Rozprawy doktorskie na temat „Imagerie multimodalités”
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Cormier, Stéphane. "Classification non exclusive pour le recalage d'images cérébrales multimodalités". Tours, 2000. http://www.theses.fr/2000TOUR3301.
Pełny tekst źródłaLopez-Hernandez, Juan. "Imagerie Cardiaque Multimodalités 2D et 3D :application à la Coronarographie/Tomoscintigraphie/TEP-CT". Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2006. http://tel.archives-ouvertes.fr/tel-00118991.
Pełny tekst źródłaTomography") sont deux techniques d'imagerie utilisées couramment pour diagnostiquer les maladies
cardiovasculaires. La première modalité est constituée de séquences d'images à rayon X visualisant chacune,
dans un même plan, les artères coronaires situées sur la face avant et la face arrière du coeur. Les images à
rayons X fournissent des informations anatomiques liées à l'arbre artériel et mettent en évidence d'éventuels
rétrécissements des artères (sténoses). La modalité SPECT (imagerie nucléaire) fournit une représentation 3D
de la perfusion du volume myocardique. Cette information fonctionnelle permet la visualisation de régions
myocardiques souffrant de défauts d'irrigations. Le but du travail présenté est de superposer, en 3D, les
informations fonctionnelles et anatomiques pour établir un lien visuel entre des lésions artérielles et leurs
conséquences en termes de défauts d'irrigation. Dans la représentation 3D choisie pour faciliter le diagnostic, la
structure d'un arbre artériel schématique, comprenant les sténoses, est placée sur le volume de perfusion. Les
données initiales sont constituées d'une liste de points représentatifs de l'arbre artériel (points d'arrivée et de
départs de segments d'artères, bifurcations, sténoses, etc.) marqués par le coronarographiste dans les images à
rayons X des différentes incidences. Le volume de perfusion est ensuite projeté sous les incidences des images
de coronarographie. Un algorithme de recalage superposant les images à rayons X et les projections SPECT
correspondantes fournit les paramètres des transformations géométriques ramenant les points marqués dans les
images à rayons X dans une position équivalente dans les images SPECT. Un algorithme de reconstruction 3D
permet ensuite de placer les points artériels et les sténoses sur le volume de perfusion et de former un arbre
schématique servant de repère au clinicien. Une base de données formée de 28 patients a été utilisée pour
effectuer 40 superpositions 3D de données anatomo-fonctionnelles. Ces reconstructions ont montré que la
représentation 3D est suffisamment précise pour permettre d'établir visuellement un lien entre sténoses et
défauts de perfusions. Nos algorithmes de superpositions 3D ont ensuite été complétés pour remplacer la
modalité SPECT par les données de l'examen bimodal TEP/CT (Tomographie par Emission de
Positons/Tomodensitométrie). Les données d'un cas clinique trimodal TEP/CT/coronarographie ont été utilisées
pour vérifier l'adéquation de nos algorithmes à la nouvelle modalité d'imagerie.
Lopez, Hernandez Juan Manuel. "Imagerie cardiaque multimodalités 2D et 3D : application à la coronarographie/tomoscintigraphie/TEP-CT". Vandoeuvre-les-Nancy, INPL, 2006. http://docnum.univ-lorraine.fr/public/INPL/2006_LOPEZ_HERNANDEZ_J_M.pdf.
Pełny tekst źródłaCoronarography and tomoscintigraphy (SPECT, Single Photon Emission Tomography) are two imaging techniques used standardly for the diagnosis of cardiovascular diseases. The first modality consists of X-ray image sequences visualizing each, in a same plane, the coronary arteries located on the front and the back side of the heart. The X-ray images give anatomical information relating to the arterial tree and highlight eventual artery narrowings (stenoses). The SPECT modality (nuclear imaging) provide a 3D representation of the myocardial volume perfusion. This functional information authorizes the visualization of myocardial regions suffering from irrigation defaults. The aim of the presented work is to superimpose (in the 3D space) the functional and anatomical information in order to establish the visual link between arterial lesions and their consequence in terms of irrigation defaults. In the 3D representation chosen to facilitate the diagnosis, the structure of a schematic arterial tree and the stenoses are placed onto the perfusion volume. The initial data consist of a list of points representative for the arterial tree (start and end points of arterial segments, bifurcations, stenoses, etc) and marked by coronarographists on the X-ray images of the different incidences. The perfusion volume is then projected under the incidences of the coronarographic images. A registration algorithm superimposing the X-ray images and the corresponding SPECT projections provides the parameters of the geometrical transformations bringing the points marked in the X rays images in equivalent positions in the 2D SPECT images. A 3D reconstruction algorithm is then used to place the arterial points and the stenoses on the perfusion volume and build a schematic tree acting as landmark for the clinician. A 28 patient database was used to realize 40 3D superimposition of anatomo-functional data. These reconstructions have shown that the 3D representation is precise enough for the establishment of the visual relationship between stenoses and perfusion defaults. Our 3D superimposition algorithms were then be completed in order to replace the SPECT modality by data of the PET/CT (Positron Emission Tomography/Computed Tomography) bimodal examination. The data of a clinical trimodal PET/CT/coronarography case have been used to evaluate the adequacy of our algorithms to novel imaging modalities
Palos, Ladeiro Georges. "Recalage non rigide d'images médicales : application aux images abdominales multimodalités". Lille 1, 2004. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2004/50376-2004-73.pdf.
