L’appendicite aiguë est la pathologie abdominale aiguë courante et la plus fréquente parmi celles qui nécessitent une intervention chirurgicale rapide. L’imagerie occupe une place croissante dans son diagnostic parce qu’elle tente d’éviter simultanément les appendicectomies inutiles et les perforations appendiculaires compliquées de péritonite tout en recherchant des pathologies alternatives. Si plusieurs techniques d’imagerie sont disponibles – dont la radiographie sans préparation de l’abdomen (dont la performance est faible) et l’imagerie par résonance magnétique (peu disponible, en particulier en urgence) – l’ultrasonographie (US) et la tomodensitométrie (TDM) occupent des positions centrales. Nos études ont investigué la performance de ces dernières, en considérant notamment la réduction de la dose d’irradiation et le recours aux contrastes artificiels. En effet, l’irradiation liée à l’usage de la TDM est à considérer puisque les patients souffrant d’appendicite aiguë sont jeunes (en moyenne 30 ans) tout comme le recours aux contrastes associé à des coûts, de l’inconfort et des risques. Enfin, la performance de ces techniques étant susceptibles d’être influencée par la corpulence des patients et leur quantité de graisse intra-abdominale, l’influence de ces paramètres sur la performance a été évaluée.<p><p>A travers quatre études, nous avons montré que l’US et la TDM sans contraste IV ou entérique ont des performances similaires quant au diagnostic d’appendicite aiguë et de pathologies alternatives, indépendamment de l’expérience du radiologue et de la corpulence du patient. Néanmoins, les examens non concluants (sans diagnostic d’appendicite aiguë ni de pathologie alternative mais où l’appendice n’est pas vu) sont plus fréquents en US qu’en TDM. L’appendice normal, dont la visualisation permet d’exclure le diagnostic d’appendicite aiguë, est plus fréquemment visible en TDM qu’en US, mais en TDM la reproductibilité quant à considérer la même structure comme étant l’appendice dépend du lecteur. L’injection IV de contraste iodé n’augmente pas la proportion d’appendices détectés mais la reproductibilité d’un lecteur particulier. Aucune caractéristique du sujet ni de son appendice, y compris son environnement abdominal, ne permet de prédire cette reproductibilité. La performance de la TDM est constante quelle que soit la dose d’irradiation ou le recours au contraste IV et/ou entérique, indépendamment de la corpulence du patient. La hiérarchie de l’information apportée par les signes évocateurs d’appendicite aiguë n’est pas influencée par la dose; l’infiltration de la graisse péri-appendiculaire et le diamètre appendiculaire en étant les signes les plus prédictifs, malgré le moindre rapport signal/bruit de l’image générée à faible dose. La fréquence de visualisation de l’appendice est aussi indépendante de cette dose. L’exactitude du diagnostic dépend principalement du lecteur mais pas du contraste – quelle qu’en soit la voie d’administration (orale ou IV) – ni de la dose d’irradiation. Le genre du patient influence cependant cette exactitude, le diagnostic étant plus fréquemment correct chez l’homme que chez la femme, en particulier dans les pathologies alternatives.<p><p>En conclusion, comme les techniques US et TDM que nous avons investiguées ont des performances équivalentes, les risques associés à l’irradiation et au contraste doivent intervenir dans leur choix. L’US, utilisée en première intention, devrait être complétée par la TDM si son résultat n’est pas concluant. Dans ce cas, la TDM devrait être réalisée, toujours à basse dose d’irradiation, d’abord sans puis, si nécessaire, avec contraste IV et/ou oral.<p> / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished

A pesquisa buscou avaliar se a ultrassonografia portátil, durante consulta clínica em uma unidade básica de saúde pública do Sistema Único de Saúde brasileiro, foi capaz de fornecer informações adicionais confiáveis para a tomada de decisões terapêuticas e diminuir o tempo de espera para uma eventual avaliação especializada, por meio da comparação entre os achados obtidos na ultrassonografia portátil e na ultrassonografia convencional. A ultrassonografia é o segundo método de avaliação por imagem mais utilizado na prática médica, após o Raio-X. Não emite radiações ionizantes e seu efeito sobre os tecidos biológicos é seguro, desde que em nível de intensidade acústica mínima para obtenção dos resultados desejados. Este trabalho surgiu da observação de quão prolongado é o tempo de espera por exames de ultrassom a que estão sujeitos os pacientes da saúde pública brasileira, chegando até dois anos em alguns casos, contrariando protocolos de recomendação e podendo comprometer a saúde do paciente. Avaliou-se custo-efetividade da tecnologia, suas principais limitações, a necessidade de criação de protocolos para sua utilização e os subsídios fornecidos para a tomada de decisões pelo médico clínico. A tecnologia foi aplicada em exames nas áreas de medicina interna, sistema musculoesquelético e cardiologia. Empregou aparelho de ultrassom portátil aprovado pela Anvisa, modelo Vscan™ Dualprobe. Conforme protocolos do Instituto Americano de Ultrassom em Medicina (AIUM), os sujeitos da pesquisa foram submetidos a exame com aparelho portátil, durante o momento da consulta com o pesquisador, após anamnese e exame físico. Posteriormente, foram submetidos a exame empregando aparelho convencional, com médico possuindo titulação em ultrassonografia. As imagens e os achados foram comparados entre os exames e se calculou um índice de confiabilidade Kappa global nas três áreas estudadas de 91,12%, embora o índice para a área cardíaca tenha sido de 