La microscopie à éclairements structurés(structured illumination microscopy, SIM) permet de dépasser la limite de résolution en microscopie optique due à la diffraction, en éclairant l’objet avec un ensemble de motifs périodiques parfaitement connus. Cependant, il s’avère difficile de contrôler exactement la forme des motifs éclairants. Qui plus est, de fortes distorsions de la grille de lumière peuvent être générées par l’échantillon lui-même dans le volume d’étude, ce qui peut provoquer de forts artefacts dans les images reconstruites. Récemment, des approches dites blind-SIM ont été proposées, où les images sont acquises à partir de motifs d’éclairement inconnus, non-périodiques, de type speckle,bien plus faciles à générer en pratique. Le pouvoir de super résolution de ces méthodes a été observé, sans forcément être bien compris théoriquement. Cette thèse présente deux nouvelles méthodes de reconstruction en microscopie à éclairements structurés inconnus (blind speckle-SIM) : une approche conjointe et une approche marginale. Dans l’approche conjointe, nous estimons conjointement l’objet et les motifs d’éclairement au moyen d’un modèle de type Basis Pursuit DeNoising (BPDN) avec une régularisation en norme lp,q où p=>1 et 0<q<=1. La norme lp,q est introduite afin de prendre en compte une hypothèse de parcimonie sur l’objet. Dans l’approche marginale, nous reconstruisons uniquement l’objet et les motifs d’éclairement sont traités comme des paramètres de nuisance. Notre contribution est double. Premièrement, une analyse théorique démontre que l’exploitation des statistiques d’ordre deux des données permet d’accéder à un facteur de super résolution de deux, lorsque le support de la densité spectrale du speckle correspond au support fréquentiel de la fonction de transfert du microscope. Ensuite, nous abordons le problème du calcul numérique de la solution. Afin de réduire à la fois le coût de calcul et les ressources en mémoire, nous proposons un estimateur marginal à base de patches. L’élément clé de cette méthode à patches est de négliger l’information de corrélation entre les pixels appartenant à différents patches. Des résultats de simulations et en application à des données réelles démontrent la capacité de super résolution de nos méthodes. De plus, celles-ci peuvent être appliquées aussi bien sur des problèmes de reconstruction 2D d’échantillons fins, mais également sur des problèmes d’imagerie 3D d’objets plus épais. / Conventional structured illumination microscopy (SIM) can surpass the resolution limit inoptical microscopy caused by the diffraction effect, through illuminating the object with a set of perfectly known harmonic patterns. However, controlling the illumination patterns is a difficult task. Even worse, strongdistortions of the light grid can be induced by the sample within the investigated volume, which may give rise to strong artifacts in SIM reconstructed images. Recently, blind-SIM strategies were proposed, whereimages are acquired through unknown, non-harmonic,speckle illumination patterns, which are much easier to generate in practice. The super-resolution capacity of such approaches was observed, although it was not well understood theoretically. This thesis presents two new reconstruction methods in SIM using unknown speckle patterns (blind-speckle-SIM): one joint reconstruction approach and one marginal reconstruction approach. In the joint reconstruction approach, we estimate the object and the speckle patterns together by considering a basis pursuit denoising (BPDN) model with lp,q-norm regularization, with p=>1 and 0<q<=1. The lp,q-norm is introduced based on the sparsity assumption of the object. In the marginal approach, we only reconstruct the object, while the unknown speckle patterns are considered as nuisance parameters. Our contribution is two fold. First, a theoretical analysis demonstrates that using the second order statistics of the data, blind-speckle-SIM yields a super-resolution factor of two, provided that the support of the speckle spectral density equals the frequency support of the microscope point spread function. Then, numerical implementation is addressed. In order to reduce the computational burden and the memory requirement of the marginal approach, a patch-based marginal estimator is proposed. The key idea behind the patch-based estimator consists of neglecting the correlation information between pixels from different patches. Simulation results and experiments with real data demonstrate the super-resolution capacity of our methods. Moreover, our proposed methods can not only be applied in 2D super-resolution problems with thin samples, but are also compatible with 3D imaging problems of thick samples.

Dans cette thèse, différents aspects de la propagation de lumière en milieux hétérogènes sont abordés. Dans un premier temps, les concepts et les outils fondamentaux de la propagation des ondes en milieux désordonnés sont rappelés.Ensuite, le régime de localisation d'Anderson est abordé pour des systèmes bidimensionnels ouverts. La localisation est mise en évidence de manière simple à partir du calcul de la figure de speckle transmis par une réalisation unique du désordre et en faisant varier les conditions d'illumination. Les régimes localisé et diffusif sont alors nettement différenciés, permettant d'introduire un nouveau critère pour la localisation.Puis, un régime dilué dans lequel les corrélations du désordre jouent un rôle important est étudié. En particulier, l'étude se concentre sur les milieux hyperuniformes, qui permettent de montrer de manière spectaculaire comment les corrélations peuvent changer les propriétés de diffusion d'un milieu jusqu'à le rendre totalement transparent. L'influence des corrélations du désordre sur le coefficient d'absorption d'un milieu désordonné est également envisagée, elle s'avère être modérée.La dernière partie s'intéresse aux fluctuations du taux d'émission d'un émetteur de type molécule fluorescente enfoui dans un milieu désordonné en fonction de sa position. Cette corrélation spatiale d'un nouveau genre permet d'obtenir de manière découplée des informations sur les détails microscopiques du milieu (corrélations) et l'environnement local de la source. / In this thesis, different aspects of wave propagation in complex media are adressed. First, basicconcepts and tools of the propagation of waves in disordered media are reminded.Then, the Anderson localization regime is tackled for two-dimensional open systems. The localization is highlighted in a simple way from a calculation of the transmitted speckle pattern for a single configuration of the disorder with varying illumination conditions. Localized and diffused regimes are clearly differenciated, allowing to introduce a new critria for localization.Next, a weak scattering regime for which correlations of the disorder play a significant role is investigated. Namely, the study is focused on hyperuniform materials, where correlations are such that they are transparent compared with their uncorreleted equivalent. The influence of the correlations of the disorder on the absorption coefficient is also considered, but it is found to be moderated.The final part is dedicated to the fluctuations of the decay rate of an emitter, (e. g. fluorescentmolecule), embedded in a disordered medium as a function of its position. This new type of spatialcorrelation allows to extract information on the microscopic details of the medium (correlations) and the local environment of the source in an uncoupled way.