Pełny tekst źródłaPour la réalisation de la méthode nous avons construit un algorithme iconique basé sur les mesures de similarité comme l'information mutuelle et le rapport de corrélation, La mise en œuvre du modèle de déformation d'images nécessite deux étapes: la première étape est un recalage rigide qui permet d'initialiser la seconde, un recalage non rigide basé sur la résolution du flot optique qui offre une certaine simplicité de mise en œuvre, Enfin la dernière partie du document concerne les expérimentations et résultats de la mise en correspondance des images scanner et IRM pour l'utilisation en dosimétrie du traitement en radiothérapie, Les expérimentations que noùs avons réalisées nous permettent d'envisager une adaptation rapide de l'algorithme pour des cas cliniques réels
Brullé, Laura. "Développement de stratégies d'imagerie multimodalités pour la pharmacologie des agents anticancéreux". Phd thesis, Université d'Orléans, 2012. http://tel.archives-ouvertes.fr/tel-00747343.
Pełny tekst źródłaSalazar, Gómez Antonio José. "Développement d'une station d'imagerie médicale multimodalité et multimédia pour la téléradiologie interactive". Compiègne, 1996. http://www.theses.fr/1996COMPD907.
Pełny tekst źródłaFournier-Dujardin, Laure. "Imagerie multimodalité de l'angiogenèse tumorale". Paris 11, 2005. http://www.theses.fr/2005PA112345.
Pełny tekst źródłaAngiogenesis is the formation of new vessels induced by tumours to allow its growth and expansion. It has become the target of a new class of drugs: anti-angiogenic agents. These therapies rarely induce a decrease tumour size. It is therefore necessary to develop new techniques to evaluate functional characteristics of tumours, reflecting their angiogenic status. This purpose of this work was to detect and characterize liver and breast tumours in animal models and in women by quantifying their microvascular characteristics, and to follow anti-angiogenic treatment in human tumours implanted in animals. Several techniques were used in this work. Contrast-enhanced dynamic imaging using Computed Tomography and Magnetic Resonance Imaging yielded parameters reflecting tumour microcirculation, allowing detection and characterization of tumours, and following the effects of therapeutic agents. Optical imaging, which uses light as a diagnostic tool, is still experimental, but it offers new possibilities to define physiological parameters for tissue characterization
Dillenseger, Jean-Louis. "Imagerie Tridimensionnelle Morphologique et Fonctionnelle en Multimodalité". Phd thesis, Université François Rabelais - Tours, 1992. http://tel.archives-ouvertes.fr/tel-00133646.
Pełny tekst źródłaLe premier chapitre est consacré à une étude bibliographique traitant de l'acquisition et de la modélisation de primitives tridimensionnelles en imagerie médicale. Le propos du second chapitre concerne une revue des techniques de représentation de primitives et de fonctions multi-variables.
Le troisième chapitre traite de la représentation et de l'analyse d'images morphologiques tridimensionnelles. Un nouveau concept, le lancer de rayons multi-fonctions, a été introduit afin d'intégrer sur le rayon une partie des traitements tels que l'interpolation, la détection, le filtrage tout en préservant les fonctionnalités de base (dissection, manipulation par exemple) de l'imagerie médicale tridimensionnelle. Une technique d'accélération du processus de synthèse d'images basée sur la cohérence inter-images est également proposée.
Le suivi d'une pathologie ou l'évaluation d'une thérapie nécessitent la confrontation d'images acquises par une même source mais à des instants distincts. Le quatrième chapitre porte sur l'étude et la mise au point d'une technique de recalage 3D en rotation de volumes basée sur une formalisation utilisant les quaternions.
Le dernier chapitre est consacré à la reconstitution et à la description (la visualisation) dans l'espace anatomique cérébral des champs de potentiels électriques ou magnétiques (EEG et MEG).
Laredo, Mikaël. "Nouveaux développements techniques et applications cliniques de l'imagerie par résonance magnétique cardiaque et tomodensitométrie pour le diagnostic et la caractérisation de la cardiomyopathie arythmogène". Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS568.pdf.
Pełny tekst źródłaArrhythmogenic cardiomyopathies (ACM) constitute a spectrum of genetically-determined cardiac diseases of which the main consequence are ventricular arrhythmias potentially leading to sudden cardiac death. Arrhythmogenic cardiomyopathies have a diverse range of clinical-imaging phenotypes, and a continuously evolving landscape including concealed structural changes requiring multiparametric assessment. Cardiac magnetic resonance (CMR) is central in their evaluation, given the growing identification of biventricular and left-ventricular(LV)-predominant ACM variants. Multidetector computed tomography (MDCT), while not as established, offers potential utility as either an adjunct or alternative tool. In this thesis, we took advantage on our large ACM cohort to pursue three aims able to extend the boundaries of cardiac imaging for ACM diagnosis and functional characterization. First, we developed and evaluated a novel feature-tracking CMR parameter that integrates both longitudinal and radial right ventricular (RV) dynamics, which was effective in distinguishing ACM patients, particularly those lacking major structural criteria, from healthy subjects, implying that a two-dimensional representation of RV dynamics is crucial to capture the complex physiology of ACM. Second, we described the CMR features of Desmoplakin (DSP)-related ACM, a specific entity associated with particularly worse outcomes amidst the wide diversity of ACMs, and for the first time compared them to those found in ACM with LV involvement. We found that the presence of diffuse late gadolinium enhancement extending beyond the inferolateral LV combined with an end-systolic LV-to-RV volume ratio ≥0.8 may be considered as indicative of a high pre-genetical test results likelihood for DSP-ACM. Third, through a transversal multimodality study, we showed there was overall a low spatial concordance between the arrhythmogenic substrate and morpho-functional abnormalities or RV fat, at a segmental level. This finding paves the way for an integration of EP data into ACM diagnostic criteria and suggest that routine practice cardiac imaging cannot reliably exclude the presence of an EP substrate in a given RV location. Determinant improvements are currently being undertaken to increase the impact and generalizability of the three sets of results
Benoit, Landry. "Imagerie multimodalité appliquée au phénotypage haut-débit des semences et plantules". Thesis, Angers, 2015. http://www.theses.fr/2015ANGE0084.