76,92%, o que demonstra a limitação do uso do ultrassom portátil para a área. A pesquisa demonstrou que o emprego da ultrassonografia portátil pode vir a ser um importante aliado do médico clínico, permitindo melhoria da qualidade da saúde prestada aos pacientes do Sistema Único de Saúde brasileiro. / The research aimed to evaluate whether portable ultrasonography, during clinical consultation in a basic public health unit of the Brazilian Unified Health System, was able to provide reliable additional information for therapeutic decision-making and to reduce the waiting time for a specialized evaluation, by means of the comparison between the findings obtained in portable ultrasonography and conventional ultrasonography. Ultrasonography is the second method of image evaluation more used in medical practice after the X-ray. It does not emit ionizing radiation and its effect on biological tissues is safe, provided that at minimum acoustic intensity level to obtain the desired results. This study was based on the observation of the length of time the patient waits for the ultrasound exams to which Brazilian public health patients are subjected, up to two years in some cases, contrary to recommendation protocols and potentially compromising patient´s health. It evaluated the cost-effectiveness of the technology, its main limitations, the need to create protocols for its use and the subsidies provided for the decision-making by the clinician. The technology was applied in examinations in the areas of internal medicine, musculoskeletal system and cardiology. It was used a portable ultrasound device approved by Anvisa, model Vscan™ Dualprobe. According to protocols of the American Institute of Ultrasound in Medicine (AIUM), the subjects were examined with a portable device, during the moment of the consultation with the researcher, after anamnesis and physical examination. Subsequently, they were submitted to an examination using a conventional device, with a doctor having ultrasound titration. The images and findings were compared between the exams and a global Kappa reliability index was calculated in the three studied areas of 91.12%, although the index for the cardiac area was 76.92%, which demonstrates the limitation of the use of portable ultrasound for the area. The research demonstrated that the use of portable ultrasonography can be an important ally of the clinician, allowing an improvement in the quality of health provided to patients of the Brazilian Unified Health System.

The purpose of this hermeneutic phenomenological study was to understand the essence of the lived experience of women after having an abnormal prenatal ultrasound. One hundred years ago, health disciplines had limited therapies for prenatal and neonatal disorders. During this period, the eugenics movement influenced leaders to involuntarily sterilize individuals who were sought to be "unfit" to prevent disorders in offspring. ... One of these contemporary reproductive genetic technologies is the use of ultrasound and serum bio-medical markers for detection of congenital, chromosome, and genetic disorders. When ultrasounds reveal abnormal findings, the perceived perfect pregnancy vanishes and gives way to feelings of shock, disbelief, fear, guilt, loss, and threats to self and their unborn baby. Twelve women who had an abnormal ultrasound were interviewed within the context of their cultural values and beliefs. The method of van Manen's hermeneutic phenomenology illuminated the meaning for these women in their life worlds. ... They endured this experience through their own coping mechanisms, but often felt uncertainty and emotional turmoil until the birth. The women also sought comfort through their cultural values, beliefs, and traditions. In coping with the risks found on this abnormal ultrasound, women often selected silence or blocking perceived threats. With these coping methods, they were alone in their suffering. ... Health providers, in not recognizing these women's misunderstandings and emotional fears, abandoned them in their psychosocial and cultural needs. The significance reveals that nurses and health providers need to infuse human caring ways of being, knowing, and doing within advanced technological environments. / by Jeanne Chatham Gottlieb. / Thesis (Ph.D.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Ultrasonic guided wave imaging methods offer a cost-effective mechanism to perform in situ structural health monitoring (SHM) of large plate-like structures, such as commercial aircraft skins, ship hulls, storage tanks, and civil structures. However, current limits in imaging quality, environmental sensitivities, and implementation costs, among other things, are preventing widespread commercial adoption. The research presented here significantly advances state of the art guided wave imaging techniques using inexpensive, spatially distributed arrays of piezoelectric transducers. Novel adaptive imaging techniques are combined with in situ estimation and compensation of propagation parameters; e.g., dispersion curves and transducer transfer functions, to reduce sensitivity to unavoidable measurement inaccuracies and significantly improve resolution and reduce artifacts in guided wave images. The techniques can be used not only to detect and locate defects or damage, but also to characterize the type of damage. The improved ability to detect, locate, and now characterize defects or damage using a sparse array of ultrasonic transducers is intended to assist in the establishment of in situ guided wave imaging as a technically and economically viable tool for long-term monitoring of plate-like engineering structures.