A doença arterial coronária é importante e prevalente manifestação da aterosclerose. A avaliação da função diastólica pelos parâmetros mitrais obtidos com Doppler ecocardiográfico possui limitações nos coronariopatas com fração de ejeção do ventrículo esquerdo (FEVE) preservada. Nestes, a disfunção diastólica, independentemente da FEVE, associa-se a maior incidência de desfechos desfavoráveis. A elevação da pressão diastólica final (PD2) do ventrículo esquerdo (VE) é a principal consequência fisiológica da disfunção diastólica. A pesquisa por melhores formas de determinação da PD2 do VE estendeu-se às modernas técnicas ecocardiográficas de quantificação da mecânica cardíaca. O objetivo deste estudo é correlacionar as medidas de deformação miocárdica, obtidas pelo speckle-tracking ecocardiográfico bidimensional, com a medida invasiva da PD2 do VE em pacientes com insuficiência coronariana e FEVE preservada. Métodos: foram avaliados 81 coronariopatas (idade: 61 ±8 anos) com FEVE >50%, encaminhados para cineangiocoronariografia eletiva, 40 destes com PD2 elevada (>16 mm Hg). Todos os indivíduos foram submetidos à avaliação ecocardiográfica convencional imediatamente antes do cateterismo e subsequente avaliação offline, com ecocardiografia speckle tracking (EST) para obtenção de medidas sistólicas e diastólicas de strain e strain rate circunferenciais e longitudinais, e estudo rotacional do VE. Foram analisadas as variáveis diastólicas da EST, tanto de forma isolada, quanto combinada com a velocidade da onda E ao Doppler. Resultados: Comparativamente, os pacientes do grupo com PD2 do VE elevada (n=40) mostraram aumento do volume indexado do átrio esquerdo (22 ±6 mL vs 26 ±8,26 mL p=0,04), velocidade da onda E (65 ±15 cm/s vs 78 ±20 cm/s p=0,02), relação E/e\' médio (8,14 ±2,0 vs 11,54 ±2,7 p=0,03) e relação E/strain rate global circunferencial (SRGC) pico E (39 cm vs 46 cm p <0,01). Nos 81 pacientes a correlação de Spearman com a medida invasiva da PD2 do VE foi de 0,56 para a relação E/e\' (p=0,03) e de 0,43 para a relação E/ESRGC pico E (p<0,01). A área sob a curva ROC foi significativa em ambas, sendo 0,83 e 0,73 respectivamente (p<0,05). Conclusão: A relação E/SRGC pico E é capaz de identificar elevação da PD2 do VE em coronariopatas com FEVE preservada, com menor desempenho que a relação E/e\'. / Introduction: Coronary artery disease (CAD) is important and prevalent manifestation of atherosclerosis. The assessment of diastolic function by mitral Doppler echocardiographic parameters has limitations in patients with CAD and preserved left ventricular ejection fraction (LVEF). Diastolic dysfunction is associated with higher incidence of unfavorable outcomes in these patients, regardless of LVEF. The increase in left ventricle end-diastolic pressure (LVEDP) is the main physiological consequence of diastolic dysfunction. The search for better ways of determining the LVEDP extended to the quantitative evaluation of cardiac mechanics with the modern echocardiographic techniques. The aim of this study is to correlate the invasive mesures of LVEDP and myocardial deformation measurements obtained by the two-dimensional speckle-tracking echocardiography in patients with coronary artery disease and preserved LVEF. Methods: 81 CAD patients (age: 61 ± 8 years) with LVEF >50%, scheduled for elective coronary angiography were evaluated, 40 of these with high LVEDP (>16 mm Hg). All subjects underwent conventional echocardiography immediately before catheterization and subsequent offline assessment with speckletracking echocardiography (STE) to obtain systolic and diastolic values of circumferential and longitudinal strain and strain rate, and rotational LV study. Diastolic variables of EST were analyzed both isolated and combined with the speed of the transmitral Doppler E wave. Results: Patients in the group with the high LVEDP (n =40) showed increased left atrial volume index (22 ± 6 mL vs 26 ± 8.26 mL p =0.04), E wave velocity (65 ± 15 cm/s vs 78 ±20 cm/s p = 0.02), E/e\' (average) ratio ( 8.14 ± 2.0 vs 11.54 ± 2.7 p = 0.03) and E/global circumferential strain rate (GCSR) peak E (39 cm vs 46 cm p <0.01). In 81 patients, Spearman\'s correlation with the invasive measurement of LVEDP was 0,56 (p =0.03) for the E/e\' ratio and 0.43 for the E/GCSR peak E (p <0.01). The area under the ROC curve was significant for both (p < 0.05): 0.83 and 0.73 respectively. Conclusion: The E/GCSR peak E ratio is able to identify elevated LVEDP in CAD patients with preserved LVEF, with less performance than the E/e\' ratio.