Pełny tekst źródłaAlong this work, we have used the potentiality of different modalities of imagery that we apply to the plant domain so as to contribute to the high-throughput phenotyping of seeds and seedlings. We have mainly committed ourselves to the search for answers to two specific and important problematic in this domain. We begin by showing the applicability of visible imaging using an inactinic light and passive thermographic imaging to image the development of seeds and seedlings, a biological phenomenon usually occurring in soil and darkness. We present our contributions to this type of imaging through our contributions to the conception and the realization of a vision system using visible inactinic imaging, whose finality is the realization of individualized automated measurement on the seeds, the seedlings and the organs of the seedlings. This system handle seedling crossing, through the original use of anisotropic diffusion, which allowed us to multiply, without information loss, the output by ten. Furthermore, this system carries out the separation of the organs by means of a generic criterion based on gravitropism. The validation of the image processing algorithms of the vision system use original ways (numerical simulation and test of the influence of the uncertainty through agronomic simulation). Thermographic imaging, which captures the passive heat radiation of objects, allows us to visualize and to measure seeds and seedlings in the darkness. It also allows realizing the segmentation and the tracking of the organs of seedlings. This imaging technology also allowed us to demonstrate the feasibility of a non-destructive determination of sugar quantity in organs of beet seedlings. We then propose a generic methodology that allows the conception of spectrally optimized low-cost sensors, according to determined application tasks. This methodology uses information theory, to extract from, relatively expensive, hyperspectral imaging, the information needed for the conception of the dedicated low-cost sensors. The interest of this methodology for plant phenotyping has been shown and justifies its transfer to the world of research in plant biology
Lopez, Hernandez Juan Manuel Karcher Gilles. "Imagerie cardiaque multimodalités 2D et 3D application à la coronarographie/tomoscintigraphie/TEP-CT /". Vandoeuvre-les-Nancy : INPL, 2006. http://www.scd.inpl-nancy.fr/theses/2006_LOPEZ_HERNANDEZ_J_M.pdf.
Pełny tekst źródłaSoussi, Najib. "Imagerie cardiaque multimodalité IRM - Médecine nucléaire : étude et réalisation d'un protocole automatique de repérage, recalage et fusion d'images cardiaques". Bordeaux 2, 1996. http://www.theses.fr/1996BOR28433.
Pełny tekst źródłaDetraz, Morgane. "Développement d'outils bimodaux pour l'imagerie oncologique in vivo exploitant les modalités optique et nucléaire". Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR138.
Pełny tekst źródłaOncologic healthcare and remission prognosis rely on a reliable and accurate diagnosis. Molecular imaging, including optical and nuclear imaging, is currently used for the management cancer therapy. Recently, a new class of bio-imaging agent called MOMIA (MOnomolecular Multimodal Imaging Agent) emerged by combining the synergistic strengths of several modalities on the same molecular structure. We envisioned to merge optical and nuclear imaging in order to develop a molecular tool offering a non-invasive, highly resolutive and sensitive detection. Our approach relies on a universal bimodal clickable scaffold with a selected targeting ligand. Two distinct enzymatic targets have been explored in the oncologic context: caspase-3 as a key component in an apoptotic program and tyrosine kinase inhibitors involved in lung cancer therapy. These multimodal sensors have a promising potential in translational clinical applications
Forte, Anne-Marie. "Système basé sur la connaissance pour l'identification, la caractérisation et la mise en correspondance d'entités anatomiques et fonctionnelles en imagerie médicale multimodalité". Tours, 1991. http://www.theses.fr/1991TOUR3302.
Pełny tekst źródłaBalvay, Daniel. "Qualité de la modélisation en imagerie dynamique de la microcirculation avec injection d'un agent de contraste : nouveaux critères et applications en multimodalité". Paris 11, 2005. http://www.theses.fr/2005PA112147.
Pełny tekst źródłaThe microcirculation dynamic imaging could be a relevant imaging when used in addition with more conventional medical imaging. The dynamic data are modeled, pixel by pixel, to provide microcirculation parameters maps. However there is no efficient tool to assess the modeling quality. The relevance of the parametric maps provided by the dynamic imaging is then limited. Here, we show that a qualitative and quantitative study of the modeling quality needs first to distinguish two questions : the quality of the data fits and the robusness for the random noise. To separate the questions, we designed a new autocorrelation based method which is able to estimate the amplitude of both the correlated and not correlated component of a signal. This method allowed us to correct the correlation coefficient R² and the covariance matrix estimation. It allowed us to define new reliability criteria and a corrected covariance matrix to replace the more conventional indicators. It was shown, on simulated data and in MR data, that new reliabily criteria are obviously better than the R² to assess fit quality. The corrected covariance matrix which assess the robustness and the redoundancy can be calculated in addition to the reliability criteria unlike conventional one which is limited to good data fits. Thus the modeling quality is obviously improved by the new indicators. It should improve the clinical use of microcirculation dynamic imaging where guaranties are needed against artefact. The interest of the new criteria is showed on many different dynamic data. More generaly the new indicators appear as new efficient tools for signal analysis
Hendlisz, Alain. "Multimodality imaging for treatment response prediction in colorectal cancer". Doctoral thesis, Universite Libre de Bruxelles, 2015. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209109.