Structural health monitoring (SHM) is concerned with the continuous, long-term assessment of structural integrity. One commonly investigated SHM technique uses guided ultrasonic waves, which travel through the structure and interact with damage. Measured signals are then analyzed in software for detection, estimation, and characterization of damage. One common configuration for such a system uses a spatially-distributed array of fixed piezoelectric transducers, which is inexpensive and can cover large areas. Typically, one or more sets of prerecorded baseline signals are measured when the structure is in a known state, with imaging methods operating on differences between follow-up measurements and these baselines. Presented here is a new class of SHM spatially-distributed array algorithms that rely on sparse reconstruction. For this problem, damage over a region of interest (ROI) is considered to be sparse. Two different techniques are demonstrated here. The first, which relies on sparse reconstruction, uses an a priori assumption of scattering behavior to generate a redundant dictionary where each column corresponds to a pixel in the ROI. The second method extends this concept by using multidimensional models for each pixel, with each pixel corresponding to a "block" in the dictionary matrix; this method does not require advance knowledge of scattering behavior. Analysis and experimental results presented demonstrate the validity of the sparsity assumption. Experiments show that images generated with sparse methods are superior to those created with delay-and-sum methods; the techniques here are shown to be tolerant of propagation model mismatch. The block-sparse method described here also allows the extraction of scattering patterns, which can be used for damage characterization.

Imagens térmicas, ou infravermelhas, contém somente informações funcionais do corpo e nenhuma informação anatômica. A falta de um referencial anatômico pode dificultar a inspeção visual da imagem em diagnósticos, motivo pelo qual imagens médicas funcionais são combinadas com imagens anatômicas, como no caso da fusão de imagens anatômicas de ressonância ou ultrassom com imagens funcionais de tomografia computadorizada e PET. Considerando isso, este trabalho apresenta um método para registro e fusão de imagens térmicas com imagens anatômicas, a fim de acrescentar referências anatômicas a imagens térmicas e facilitar a sua analise em diagnósticos. Devido as diferenças morfológicas entre as imagens anatômicas e funcionais a deformação de ao menos uma delas e necessária. Para isso foi adotado o método de transformação não rígida por interpolação utilizando B-splines com marcadores manualmente posicionados. Não há relatos da aplicação desta abordagem no registro e fusão de imagens térmicas em imagens de atlas anatômicos, apesar desta ser utilizada em outras áreas. Foi realizada uma serie de testes com imagens térmicas e anatômicas, essas últimas provindas de atlas anatômicos e fotografias de luz visível, de diferentes partes do corpo humano. O método apresentado e capaz de incluir informações de imagens anatômicas em imagens térmicas pelo registro e fusão destas, apresentando erros de posicionamento da ordem de 5 mm. / Thermal images, or infrared images, contain only functional information about the body, without anatomical information. The lack of an anatomical reference can compromise visual inspection. For this reason, functional medical images are combined with anatomical images, as in the case of the fusion of magnetic resonance or ultrasound anatomical images and PET functional images. Considering this, the present work presents a method for registration and fusion of thermal and anatomical images, with the purpose of providing anatomical references to thermal images and facilitate its analysis in diagnoses. Due to the morphological differences between the anatomical and functional images, it is necessary to transform at least one of them. For this purpose a method of non-rigid transformation with B-splines and manual landmarks was adopted. There are no reports of the application of this technique to thermal images and images from anatomical atlas, despite being used in other fields. Experiments were performed with thermal and anatomical images, the latter from atlas and visible light photographs, from different parts of the human body. The proposed method is capable of including information from anatomical images to thermal images through their registration and fusion, with errors in the order of 5 mm.