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2016-02-04T11:32:50Z No. of bitstreams: 1 Carolina Thé Macedo Avaliação da acuracia...2015.pdf: 2036804 bytes, checksum: 926f70b1e7ec1709b317e04842607c6a (MD5) / Approved for entry into archive by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2016-02-04T11:33:56Z (GMT) No. of bitstreams: 1 Carolina Thé Macedo Avaliação da acuracia...2015.pdf: 2036804 bytes, checksum: 926f70b1e7ec1709b317e04842607c6a (MD5) / Made available in DSpace on 2016-02-04T11:33:56Z (GMT). No. of bitstreams: 1 Carolina Thé Macedo Avaliação da acuracia...2015.pdf: 2036804 bytes, checksum: 926f70b1e7ec1709b317e04842607c6a (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil / Um dos principais desafios na miocardiopatia chagásica é a detecção de alterações precoces na função ventricular esquerda. A avaliação do strain pelo speckle tracking na ecocardiografia bidimensional (2-D ST) é um novo método com aplicações em diversas doenças cardíacas, tendo sido validado para pacientes com infarto do miocárdio em comparação à ressonância magnética cardíaca (RMC). Neste estudo, avaliamos a hipótese de que o strain global longitudinal (SGL) possui um valor incremental à fração de ejeção (FE) pelo método de Simpson para predição de fibrose miocárdica na RMC, em pacientes portadores de doença de Chagas (DC). Métodos: Estudo observacional, com um total de 58 pacientes portadores de DC. Todos os pacientes foram submetidos à realização de ecocardiograma convencional e com strain pelo speckle tracking, além de RMC. Resultados: A análise da curva ROC mostrou que tanto a SGL (área sob a curva: 0,78, p = 0,001) quanto a fração de ejeção (área sob a curva: 0,82, p < 0,001) tiveram significância estatística na detecção de fibrose. Em relação á porcentagem de fibrose, uma alta correlação foi observada tanto com a FE pela ecocardiografia (r = - 0,70, p < 0,001) quanto com o SGL (r = 0,64, p < 0,001). Contudo, quando ajustado pela regressão linear múltipla, o SGL perdeu a significância estatística como preditor independente de fibrose miocárdica (p = 0.111). Conclusões: SGL não possui valor incremental em relação à FE na predição de fibrose miocárdica em pacientes portadores de DC. / One of the most challenging issues of chronic Chagas disease is to provide earlier detection of heart involvement. Two-dimensional speckle tracking (2-D ST) echocardiography, a new imaging modality with useful applications in several cardiac diseases, has been validated for subjects with myocardial infarction against cardiac magnetic resonance (CMR). Here we hypothesize that the longitudinal global strain (LGS) has an incremental value to ejection fraction for predicting myocardial fibrosis in subjects with Chagas disease. Methods: This observational study comprised 58 subjects with Chagas disease, confirmed by two positive serologic tests. All subjects underwent conventional Doppler echocardiogram plus speckle tracking strain, and cardiac magnetic resonance. Results: The ROC curve analysis revealed that both LGS (Area under the curve: 0.78, p = 0.001) and ejection fraction (Area under the curve: 0.82, p < 0.001) were significant predictors of myocardial fibrosis. Regarding the percentage of fibrosis, a high correlation was observed with both ejection fraction assessed by echocardiography (r = - 0.70, p < 0.001) and LGS (r = 0.64, p < 0.001). However, when adjusted through multiple linear regression, the LGS lost statistical significance as a predictor of myocardial fibrosis (p = 0.111). Conclusions: LGS has no incremental value to conventional ejection fraction measurement in the prediction of myocardial fibrosis in subjects with Chagas disease.

Cette thèse présente des travaux de recherche de métrologie en ligne de faisceaux de rayons X dans les installations synchrotrons. Deux approches principales ont été étudiées pour extraire la phase d'un front d'onde X : les méthodes utilisant des réseaux optiques et celles utilisant l'effet speckle dans le domaine X. L'interféromètre à réseaux X est l'outil le plus répandu résentatif de la première catégorie. Ses performances et son potentiel furent étudiés dans diverses situations de métrologie en ligne. Les méthodes utilisant le speckle X sont des techniques originales développées au cours de ce projet. Elles utilisent des membranes faites de petits grains diffusants, dont seule la distribution statistique est connue, pour permettre la modulation du front d'onde. Les différentes techniques furent déployées expérimentalement sur les lignes de lumière BM05 de l'ESRF et B16 de Diamond Light Source. Leurs implémentations servirent à la caractérisation de différents composants optiques utilisés pour manipuler les faisceaux synchrotron X et à l'étude de la faisabilité de micro imagerie par contraste de phase avec les sus citées techniques. / This thesis presents research and development work on synchrotron X-ray at-wavelength metrology methods. Two approaches for measuring the phase of an X-ray wavefront were studied: the grating-based and the speckle-based methods. The X-ray grating interferometer is the most widespread technique representative of the first category. Its performance and potential in various situations encountered in at-wavelength metrology was investigated. Speckle methods are X-ray phase sensing techniques newly developed during this thesis project. They make use of membranes with small statistical features to modulate the beam wavefront. The different methods were deployed experimentally at the beamlines BM05 of the ESRF and B16 of the Diamond Light Source. Their implementation permitted the characterization of various kinds of optical elements used to manipulate synchrotron X-ray beamsas well as the feasibility study of micro phase contrast imaging using the two methods described above.