Pełny tekst źródła1) Le premier projet explore l’imagerie multimodale comme un outil d’individualisation pour la radio-embolisation (microsphères chargées en 90Yttrium) chez des patients porteurs d’un CCR métastatique au niveau du foie, pour laquelle l’imagerie morphologique classique est incapable de mesurer l’effet thérapeutique. Nous montrons que l’usage non sélectif de la radio-embolisation améliore l’histoire clinique de ces patients, bien que certains d’entre eux ne semblent pas en bénéficier. Ensuite, par une analyse multimodale lésion par lésion intégrant angiographie-CT Scan, FDG-PET/CT et scintigraphie aux macro-agrégats d’albumine marqués au 99mTechnetium, nous démontrons que la distribution pré-thérapeutique des macro-agrégats d’albumine est hétérogène entre les différentes lésions des patients et prédictive de la réponse métabolique au sein de ces lésions, permettant le développement d’un outil de prédiction et de planification pour la radio-embolisation.
2) Le deuxième projet explore le domaine du CCR métastatique traité par chimiothérapie palliative. (i) Nous démontrons d’abord que la réponse métabolique (RM) tumorale après une cure de chimiothérapie cytolytique prédit plus vite et plus adéquatement que l’imagerie morphologique basée sur les critères RECIST les bénéfices cliniques du traitement. La RM précoce a une excellente valeur prédictive négative sur l’absence de réponse morphologique et met en évidence une variabilité de réponse inter-lésionnelle chez une proportion importante des patients. (ii) L’étude SoMore explore ensuite des patients présentant un CCR avancé et réfractaire, traités par capecitabine et sorafenib, et confirme l’importance pronostique des RM mixtes, suggérant une méthodologie de classification clinique basée sur la consistance de la RM. (iii) Cette classification cherche confirmation dans l’étude RegARd-C, encore en cours, évaluant les effets du regorafenib, et explorant également la signification génomique et épigénétique de la variabilité de RM.
3) Le troisième projet cherche à utiliser les propriétés de l’imagerie métabolique pour modifier l’algorithme de traitement adjuvant des patients porteurs d’un cancer du côlon de stade III. Ce projet, encore en cours, fait l’hypothèse que l’absence de RM de la lésion primitive après une cure de chimiothérapie prédit l’absence de bénéfice du traitement adjuvant complet. Une analyse intérimaire en démontre la faisabilité et confirme la présence de 40% de tumeurs présentant des caractéristiques métaboliques de chimio-résistance.
En conclusion, pour des patients porteurs d’un CCR, l’imagerie multimodale comprenant une évaluation du métabolisme tumoral permet une évaluation plus précoce et plus adéquate du bénéfice au traitement anticancéreux pour différentes modalités thérapeutiques comme la radio-embolisation, la chimiothérapie cytotoxique et les agents biologiques. L’imagerie multimodale permet de prédire et planifier les radio-embolisations et se révèle très prometteuse pour les traitements chimiothérapiques cytotoxiques ou combinés à des biologiques en situation adjuvante ou métastatique. Elle démontre par ailleurs une importante variabilité de réponse métabolique inter-lésionnelle qui représente un axe de recherche majeur sur les mécanismes moléculaires d’hétérogénéité génomique tumorale et de résistance aux traitements anti-cancéreux.
Doctorat en Sciences médicales
info:eu-repo/semantics/nonPublished
Dentamaro, Mario. "Développement de fonctionnalisations biochimiques de nanoparticules théranostiques pour un ciblage actif de l’apoptose". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1127.
Pełny tekst źródłaAGuIX® nanoparticles are small platforms of polysiloxane developed for applications in medical imaging. These nanoparticles present on their surface several amine functions used for the grafting of Gd-DOTA complexes. These paramagnetic platforms have a diameter less than 5 nm. Different studies have been achieved showing that they allow to combine multimodal diagnosis and theranostic properties with a passive tumoral targeting observed by EPR effect (Enhanced Permeability and Retention). Otherwise, their small size allows a quick body excretion by the kidneys. The low transmetalation rate of Gd3+ ions complexed by DOTA provides negligible toxicological effects in pre-clinical studies.Some studies showed that TLVSSL peptide has a high affinity for phosphatidylserine, a phospholipid overexposed on cells in apoptosis process of death. The targeting of apoptotic cells is interesting to follow the efficiency of an antitumoral therapy and for diagnosis of diseases related to this process. In this work, AGuIX nanoparticles have thus been grafted with this peptide and characterized (AGuIX-E3). To increase the peptide mobility against the rigid platform, AGuIX were also grafted with peptides bound to a linker through an amide bond with 8-amino-3,6-dioxaoctanoic acid, (AGuIX-L-E3) and with a peptide scramble (AGuIX-E3Sc, AGuIX-L-E3Sc).AGuIX® nanoparticles were grafted with peptide by activation with EDC of the carboxylic functions available on nanoparticle surface. Furthermore, previous addition of an optical dye allows their applications in optical imaging (rhodamine or cyanine 5.5). Different physicochemical techniques such as PCS, fluorescence spectroscopy, HPLC and proton relaxometry were used to characterize these platforms. Relaxometric studies by NMRD profiles confirmed the increase of the rotational correlation time after linking of peptide and allow to study the time stability of the platform. Biological tests were performed using fluorescence microscopy, relaxometry and flow cytometry techniques to determine the affinity of nanoparticles for lymphoblastic human T cell line (Jurkat) cells overexposing phosphatidylserine, suggesting an efficiency to target apoptosis. In vitro cell apoptosis was chemically induced by incubation with campthothecin. However, though in vitro analysis confirmed the real impact of the grafting of AGuIX on the efficiency to target apoptosis, first in vivo studies didn’t showed a significant influence of peptide when nanoparticles (AGuIX, AGuIX-E:), AGuIX-E3Sc) were injected on mice. Injected-mice were previously treated with dexamethasone to trigger apoptosis in thymus. In conclusion, several chemical characterizations and biological tests achieved on our research confirmed the binding of peptides on AGuIX nanoparticles. In vitro analyses have showed an efficient targeting of cells with overexposed phosphatidylserine by graftedAGuIX nanoparticles. Nevertheless, in vivo experiments didn't confirm the conclusion suggested in vitro tests. Indeed, the intake of active targeting of apoptotic cells by graftedAGuIX is not relevant in front of the non-specific targeting observed with non-grafted AGuIX. Further in vivo tests should be however achieved to confirm these observations
Anxionnat, René. "Méthodes et outils pour le détourage des malformations artério-veineuses cérébrales dans un contexte multimodalité". Nancy 1, 2003. http://www.theses.fr/2003NAN10154.
