the achievement of a clinical pilot study, we carried out three experimental studies : the first was performed ex vivo on liver samples, the second in vivo in the liver of rabbits and the third in vivo in the liver of pigs using clinical available radiofrequency material. Finally the clinical study consisted of the treatment of malignant liver tumours of eight patients by radiofrequency ablation under continuous MR-thermometry monitoring. At each steps of this work Mr-thermometry appeared as a faeasible and reliable monitoring technique to assess in real time the extent of ablation zone during radiofrequency ablation. Further changes in imaging protocol and in the radiofrequency material might improve significantly the effectiveness of this new monitoring imaging
Monchy, Romain de. "Développement et évaluation d'une théorie de milieu effectif combinée à un facteur de structure polydisperse pour la caractérisation ultrasonore de l'agrégation érythrocytaire". Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4762/document.
This thesis aims to develop and evaluate a scattering model for aggregating blood, taking into account the high volume fraction of red blood cells in blood (40%) and the polydispersity in terms of aggregate size. The effective medium theory combined with the monodisperse structure factor model was recently developed to estimate blood microstructure. In order to improve the modeling at high frequency range, we proposed an effective medium theory that takes into account the incoherent component of the scattering by aggregates of RBCs. Three dimensional simulations were performed and showed that the consideration of the incoherent component allows to approximate the simulation satisfactorily for a product of the wavenumber times the aggregates radius $kR$ up to 2. Besides, we proposed an effective medium theory combined with a polydisperse structure factor. From the measured BSC, this model allows to estimate three structural parameters: the mean radius of the aggregate size distribution, the width of the distribution, and the compactness of the aggregates. Experiments were performed on pig blood shared in a Couette device coupled with an ultrasonic probe, and showed that the polydisperse modeling provides better fitting to the experimental BSC data, when compared to the classical monodisperse models. Satisfactory correlation is obtained (r$^2$ $\approx$ 0.92) between the aggregate sizes estimated with ultrasound and the aggregate sizes estimated on the same sample in an optical device
Chopard-Lallier, Sophie. "Suivi fonctionnel de la greffe d'îlots de Langerhans : interêt de l'imagerie IRM et de l'immuno-monitoring cellulaire". Thesis, Besançon, 2013. http://www.theses.fr/2013BESA3001.
Langerhans islet transplantation allows curingtype 1 diabetes by restoring an endogenous insulin secretion. Halfof patients will resume insulin withinyears. This loss of function may be explained by the lack of monitoring tools able to diagnose an ongoing graft failure. The aims of our work were toevaluate the efficiency of MRI to diagnose islet graft rejection, and to assess the feasibility of immune cellular monitoring in transplanted patients.MRI in the rat mortelMethods: Syngeneic, allogeneic and xenogeneic islets were transplanted intra-portally to diabetic rats after labeling with superparamagnetic ironoxide nanoparticles (ferucarbotran). Images were acquired on a clinical 3T MRI scanner.Results: The signal decreasing was different between the 3 types of transplantations. At day 4, the MRI signal in allogeneic group was significantlylower while glycaemia remained normal. With a cut-off value of 84% at day 4, sensitivity of 91% and specificity of 70% were obtained.Cellular immune monitoringMethods: Mixed lymphocyte cultures were performed with peripheral blood mononuclear cells from recipients and splenocytes from donors. Immunereactivity was assessed by the release of IFNy (ELISpot), cell prolifération (flow cytometry of Ki67), and cytokine quantification (Bioplex). Theresults were correlated to the islet graft function assessed by (5-score.Results: Patients with low islet function showed higher cellular reactivity against donor cells assessed by ELISpot IFNy ((p=0,007, r=-0,50) andproliferation index (p=0,006, r=-0,51). Patients with low graft function had higher levels of IFNy, IL-5 and 1L-17