Medical ultrasound is one of the most used tools for obtaining diagnostic, being a noninvasive technique, with high efficiency, low cost and real-time visualization. But these images are usually contaminated with a type of multiplicative noise known as speckle noise. This noise superimposed on the image granules that distorts and complicates the analysis of the diagnosis. Despite the removal of multiplicative noises has not been studied so extensively as the elimination of additive noise, there are some works that propose solutions to eliminate this type of noise, including works using variational methods. The variational methods have a smoothing term and a fidelity term, which are responsible for smoothing and preserving image characteristics, respectively. Typically, a balance is made between these two terms that will be used for all pixels in the image. This report will propose a variational method in order to reduce speckle noise in ultrasound images. The differential of the proposed method over other methods is the inclusion of a function in order to detect the locations of pixels with high noise level and pixels containing edges, ie, important features of the image that should be preserved. The function will adjust the fidelity and smoothing of the functional, so that this balance causes smoothing to be more severe in very noisy pixels and fidelity is more intense at the image edges. / Ultrassonografia médica é uma das ferramentas mais utilizadas para obtenção de diagnósticos, por ser uma técnica não invasiva, com alta eficácia, baixo custo e visualização em tempo real. Porém essas imagens normalmente são contaminadas com um tipo de ruído multiplicativo, conhecido como ruído speckle. Esse ruído sobrepõe granulações na imagem de forma que a distorce e dificulta a análise do diagnóstico. Apesar da eliminação de ruídos multiplicativos não ter sido estudada de forma tão extensiva quanto a eliminação de ruídos aditivos, existem alguns trabalhos que propõem soluções para eliminação deste tipo de ruído, incluindo trabalhos que usam de métodos variacionais. Os métodos variacionais possuem um termo de suavização e um termo de fidelidade, que são responsáveis por suavizar e preservar características da imagem, respectivamente. Normalmente, é feito um balanceamento entre esses dois termos que será utilizado em todos os pixels da imagem. Neste trabalho será proposto um método variacional com o objetivo de reduzir ruídos speckle em imagens de ultrassonografia. O diferencial do método proposto em relação a outros métodos, é a inclusão de uma função com o objetivo de detectar as localizações dos pixels com alto nível de ruído e dos pixels que contenham bordas, ou seja, características importantes da imagem que devem ser preservadas. Assim, a função irá ajustar a fidelidade e suavização do funcional, de forma que este balanceamento faça com que a suavização seja mais intensa em pixels bastante ruidosos e a fidelidade seja mais intensa em bordas da imagem. / Mestre em Ciência da Computação

A cimentação de próteses e/ou de outros elementos protéticos constituem-se em uma preocupação permanente, já que uma das grandes aplicações do cimento de fosfato de zinco é como agente cimentante. No entanto, a reação de presa do cimento de fosfato de zinco, assim como o tempo de sua presa final, não estão ainda completamente esclarecidos. O presente estudo visa analisar, microestruturalmente, a evolução da reação de presa do cimento de fosfato de zinco. Mais especificamente, buscou-se mensurar, baseado no fenômeno conhecido como speckle dinâmico, o tempo de duração da reação de presa do cimento de fosfato de zinco, desde o momento do término da espatulação até a sua presa completa, em ambiente com temperatura e umidade relativa do ar controlada. A metodologia utilizada consiste na análise do speckle dinâmico obtido através da luz laser, em um ensaio não-destrutivo. A partir dos dados coletados pela técnica óptica de speckle, usando algoritmos computacionais, foi possível estabelecer os coeficientes de correlação temporal e momentos de intensidade. O tratamento estatístico permitiu relacionar e comparar com outros parâmetros tradicionais, químicos e mecânicos macroestruturais já existentes e estudados por outros autores. Pode-se concluir que os resultados alcançados pela nova técnica e pelos métodos convencionais são convergentes. / The prosthesis cementation and/or other prosthetic elements, consists in permanent concern, since one of the major applications of zinc phosphate cement is as lutting agent. This study aims at the microstructural analyze to the evolution of the zinc phosphate cement´s setting reaction. More specifically, searched to verify, based on the known phenomenon as dynamic speckle, how long takes the setting reaction of zinc phosphate cement, since the moment of the ending of the mix until your complete setting, in environment with air relative humidity and temperature controlled. The used methodology consist in the analysis of dynamic speckle gotten through the laser, in a non-destructive assay. From the data supplied by the laser speckle, it was possible to establish the temporal correlation coefficients and intensity moments. The statistical treatment, allowed to compare and relate with other traditional, chemical and mechanical macrostructural parameters, already existing and studied by other authors. It can be conclude that outcomes achieved by the new technique and with the conventional methods are convergent.