Pełny tekst źródłaRadiosurgery of brain arteriovenous malformations (AVM) requires a precise localization of the volume of the AVM. This volume is at present reconstructed by cone intersection from the manual delineations performed by a medical expert in 2D digital subtracted angiographic (2DSA) views. Regarding the often complex shape of the AVM and the few number of views the resulting volume is far from the actual shape. Moreover the difficulties in the delineation led to an important inter and intra-observer variability. The aim of this study was to develop a new method using 3D imaging and improving the accuracy of this volume determination. We first focused on the validation of 3D X-ray angiography (3DXA) as a 3D imaging modality for delineation of the AVM. This validation presented with difficult problems of methodology. We compared the delineations performed in 3DXA with those performed in 2DSA taken as the reference. In practice we constructed statistical models derived from a set of 3 experts delineations on 2DSA in a clinical database of AVMs treated by radiosurgery. Then, using this shape database as a reference, we evaluate 3DXA delineations performed by the same experts. For that purpose we designed a statistical test for acceptation/rejection of these 3DXA delinations. The results proved that 3DXA could be used for AVMs delineation. We then developed a new method using deformable surfaces applied to 3DXA volume in order to refine the initial estimate of the volume provided by the delineations in 2DSA views. The resulting volumes well matched the reference shape database and demonstrated an important reduction of the inter-observer variability. We now plan to test this method on a large range of MAVs. Moreover we have to keep on the beginning works on the use of 3D MRI
Chauvet, Cindy. "Fusion TEMP-TDM en imagerie cardiaque : vers une sectorisation spécifique de la perfusion myocardique". Thesis, Clermont-Ferrand 1, 2011. http://www.theses.fr/2011CLF1MM10.
Pełny tekst źródłaNo abstract available
Nardecchia, Alessandro. "Chemometric exploration in hyperspectral imaging in the framework of big data and multimodality". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. https://pepite-depot.univ-lille.fr/LIBRE/EDSMRE/2022/2022ULILR021.pdf.
Pełny tekst źródłaNowadays, it is widely known that hyperspectral imaging is a very good tool used in many chemical-related research areas. Indeed, it can be exploited for the study of samples of different nature, whatever the spectroscopic technique used. Despite the very interesting characteristics related to this kind of acquired data, various limitations are potentially faced. First of all, modern instruments can generate a huge amount of data (big datasets). Furthermore, the fusion of different spectroscopic responses on the same sample (multimodality) can be potentially applied, leading to even more data to be analyzed. This aspect can be a problem, considering the fact that if the right approach is not used, it could be complicated to obtain satisfying results or even lead to a biased vision of the analytical reality of the sample. Obviously, some spectral artifacts can be present in a dataset, and so the correction of these imperfections has to be taken into account to carry out good outcomes. Another important challenge related to the use of hyperspectral image analysis is that normally, the simultaneous observation of spectral and spatial information is almost impossible. Clearly, this leads to an incomplete investigation of the sample of interest. Chemometrics is a modern branch of chemistry that can perfectly match the current limitations related to hyperspectral imaging. The purpose of this PhD work is to give to the reader a series of different topics in which many challenges related to hyperspectral images can be overcome using different chemometric facets. Particularly, as it will described, problems such as the generation of big amount of data can be faced using algorithms based on the selection of the purest information (i.e., SIMPLISMA), or related to the creation of clusters in which similar components will be grouped (i.e., KM clustering). In order to correct instrumental artifacts such as saturated signals will be used a methodology that exploits the statistical imputation, in order to recreate in a very elegant way the missing information and thus, obtain signals that otherwise would be irremediably lost. A significant part of this thesis has been related to the investigation of data acquired using LIBS imaging, a spectroscopic technique that is currently obtaining an increasing interest in many research areas, but that, still, has not really been exploited to its full potential by the use of chemometric approaches. In this manuscript, it will be shown a general pipeline focusing on the selection of the most important information related to this kind of data cube (due to the huge amount of spectral data that can be easily generated) in order to overcome some limitations faced during the analysis of this instrumental response. Furthermore, the same approach will be exploited for the data fusion analysis, related to LIBS and other spectroscopic data. Lastly, it will be shown an interesting way to use wavelet transform, in order to not limit the analysis only to spectral data, but also to spatial ones, to obtain a more complete chemical investigation
El, Azami Meriem. "Computer aided diagnosis of epilepsy lesions based on multivariate and multimodality data analysis". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI087/document.