Imagens térmicas, ou infravermelhas, contém somente informações funcionais do corpo e nenhuma informação anatômica. A falta de um referencial anatômico pode dificultar a inspeção visual da imagem em diagnósticos, motivo pelo qual imagens médicas funcionais são combinadas com imagens anatômicas, como no caso da fusão de imagens anatômicas de ressonância ou ultrassom com imagens funcionais de tomografia computadorizada e PET. Considerando isso, este trabalho apresenta um método para registro e fusão de imagens térmicas com imagens anatômicas, a fim de acrescentar referências anatômicas a imagens térmicas e facilitar a sua analise em diagnósticos. Devido as diferenças morfológicas entre as imagens anatômicas e funcionais a deformação de ao menos uma delas e necessária. Para isso foi adotado o método de transformação não rígida por interpolação utilizando B-splines com marcadores manualmente posicionados. Não há relatos da aplicação desta abordagem no registro e fusão de imagens térmicas em imagens de atlas anatômicos, apesar desta ser utilizada em outras áreas. Foi realizada uma serie de testes com imagens térmicas e anatômicas, essas últimas provindas de atlas anatômicos e fotografias de luz visível, de diferentes partes do corpo humano. O método apresentado e capaz de incluir informações de imagens anatômicas em imagens térmicas pelo registro e fusão destas, apresentando erros de posicionamento da ordem de 5 mm. / Thermal images, or infrared images, contain only functional information about the body, without anatomical information. The lack of an anatomical reference can compromise visual inspection. For this reason, functional medical images are combined with anatomical images, as in the case of the fusion of magnetic resonance or ultrasound anatomical images and PET functional images. Considering this, the present work presents a method for registration and fusion of thermal and anatomical images, with the purpose of providing anatomical references to thermal images and facilitate its analysis in diagnoses. Due to the morphological differences between the anatomical and functional images, it is necessary to transform at least one of them. For this purpose a method of non-rigid transformation with B-splines and manual landmarks was adopted. There are no reports of the application of this technique to thermal images and images from anatomical atlas, despite being used in other fields. Experiments were performed with thermal and anatomical images, the latter from atlas and visible light photographs, from different parts of the human body. The proposed method is capable of including information from anatomical images to thermal images through their registration and fusion, with errors in the order of 5 mm.

This study aimed the study of ovarian follicular dynamics in a interovulatory period in nulliparous Santa Ines sheep carrying the polymorphism FecGE. Were used 21 sheep that previously genotyped for FecGE polymorphism by PCR-RFLP. The animals were divided into three groups (n = 7 / group) according to the genotype mutation: WW - non-mutant wild; EW . heterozygote and EE - homozygous. Follicular dynamics were monitored by ultrasound within a period interovulatory. The capture and measurement of the ovaries images were made every 24 hours until detection of estrus, being adjusted to every 12 hours until ovulation. It was found that 15 animals (71.42%) showed the emergence of three waves and six (28.58%) had four follicular waves. Don ft were influence of genotype on the selection, follicles . 2 and . 4 mm, (2,8 } 0,7) and follicular dominance, follicles > 5 mm, (0,9 } 0,1), the interovulatory period (17,5 } 0,2) and the duration of estrus (38,11 } 0,9). The largest number of ovulations was observed in homozygous sheep (2.4 } 0.2) compared to the wild type (1.7 } 0.2), however, heterozygous presenting intermediate value (1.9 } 0.1) but not differ from the others. Despite genetic groups did as not differ to the interval between the onset of estrus and ovulation (25,34 } 1,8), high individual variation was observed among sheep within each genotype. Santa Ines sheep that carriers the polymorphism FecGE express some differences in ovarian follicular dynamics in relation to non-mutants, being represented mainly by the largest number of ovulations in homozygous genetic group. / Este trabalho teve por objetivo o estudo da dinamica folicular ovariana do periodo interovulatorio em ovelhas nuliparas da raca Santa Ines portadoras do polimorfismo FecGE. Foram utilizadas 21 ovelhas previamente genotipadas para o polimorfismo FecGE por PCR-RFLP. Os animais foram divididos em tres grupos (n=7/grupo) de acordo com o genotipo relacionado a mutacao como segue: WW - selvagem nao mutante; EW - heterozigoto e; EE - homozigoto. A dinamica folicular foi acompanhada por ultrassom dentro de um periodo interovulatorio. A captura e mensuracao das imagens dos ovarios foram feitas a cada 24 horas ate a deteccao do estro, sendo ajustadas para cada 12 horas ate a ovulacao. Foi verificado que 15 animais (71,42%) apresentaram a emergencia de tres ondas e seis (28,58%) apresentaram quatro ondas de crescimento folicular. Nao houve influencia do genotipo sobre o numero de foliculos selecionados, . 2 e . 4 mm, (2,8 } 0,7) e dominantes, >5 mm, (0,9 } 0,1), o periodo interovulatorio (17,5 } 0,2) e, a duracao do estro (38,11 } 0,9). O maior numero de ovulacoes foi observado nas ovelhas homozigotas (2,4 } 0,2) em relacao as do tipo selvagem (1,7 } 0,2) sendo as heterozigotas apresentando valor intermediario (1,9 } 0,1), porem nao diferindo dos demais. Apesar dos grupos geneticos nao diferirem quanto ao intervalo entre o inicio do estro e a ovulacao (25,34 } 1,8 h), foi verificada alta variacao individual entre as ovelhas dentro de cada genotipo. Ovelhas nuliparas Santa Ines portadoras do polimorfismo FecGE expressam diferencas no tempo de sobrevivencia folicular e no diametro do foliculo ovulatorio em relacao as nao mutantes, sendo que o grupo genetico homozigoto apresenta um maior numero de ovulacoes.