Desde o primeiro relato a Doença de Chagas permanece endêmica na América Latina com 18 milhões de pessoas cronicamente infectadas e, aproximadamente, 200.000 novos casos por ano. Doença parasitária causada por Trypanosoma cruzi, tem como transmissor \"natural\" da doença um inseto hematófago, o Reduris (barbeiro). Este inseto se torna infectado ao ingerir o sangue de um animal ou indivíduo infectado com o Trypanosoma cruzi. O contágio ocorre basicamente nas áreas rurais nas quais o homem, frequentemente, está em contato com hospedeiros e vetores ao destruir a mata nativa. Apesar da infecção geralmente ocorrer nos primeiros anos de vida, os pacientes infectados podem manifestar os sinais e sintomas da cardiopatia chagásica até 20 anos mais tarde. O custo propriamente dito e o sofrimento humano representados pela Doença de Chagas são grandes. Medicamentos, internações hospitalares frequentes e tratamento com dispositivos de alto custo (ex: marcapasso/ cardiodesfibrilador). Com quadro clínico insidioso, os pacientes podem apresentar insuficiência cardíaca franca, eventos tromboembólicos, arritmias ventriculares, dor torácica atípica e morte súbita. Seu diagnóstico baseia-se em epidemiologia positiva, anamnese, exame físico, alterações eletrocardiográficas, radiológicas e testes sorológicos. O envolvimento cardíaco é a principal causa de morte, sendo que a fisiopatologia e a evolução clínica da doença não são completamente compreendidas e a estratificação de risco permanece um desafio. A presença de disfunção miocárdica associada ou não à doença arterial aterosclerótica vem acompanhada de áreas de fibrose miocárdica e tem se mostrado como importante fator de pior prognóstico. A Ressonância Magnética Cardíaca (RMC) é um método já consagrado na detecção de fibrose miocárdica pela técnica de realce tardio (RT). Os objetivos dessa tese são: 1-Correlacionar o strain miocárdico nos segmentos do ventrículo esquerdo com as áreas de realce tardio detectadas na Ressonância Magnética Cardíaca, 2- Correlacionar o strain global do ventrículo esquerdo avaliado pela técnica de Speckle Tracking com a extensão de fibrose (numero de segmentos) avaliada pela Ressonância Magnética Cardíaca; 3- Comparar a Fração de ejeção avaliada pelo Ecocardiograma bidimensional e a Ressonância Magnética Cardíaca em pacientes com cardiopatia chagásica crônica; 4- Avaliar se existe relação entre a fração de ejeção avaliada pelo ecocardiograma bidimensional e a extensão de fibrose (número de segmentos) pela Ressonância Cardíaca. Foram selecionados 31 pacientes com o diagnóstico confirmado de Doença de Chagas. 27 pacientes que respeitaram os critérios de inclusão e exclusão, e que assinaram o termo de consentimento livre e esclarecido realizaram Ressonância Magnética Cardíaca com a técnica de realce tardio. De todos os pacientes selecionados, 27 completaram o protocolo da RMC e realizaram em sequencia o Ecocardiograma transtorácico para avaliar o strain miocárdico (speckle tracking) em intervalo máximo de 5 dias. Todos que completaram o protocolo não apresentaram efeitos adversos e os exames foram considerados interpretáveis. Para calcular a amostra de pacientes necessária, os cálculos foram feitos pela estatística de teste t, com distribuição t de Student, para comparação entre duas médias, com poder de teste de 80% e nível de significância de 5%, o que resultou numa estimativa de tamanho mínimo de amostra de 22 lesões por grupo (44 lesões) para que seja possível identificar diferenças significativas em todas as regiões numa amostra com medidas de mesmo comportamento que as observadas em Yajima et al e Jitsuo Higaki et al. Com isso, a amostra mínima seria de 22 pacientes. Para avaliar a concordância entre variáveis quantitativas, utilizou-se o coeficiente de concordância de Lin com intervalo de confiança (IC) 95% estimado segundo método Bootstrap. O coeficiente de concordância de Lin (Rc) combinada precisão e acurácia para determinar se observações desviam-se significativamente da linha de perfeita concordância (linha de 45 graus com origem no 0 dos eixos x e y). O coeficiente de Kappa de Cohen com IC 95% foi utilizado em analises de concordância para variáveis categóricas. Valores de p foram calculados utilizando-se método exato. Os critérios de Landis & Koch foram utilizados na interpretação dos coeficientes de concordância, assim definidos: (a) quase-perfeita, para valores de 0,81 a 1,00; (b) substancial, para valores de 0,61 a 0,80; (c) moderada, para valores entre 0,41 e 0,60; (d) regular, para valores entre 0,21 e 0,40; (d) discreta, para valores de 0 a 0,20. As estimações de intervalos de confiança 95% via bootstrap basearam-se em 1000 replicações. Estimativas de sensibilidade, especificidade, valores preditivo positivo e negativo com IC95% foram determinados. Variáveis quantitativas foram comparadas entre 2 grupos independentes utilizando-se testes não-paramétrico de Mann-Whitney com métodos exatos de cálculo do valor-p. Variáveis quantitativas comparadas com Mann-Whitney foram descritas com mediana e intervalo interquartil. Dado o reduzido tamanho de amostra, analise de regressão logística binaria univariada foi conduzida utilizando método exato. Para covariável quantitativa foi testada, a suposição de linearidade com o log-odds no modelo de regressão logística através da construção de \"Smoothed Scatter Plots\". Quando suposição não foi satisfeita, covariável originalmente quantitativa foi dicotomizadas segundo a mediana da distribuição. Odds ratios e seus respectivos intervalos de confiança 95% foram estimados. Analises de correlação entre variáveis quantitativas foram conduzidas utilizando-se coeficiente de correlação de Spearman(rho)(com IC95%). Forte correlação foi definida como |rho| >=0.70; correlação moderada para 0.5 <= |rho| <0.7 ; correlação fraca a moderada para 0.3<= |rho| <0.5; e fraca para |rho| <0.3. Normalidade foi avaliada com a inspeção visual de histogramas e aplicação do teste de normalidade Shapiro-Wilks. Todos os valores de p apresentados são do tipo bilateral: p < 0.05 e 0.05<p<= 0.10 foram considerados significantes e marginalmente significantes respectivamente. O software R (R