Pełny tekst źródłaOne third of patients suffering from epilepsy are resistant to medication. For these patients, surgical removal of the epileptogenic zone offers the possibility of a cure. Surgery success relies heavily on the accurate localization of the epileptogenic zone. The analysis of neuroimaging data such as magnetic resonance imaging (MRI) and positron emission tomography (PET) is increasingly used in the pre-surgical work-up of patients and may offer an alternative to the invasive reference of Stereo-electro-encephalo -graphy (SEEG) monitoring. To assist clinicians in screening these lesions, we developed a computer aided diagnosis system (CAD) based on a multivariate data analysis approach. Our first contribution was to formulate the problem of epileptogenic lesion detection as an outlier detection problem. The main motivation for this formulation was to avoid the dependence on labelled data and the class imbalance inherent to this detection task. The proposed system builds upon the one class support vector machines (OC-SVM) classifier. OC-SVM was trained using features extracted from MRI scans of healthy control subjects, allowing a voxelwise assessment of the deviation of a test subject pattern from the learned patterns. System performance was evaluated using realistic simulations of challenging detection tasks as well as clinical data of patients with intractable epilepsy. The outlier detection framework was further extended to take into account the specificities of neuroimaging data and the detection task at hand. We first proposed a reformulation of the support vector data description (SVDD) method to deal with the presence of uncertain observations in the training data. Second, to handle the multi-parametric nature of neuroimaging data, we proposed an optimal fusion approach for combining multiple base one-class classifiers. Finally, to help with score interpretation, threshold selection and score combination, we proposed to transform the score outputs of the outlier detection algorithm into well calibrated probabilities
Faraj, Achraf Al. "Biodistribution and biological impact of nanoparticles using multimodality imaging techniques : (Magnetic resonance imaging)". Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00696221.
Pełny tekst źródłaOhene-Larbi, Stephen. "Harnessing Multimodality in First-Year Composition Classroom in Second Language (L2) Settings to Enhance Effective Writing". Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1573566926659647.
Pełny tekst źródłaFaghihi, Reza. "Mise en correspondance SPECT-CT par conditions de consistance". Université Joseph Fourier (Grenoble), 2002. http://www.theses.fr/2002GRE19011.
Pełny tekst źródłaHe, Linbo. "Improving 3D Point Cloud Segmentation Using Multimodal Fusion of Projected 2D Imagery Data : Improving 3D Point Cloud Segmentation Using Multimodal Fusion of Projected 2D Imagery Data". Thesis, Linköpings universitet, Datorseende, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-157705.
Pełny tekst źródłaLussey, Charlotte. "Apport de l'imagerie multimodale à l'étude de l'angiogenèse et du métabolisme des tumeurs liées aux mutations SDHB". Thesis, Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCB151/document.
Pełny tekst źródłaPheochromocytomas and paragangliomas (PCC/PGL) are rare neuroendocrine tumours that arise from chromaffin cells of the adrenal medulla, sympathetic and parasympathetic paraganglia respectively. Around 15% of PCC are malignant. SDHB mutations are associated with malignancy and poor prognosis. SDH deficiency leads to succinate accumulation that induces a cellular pseudohypoxic phenotype, promoting in particular VEGF and GLUT-1 expression and increasing angiogenesis and glucose metabolism. The high malignancy hazard associated with SDHB and the absence of curative treatment of metastatic forms of the disease make it essential to develop a mouse model for preclinical trials launching. The quest for a predisposed mouse model of Sdhb-deficient tumors being unsuccessful, Sdhb-/- and wild-type (WT) immortalized mouse chromaffin cells previously generated in the laboratory were propagated in the fat pad of NMRI nude mice, thereby providing the first pattern of Sdhb- deficient tumors. These mice were compared to a control group receiving non-mutated imCC (WT) and characterization was performed in vivo by multimodality imaging. Optical imaging assessing the tumor angiogenesis with Angiostamp®, an RGD fluorescent peptide, found an increased expression of integrins αvβ3 in the Sdhb-/- group 12 h after tracer injection. Dynamic contrast enhanced MRI (DCE-MRI) showed an overall tumor enhancement significantly higher in the Sdhb-/- model secondary to an increase of the tumor blood flow (F) and of the intratumoral capillary volume fraction (Vb) (compartmental analysis using PhysioD3D software). Metabolic imaging assessed by 18FDG-PET confirmed the expected high glucose consumption by Sdhb-/- tumors. Finally, magnetic resonance spectroscopy (1H-MRS) detected succinate accumulation in Sdhb-/- tumors and not in WT tumors. This result was confirmed by mass spectrometry and this innovative procedure for in vivo detection of succinate was translated into patients suffering from PCC/PGL. A succinate peak was specifically observed in SDHx-related PCC/PGL patients. In conclusion, these results show strong differences between Sdhb-/- and WT allografts and suggest that preclinical therapeutic studies could be implemented in this unique model of Sdhb-deficient tumour. Our noninvasive, highly sensitive and specific method allowing in vivo detection of succinate, the major biomarker of SDHx-mutated tumors was translated into clinical imaging
Hueber, Thomas. "Reconstitution de la parole par imagerie ultrasonore et vidéo de l'appareil vocal : vers une communication parlée silencieuse". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2009. http://pastel.archives-ouvertes.fr/pastel-00005707.
Pełny tekst źródłaHett, Kilian. "Multi-scale and multimodal imaging biomarkers for the early detection of Alzheimer’s disease". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0011/document.