Foundation, Vienna, Austria) foi utilizado na análise estatística de dados. Resultados: Dos 27 pacientes do estudo temos a idade média dos pacientes de 53,1 +- 7,0 anos, com mediana de 54 anos, sendo 08 (29,7%) homens e 19 (70,3%) mulheres. A fração de ejeção média pelo ecocardiograma foi de 55,1 +- 14,7%, e pela Ressonância Magnética Cardíaca foi de 55,8 +- 13,4%. O número total de segmentos avaliados foi 453 (98,7%), com interpretação não realizada em apenas 6 segmentos (1,3%) pelo ecocardiograma, de um total de 459. Encontramos realce tardio em 61 segmentos analisados e do total, 86 segmentos apresentaram alteração do strain. Tendo como padrão ouro o realce tardio na RMC, comparamos segmento a segmento o resultado entre essa e o ecocardiograma (speckle tracking). Levamos em conta a literatura que descreve uma prevalência da fibrose em portadores de cardiopatia chagásica crônica de aproximadamente 40%. Com esses dados obtivemos uma sensibilidade de 95%, especificidade de 91%, Valor preditivo positivo de 88,6% e valor preditivo negativo de 96,6%. Correlacionando o Strain Global Longitudinal (SGL) e a extensão (número de segmentos com realce tardio pela RMC) da fibrose neste trabalho, não observou-se diferença nas medianas de número de segmentos na CMR comparadas entre os grupos Strain Global Longitudinal - normal x alterado (p=0.287 , teste exato de Mann-Whitney). Utilizando como limites de fração de ejeção do ventrículo esquerdo >= 55% como normal e <55% alterada, comparamos à extensão de fibrose- numero de segmentos- ( realce tardio) pela CMR. Observou-se uma diferença marginalmente significativa na comparação das medianas do numero de segmentos com realce tardio na CMR entre os 2 grupos (p=0.064). ¹based on exact Mann-Whitney test. Comparamos também a fração de ejeção do ventrículo esquerdo pela RMC e pelo Ecocardiograma transtorácico utilizando o método de Simpson. Ao nível de significância de 5% (coeficiente de Lin), observou-se uma quase perfeita concordância entre FEVE pela Ressonância Magnética Cardíaca e FEVE pelo Ecocardiograma transtorácico utilizando em ambos o método de Simpson. (Rc = 0.9335 IC95% 0.878-0.957; N=27). / Since the first report, Chaga\'s disease remains endemic in Latin America with 18 million chronically infected people and approximately 200,000 new cases per year. Parasitic disease caused by Trypanosoma cruzi, is \"natural\" transmitter disease of a hematophagous insect, the Reduris (barber). This insect becomes infected by ingesting blood of an animal or individual infected with Trypanosoma cruzi. The infection occurs primarily in rural areas where men often are in touch with hosts and vectors by destroying the native forest. Despite the infection usually occurs early in life, infected patients may exhibit signs and symptoms of Chagas disease 20 years later. The cost itself and human suffering represented by Chagas disease are a public issue. Medication, frequent hospitalization and treatment with costly devices (eg pacemaker / defibrillator) are frequently necessary. With insidious clinical signs and symptons, patients may present with heart failure, thromboembolic events, ventricular arrhythmias, atypical chest pain and sudden death. Its diagnosis is based on positive epidemiology, history, physical examination, electrocardiographic, radiological and serological changes. Cardiac involvement is the leading cause of death, and the pathophysiology and clinical course of the disease are not fully understood and the risk stratification remains a challenge. The presence of myocardial dysfunction with or without atherosclerotic arterial disease is accompanied by myocardial fibrosis areas and has been an important factor of poor prognosis. Cardiac Magnetic Resonance (CMR) is a method already established in the detection of myocardial fibrosis by delayed gadolinium enhancement technique (DGE). The objectives of this thesis are: 1-To correlate myocardial strain in left ventricular segments with areas of late enhancement detected in Cardiac Magnetic Resonance, 2- correlate the global left ventricular strain measured by Speckle Tracking technique with fibrosis extension (number of segments) evaluated by Cardiac Magnetic Resonance; 3- Compare the ejection fraction assessed by Two-dimensional echocardiography and cardiac Magnetic Resonance in patients with chronic cardiac Chagas\' disease; 4- To assess whether there is a relationship between the ejection fraction assessed by two-dimensional echocardiography and fibrosis extension (number of segments) by CMR. We selected 31 patients with confirmed diagnosis of Chagas\' disease. 27 patients who complied with the inclusion and exclusion criteria, and who signed the informed consent , performed Cardiac Magnetic Resonance with late gadolinium enhancement (DGE) technique. Of all the selected patients, 27 completed the RMC protocol and were in sequence directed to the transthoracic echocardiogram to assess myocardial strain (speckle tracking) in maximum interval of 5 days. Everyone who completed the protocol showed no adverse effects and the tests were considered interpretable. To calculate the sample required patients, we used the test statistic t, with t Student distribution for comparison between two averages, with the power to test 80% and 5% significance level, which resulted in an estimate minimum sample of 22 injuries per group size (44 injuries) so you can identify significant differences in all regions in a sample with the same measures of behavior than those observed in Yajima et al and Jitsuo Higaki et al. Thus, the minimum sample size would be 22 patients. To evaluate the correlation between quantitative variables, we used the Lin\'s concordance coefficient (1,2) with a confidence interval (CI) 95% estimated second method Bootstrap (4). The correlation coefficient Lin (Rc) combines precision and accuracy to determine if observations deviate significantly from perfect correlation line (45 degree line with origin 0 of the x and y axes). Cohen\'s kappa coefficient with 95% (3) was used for analysis of agreement for categorical variables. P values were calculated using the exact method. The Landis and Koch criteria (5) were used in the interpretation of correlation coefficients defined as follows: (a) quasi-perfect for values 0.81 to 1.00; (b) substantial amounts of 0.61 to the 0.80; (c) Moderate to values between 0.41 and 0.60; (d) regular, to between 0.21 and 0.40; (d) mild to values from 0 to 0.20. The estimation of 95% confidence intervals by bootstrap based on 1000 replicates. Quantitative variables were compared between two independent groups using non-parametric Mann-Whitney test with exact methods of calculating the p-value. (6-8) Quantitative variables compared with Mann-Whitney were described as median and interquartile range. Given the small sample size, regression analysis univariate binary logistic regression was conducted using exact method (9-11). For quantitative covariate was tested, the linearity assumption with the log-odds in the logistic regression model by building \"Smoothed Scatter Plots\". (9) When assumption was not met, originally quantitative covariate was dichotomized according to the median of the distribution. Odds ratios and their 95% confidence intervals were estimated. All significance probabilities (p values) presented are the bilateral type and values less than 0.05 considered statistically significant. The R (R Foundation, Vienna, Austria) software was used for statistical analysis of data. In order to measure the correlation between the results of both tests in the study were calculated sensitivity, specificity, positive predictive value and negative predictive value considering the CMR as the gold standard. Results: Of the 27 study patients have a average age of 53.1 + - 7.0 years and median of 54 years. 08 (29.7%) men and 19 (70.3%) women. The average ejection fraction by echocardiography was 55.1 + - 14.7%, and by Cardiac Magnetic Resonance was 55.8 + - 13.4%. The total number of evaluated segments was 453 (98.7%), with no interpretation performed in only 6 segments (1.3%) on echocardiography, a total of 459 segments. Delayed enhancement by Cardiac Magnetic Ressonance was found in 61 segments analyzed. In the order \"side\" 86 segmets registered an altered strain. As the gold standard the delayed enhancement in the MRC, compared to segment studied segment. We take into account the literature describing the prevalence of fibrosis in patients with chronic Chagas\' heart disease of approximately 40%. With this data we obtained a sensitivity of 95%, specificity 91%, positive predictive value of 88.6% and a negative predictive value of 96.6%. Correlating the Global Longitudinal Strain (SGL) and extent (number of segments with delayed enhancement by CMR) of fibrosis in this study, no difference was observed in the number of segments of medians in the CMR compared between Strain Global Longitudinal groups - Normal x changed (p = 0.287, exact Mann-Whitney). Using as an ejection fraction of the left ventricle limits > = 55% as normal and < 55% changed, compared to the extent of fibrose- number of segments- (delayed enhancement) by CMR. There was a marginally significant difference when comparing the median number of segments with delayed enhancement on CMR between the 2 groups (p = 0.064). ¹based on exact Mann-Whitney test. We also compared the ejection fraction of the left ventricle by CMR and transthoracic echocardiography using the Simpson method. At a significance level of 5% (Lin coefficient), there was an almost perfect correlation between LVEF by Cardiac Magnetic Resonance and LVEF by using transthoracic echocardiography in both the Simpson method. (Rc = 0.9335 95% CI 0878-0957; N = 27)

A doença arterial coronária é importante e prevalente manifestação da aterosclerose. A avaliação da função diastólica pelos parâmetros mitrais obtidos com Doppler ecocardiográfico possui limitações nos coronariopatas com fração de ejeção do ventrículo esquerdo (FEVE) preservada. Nestes, a disfunção diastólica, independentemente da FEVE, associa-se a maior incidência de desfechos desfavoráveis. A elevação da pressão diastólica final (PD2) do ventrículo esquerdo (VE) é a principal consequência fisiológica da disfunção diastólica. A pesquisa por melhores formas de determinação da PD2 do VE estendeu-se às modernas técnicas ecocardiográficas de quantificação da mecânica cardíaca. O objetivo deste estudo é correlacionar as medidas de deformação miocárdica, obtidas pelo speckle-tracking ecocardiográfico bidimensional, com a medida invasiva da PD2 do VE em pacientes com insuficiência coronariana e FEVE preservada. Métodos: foram avaliados 81 coronariopatas (idade: 61 ±8 anos) com FEVE >50%, encaminhados para cineangiocoronariografia eletiva, 40 destes com PD2 elevada (>16 mm Hg). Todos os indivíduos foram submetidos à avaliação ecocardiográfica convencional imediatamente antes do cateterismo e subsequente avaliação offline, com ecocardiografia speckle tracking (EST) para obtenção de medidas sistólicas e diastólicas de strain e strain rate circunferenciais e longitudinais, e estudo rotacional do VE. Foram analisadas as variáveis diastólicas da EST, tanto de forma isolada, quanto combinada com a velocidade da onda E ao Doppler. Resultados: Comparativamente, os pacientes do grupo com PD2 do VE elevada (n=40) mostraram aumento do volume indexado do átrio esquerdo (22 ±6 mL vs 26 ±8,26 mL p=0,04), velocidade da onda E (65 ±15 cm/s vs 78 ±20 cm/s p=0,02), relação E/e\' médio (8,14 ±2,0 vs 11,54 ±2,7 p=0,03) e relação E/strain rate global circunferencial (SRGC) pico E (39 cm vs 46 cm p <0,01). Nos 81 pacientes a correlação de Spearman com a medida invasiva da PD2 do VE foi de 0,56 para a relação E/e\' (p=0,03) e de 0,43 para a relação E/ESRGC pico E (p<0,01). A área sob a curva ROC foi significativa em ambas, sendo 0,83 e 0,73 respectivamente (p<0,05). Conclusão: A relação E/SRGC pico E é capaz de identificar elevação da PD2 do VE em coronariopatas com FEVE preservada, com menor desempenho que a relação E/e\'. / Introduction: Coronary artery disease (CAD) is important and prevalent manifestation of atherosclerosis. The assessment of diastolic function by mitral Doppler echocardiographic parameters has limitations in patients with CAD and preserved left ventricular ejection fraction (LVEF). Diastolic