Pełny tekst źródłaAlzheimer’s disease (AD) is the most common dementia leading to a neurodegenerative process and causing mental dysfunctions. According to the world health organization, the number of patients having AD will double in 20 years. Neuroimaging studies performed on AD patients revealed that structural brain alterations are advanced when the diagnosis is established. Indeed, the clinical symptoms of AD are preceded by brain changes. This stresses the need to develop new biomarkers to detect the first stages of the disease. The development of such biomarkers can make easier the design of clinical trials and therefore accelerate the development of new therapies. Over the past decades, the improvement of magnetic resonance imaging (MRI) has led to the development of new imaging biomarkers. Such biomarkers demonstrated their relevance for computer-aided diagnosis but have shown limited performances for AD prognosis. Recently, advanced biomarkers were proposed toimprove computer-aided prognosis. Among them, patch-based grading methods demonstrated competitive results to detect subtle modifications at the earliest stages of AD. Such methods have shown their ability to predict AD several years before the conversion to dementia. For these reasons, we have had a particular interest in patch-based grading methods. First, we studied patch-based grading methods for different anatomical scales (i.e., whole brain, hippocampus, and hippocampal subfields). We adapted patch-based grading method to different MRI modalities (i.e., anatomical MRI and diffusion-weighted MRI) and developed an adaptive fusion scheme. Then, we showed that patch comparisons are improved with the use of multi-directional derivative features. Finally, we proposed a new method based on a graph modeling that enables to combine information from inter-subjects’ similarities and intra-subjects’ variability. The conducted experiments demonstrate that our proposed method enable an improvement of AD detection and prediction
Desbrée, Aurélie. "Nouvelle approche multimodale et quantitative pour les études in vivo chez le petit animal : couplage de la β-MicroProbe aux techniques magnétiques et développement de fantômes de rat et de souris voxelisés". Paris 7, 2005. https://tel.archives-ouvertes.fr/tel-00115911.
Pełny tekst źródłaBARRA, Vincent. "Fusion d'images 3D du cerveau - Etude de modèles et applications". Phd thesis, Université d'Auvergne - Clermont-Ferrand I, 2000. http://tel.archives-ouvertes.fr/tel-00005976.
Pełny tekst źródłaMari, Emilie. "Biosensor activatable in both fluorescence and 129Xe NMR for detection of recombinant proteins". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLV067/document.
Pełny tekst źródłaFull understanding of intracellular phenomena involves sensitive and non-invasive detection. A less disruptive method than labeling with fluorescent proteins uses binding between a tag of only six natural amino acids that can be genetically incorporated into the protein of interest and a small molecule called FlAsH. This molecule has the ability to fluoresce only when it binds to its tetracysteine target. Another technique based on 129Xe NMR has emerged. Xenon is hyperpolarized to enhance the NMR signal by orders of magnitude and its reversible encapsulation in functionalized host systems gives it a specific spectral signature. Capability of the noble gas to cross cell membranes without losing its polarization enables in cellulo investigations.This doubly smart probe is highly promising for monitoring, studying, detecting recombinant proteins. Structural, chemical and lateral resolutions are combined by the bimodality of this new concept, which can be extended to in cellulo detection
Wojak, Julien. "Analyse d'images multi-modales TEP-TDM du thorax. Application à l'oncologie : segmentation de tumeurs, d'organes à risque et suivi longitudinal pour la radiothérapie". Phd thesis, Télécom ParisTech, 2010. http://pastel.archives-ouvertes.fr/pastel-00567100.
Pełny tekst źródłaDesbrée, Aurélie. "Nouvelle approche multimodale et quantitative pour les études in vivo chez le petit animal : couplage de la $\beta$-MicroProbe aux techniques magnétiques etdéveloppement de fantômes de rat et de souris voxelisés". Phd thesis, Université Paris-Diderot - Paris VII, 2005. http://tel.archives-ouvertes.fr/tel-00115911.
Pełny tekst źródład'étudier ces modèles au cours du temps a stimulé le développement d'instruments dédiés aux études in vivo chez le petit animal. Pour aller plus loin dans la compréhension des mécanismes physiopathologiques, le grand défi actuel est de pouvoir coupler simultanément
plusieurs de ces méthodes. Dans ce cadre, la combinaison des techniques magnétiques et radioactives reste un challenge des plus intéressants mais aussi des plus délicats à réaliser techniquement. C'est pourquoi nous proposons de coupler les techniques magnétiques à la sonde radiosensible b-MicroProbe développée dans le groupe IPB et qui s'est révélée être une alternative aux mesures TEP. Dans ce contexte, le travail de thèse a consisté à étudier la faisabilité de ce couplage d'un point de vue physique, par simulation et par des caractérisations expérimentales. Puis, la mise en place d'un protocole biologique a été effectuée sur la base d'études pharmacocinétiques. Les expériences menées ont montré la possibilité d'utiliser la sonde pour des mesures radioactives sous champ magnétique intense
simultanément à l'acquisition d'images anatomiques. Parallèlement, nous avons cherché à améliorer la quantification du signal radioactif grâce à l'utilisation d'un fantôme voxelisé de cerveau de rat. Enfin, l'émergence des modèles transgéniques nous a conduit à reproduire des études pharmacocinétiques chez la souris et à développer des fantômes voxelisés de souris.
Teston, Eliott. "Nanohybrides superparamagnétiques à luminescence persistante : conception et application au marquage cellulaire pour la vectorisation magnétique in vivo". Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB025/document.
Pełny tekst źródłaCell therapy aims to use cells as injectable medicines in order to enhance damaged organs or tissues repair. Some cells have the ability to promote new blood vessels growth. Therefore, they have an interest in revascularization of ischemic tissues and are potential candidates for cell therapy in peripheral ischemia or myocardial infarction. Being able to determine these cell's fates after in vivo injection is a major step to better understand the mechanisms of such treatments efficiency. However, following this phenomenon is challenging and rarely described in scientific litterature. Only some applications of nanotechnologies to follow labeled cells in vitro have been published. But limitations as implementation complexity or a low sensitivity prevent from using these techniques in vivo. This phD work describes the development of new hybrids nanoparticules associating optical and magnetic resonance imaging modalities in order to efficiently label cells that have a therapeutic potential. Developed protocols allowed us to follow magnetic cell vectorisation after injection in mice in real time
Brunie, Lionel. "Fusion d'images médicales multimodales : application à l'étude tridimensionnelle dynamique de la colonne vertébrale". Grenoble 1, 1992. http://www.theses.fr/1992GRE10195.