dysfunction is associated with higher incidence of unfavorable outcomes in these patients, regardless of LVEF. The increase in left ventricle end-diastolic pressure (LVEDP) is the main physiological consequence of diastolic dysfunction. The search for better ways of determining the LVEDP extended to the quantitative evaluation of cardiac mechanics with the modern echocardiographic techniques. The aim of this study is to correlate the invasive mesures of LVEDP and myocardial deformation measurements obtained by the two-dimensional speckle-tracking echocardiography in patients with coronary artery disease and preserved LVEF. Methods: 81 CAD patients (age: 61 ± 8 years) with LVEF >50%, scheduled for elective coronary angiography were evaluated, 40 of these with high LVEDP (>16 mm Hg). All subjects underwent conventional echocardiography immediately before catheterization and subsequent offline assessment with speckletracking echocardiography (STE) to obtain systolic and diastolic values of circumferential and longitudinal strain and strain rate, and rotational LV study. Diastolic variables of EST were analyzed both isolated and combined with the speed of the transmitral Doppler E wave. Results: Patients in the group with the high LVEDP (n =40) showed increased left atrial volume index (22 ± 6 mL vs 26 ± 8.26 mL p =0.04), E wave velocity (65 ± 15 cm/s vs 78 ±20 cm/s p = 0.02), E/e\' (average) ratio ( 8.14 ± 2.0 vs 11.54 ± 2.7 p = 0.03) and E/global circumferential strain rate (GCSR) peak E (39 cm vs 46 cm p <0.01). In 81 patients, Spearman\'s correlation with the invasive measurement of LVEDP was 0,56 (p =0.03) for the E/e\' ratio and 0.43 for the E/GCSR peak E (p <0.01). The area under the ROC curve was significant for both (p < 0.05): 0.83 and 0.73 respectively. Conclusion: The E/GCSR peak E ratio is able to identify elevated LVEDP in CAD patients with preserved LVEF, with less performance than the E/e\' ratio.

La performance des cibles du Laser LMJ est très sensible à l'uniformité de la tache focale du laser. La technique utilisée à ce jour pour éviter les inhomogénéités est de rendre le faisceau partiellement incohérent, ce qui a pour conséquence la fluctuation de points chauds (speckles) au cours du temps, avec un effet de moyenne. De nombreux travaux ont d'ores et déjà été menés concernant l'étude de ces points chauds dans le cadre d'un faisceau unique au plan focal. Dans cette thèse, on s'intéresse à ces points chauds lorsqu'il sont issus de la superposition de faisceaux multiples, et plus particulièrement aux points chauds dans le cas de la configuration du LMJ. On a établi une équation analytique permettant de calculer la taille des points chauds dans le cas d'un speckle généré par des faisceaux multiples. Cette formule est en parfait accord avec les différents résultats obtenus par simulations numériques grâce au code PARAX. On a ainsi pu prédire la taille du grain de speckle LMJ en fonction de différentes configurations LMJ telle qu'une configuration à deux ou trois cônes et pour des choix de polarisations différents. Il en ressort que l'impact de la polarisation est assez faible sur les caractéristiques du speckle LMJ. Toutefois la double polarisation est la plus adaptée aux critères d'uniformité requis pour une bonne interaction laser-plasma. D'autre part on a montré que les grains de speckle LMJ sont de l'ordre de la longueur d'onde.Dans la seconde partie de cette thèse, on a établi les formules des contraste, temps de vie, trajectoires et vitesses des points chauds deux techniques de lissage : Lissage par Dispersion Spectrale Transverse (LDST) et Longitudinal (LDSL). Ces derniers sont respectivement utilisés sur le NIF et prochainement sur le LMJ. On a ainsi montré que quels que soient le nombre de cône et le choix des polarisations faites sur le LMJ, la durée de vie d'un point chaud LMJ est environ de 2 ps et le contraste intégré sur des temps infinis est approximativement de 15%. Les vitesses sont également très faibles (10-6c) et faiblement influencées par le choix des polarisations. / The future French Laser Megajoule (LMJ) is a multiple laser beam facility built to achieve Inertial confinement Fusion (ICF). It is mainly designed for an indirect drive scheme using X-rays conversion. In this scheme, the target in the center of the hohlraum is irradiated and then compressed by the X-rays more uniformly than what it would be in a direct drive schemes. However, a high of uniformity is still needed to reach ignition since the propagation of intense laser beams in an under-critical plasma can generate laser-plasma instabilities (LPI). The control of LPI is of crucial importance for the success of ICF. By breaking both spatial and temporal coherences, the use of optical smoothing techniques, such as smoothing by spectral dispersion (SSD), often dramatically reduces LPI and also ensures the reproducibility of laser conditions from one shot to another. An accurate description of the speckle pattern in the hohlraum is thus of great interest for ICF experiments.We focus our attention on the spatial and then temporal properties of the speckles pattern generated by multiple laser beams. At first, we establish equations for the 3D speckle size based on autocorrelation functions. Numerical simulations of the propagation of multiple laser beams in vacuum are then performed with the PARAX code in configurations where the paraxial approximation can be used. The case of speckle patterns in the LMJ configuration in the zone where all the beams overlap is eventually studied. We show that such speckles have an ellipsoidal shape. Finally, influence of the polarization of the beams on the shape, size and abundance of the speckles is also investigated. In a second part we study the important aspect of temporal smoothing techniques like the movement of the speckles. This work is also triggered by the development of a statistical model that describes the motion of hot spots in order to evaluate the contrast, the trajectory and the velocity of LMJ hot spots. We address these quantities in the case of a speckle pattern generated by multiple laser beams thanks to the autocorrelation function in intensity.