Pełny tekst źródłaInácio, Adriana da Silva Araújo. "Aprendizagem da leitura a partir de material multimodal visando à construção de sentido". Universidade Federal de Sergipe, 2016. https://ri.ufs.br/handle/riufs/6431.
Pełny tekst źródłaThis dissertation takes as a starting point the fact that the process of constructing meanings in multimodal texts involves the contribution of verbal and non-verbal codes, which integrate themselves in a collaborative action in order to establish communication. Therefore, explicit/implicit elements add up to the textual composition in meaningful arrangements materializedinto texts (re)createdby the reading subject. It is important to highlight that this process depends on the reader’s repertoire which involves linguistics, discourse and image knowledge. For this reason, we have chosen to develop a group of 9th grade students with whom I work at a public school in Aracaju verbal and visual language literacy aiming to improve their reading competence and reflexive thinking. For the purpose of achieving such scope, we have developed the digital game Na Trilha dos sentidos, directed into building meanings from strips and publicity ads, both multimodal kinds of texts. We have been supported by the social interactionist linguistic theories related to the conception of genre by Marcuschi (2008); we have resorted to Koch (2006, 2015) to debate the concept of resumption by the pronominal anaphora; we have sought the basis for a concept of reading in Kleiman (2000); we have read Cavalcante e Custódio (2010) for the concept of text and Bakhtin/Volochinov (1998 [1929]) for information about the discursive context and dialogism; Kress e Van Leeuwen (1996) have made it possible for us to organize the visual resources studies, among which we stress salience and framing; besides using Fialho’s ideas (2005) for the pedagogic game as an auxiliary resource functionality, a motivation in the learning process. The study followed the principles of the educational actionresearch, defined by Tripp (2005) as a strategy for developing teachers who aim at enhancing their teaching practices and, consequently, their students’ learning. This theoretical input has contributed for the elaboration of the tasks in the game created by researcher. We have observed, from the application and outcomes analysis, that using this pedagogic resource has leaded to students’ involvement with contents, resulting in a broader comprehension of materials in which linguistic, discursive and imagetic aspects have collaborated in the constitution of a single verbal and visual text. We have also noticed the enhancement of the interpretation of meanings from inferences built by means of diverse language resources combined analysis. In spite of its limited reach, as it was restricted to only one group of students, this research suggests that the use of pedagogic practices with multimodal materials based in games should be increased, as it collaborates with the enlargement of the elementary school students’ comprehension ability.
Esta dissertação toma como ponto de partida o fato de o processo de construção de sentido nos textos multimodais envolver a contribuição de códigos verbais e não verbais, que se integram em ação colaborativa para estabelecer comunicação. Assim, elementos explícitos/implícitos integram a composição textual em arranjos significativos materializados em textos que são (re)criados pelo sujeito leitor. É importante destacar que esse processo depende do repertório de conhecimentos que envolve saberes linguísticos, discursivos e imagéticos. Por essa razão, optamos por desenvolver o letramento dos estudantes na linguagem verbo-visual visando ao aprimoramento da competência leitora e do pensamento reflexivo de estudantes do 9º ano do ensino fundamental com os quais trabalho em uma escola pública de Aracaju. Para atingir tal escopo, desenvolvemos o jogo digital Na Trilha dos sentidos, direcionado à construção de sentido a partir dos gêneros tira e anúncio publicitário, ambos de natureza multimodal. Apoiamo-nos nas teorias linguísticas sociointeracionistas associadas à concepção de gênero de Marcuschi (2008); recorremos a Koch (2006, 2015) para discutir a concepção de retomada pela anáfora pronominal; buscamos em Kleiman (2000) as bases para uma concepção de leitura; partimos de Cavalcante e Custódio (2010) para definirmos o conceito de texto e em Bakhtin/Volochinov (1998 [1929]) para o de contexto discursivo e dialogismo; Kress e Leeuwen (2006) possibilitaram-nos organizar os estudos dos recursos visuais, entre os quais destacamos a saliência e o enquadre; além de utilizarmos as ideias de Fialho (2005) para funcionalidade do jogo didático como recurso auxiliar, motivacional no processo da aprendizagem. O trabalho realizado seguiu os princípios da pesquisa-ação educacional, conforme Tripp (2005), que a define como uma estratégia de desenvolvimento de professores que visam a aprimorar as estratégias de ensino que utilizam e, consequentemente, as aprendizagens dos estudantes. Esse aporte teórico contribuiu para a elaboração das atividades do jogo criado pela pesquisadora. Constatamos a partir da aplicação do jogo e análise dos resultados que a utilização desse tipo de recurso didático promoveu o envolvimento dos estudantes com os conteúdos estudados, resultando em uma maior compreensão de materiais nos quais aspectos linguísticos, discursivos e imagéticos colaboram para a constituição de um único texto verbo-visual. Também notamos o aprimoramento da interpretação de sentidos a partir de inferências construídas por meio de análise combinada de diferentes recursos de linguagem. Embora com alcance limitado, por estar restrito a uma única turma, esta pesquisa possibilita sugerir que haja o incremento de práticas pedagógicas com materiais multimodais apoiadas em jogos, pois colaboram com a ampliação das capacidades de compreensão dos estudantes da educação básica.