La matière molle se consacre à l'étude des propriétés de fluides complexes. Ces fluides diffèrent des fluides simples à cause de l'existence d'une microstructure qui provient de l'arrangement particulier des éléments mésoscopiques constitutifs du matériau (agrégats de particules de noir de carbone, enchevêtrements de polymères, micelles de molécules tensioactives). C'est le couplage entre microstructure et déformation qui confère aux fluides complexes des comportements singuliers et qui engendre des écoulements hétérogènes. Comprendre ces états hors-équilibre et les dynamiques associées présente un intérêt à la fois industriel et fondamental. La rhéologie en cellule de Taylor-Couette est une technique très répandue pour l'étude de la déformation et de l'écoulement de fluides complexes. Cependant, cette méthode n'est pas adaptée à l'étude des écoulements hétérogènes car elle ne fournit qu'une description globale de l'écoulement. Pour pallier ce problème, une technique de vélocimétrie ultrasonore à deux dimensions a été couplée à la rhéologie classique. Cette visualisation locale nous a permis d'étudier l'instabilité inertielle de Taylor-Couette dans les fluides newtoniens, les instabilités élastiques de fluides viscoélastiques (polymères et solutions micellaires), la fluidification de fluides à seuil (gels de noir de carbone, microgels de carbopol et émulsions) et enfin la rupture de gels de protéine soumis à une contrainte de cisaillement. Tous ces exemples montrent des coexistences entre différents états induits par l'écoulement et permettent de revisiter les approches rhéologiques à partir de caractérisations locales des champs de déformation et de vitesse. / Soft matter scientists are dedicated to studying the properties of complex fluids. Complex fluids differ from simple fluids in that they possess a microstructure resulting from the particular arrangement of mesoscopic elements which constitute the material (aggregates of carbon black particles, entangled polymers, micelles of surfactant molecules, etc.). Peculiar flow behaviors in complex fluids, such as heterogeneous flows, arise from the coupling between microstructure and flow. Understanding these non-equilibrium states and the associated dynamics is both of industrial and fundamental interest. Rheology in a Taylor-Couette cell is a wide-spread technique for investigating the deformation and flow of complex fluids. However, this method is mostly blind to heterogeneous flows as it only provides a global description of the flow. To overcome this problem, an ultrasonic imaging technique has been combined with classical rheology. This local visualisation has allowed us to study the inertial Taylor-Couette instability in Newtonian fluids, elastic instabilities in viscoelastic fluids (polymers and micellar solutions), the fluidisation of yield stress fluids (carbon black gels, carbopol microgels and emulsions) and finally the failure of protein gels under stress. In all these cases we evidence a coexistence between different flow-induced states and revisit global rheological approaches through local characterizations of deformation and velocity fields.

Maternal diet can have a great impact on the health and development of the fetus. Poor fetal nutrition has been linked to the development of a set of conditions in later life, such as coronary heart disease, type 2 diabetes and hypertension, while restricted growth can result in hypogylcemia, hypocalcemia, hypothermia, polycythemia, hyperbilirubinemia and cerebral palsy. High alcohol consumption during pregnancy can result in Fetal Alcohol Syndrome, a condition that can cause growth retardation, lowered intelligence and craniofacial defects. Current biometric assessment of the fetus involves size-based measures which may not accurately portray the state of fetal development, since they cannot differentiate cases of small-but-healthy or large-but-unhealthy fetuses. This thesis aims to outline a set of more appropriate measures of accurately capturing the state of fetal development. Specifically, soft tissue area and liver volume measurement are examined, followed by facial shape characterisation. A number of tools are presented which aim to allow clinicians to achieve accurate segmentations of these landmark regions. These are modifications on the Live Wire algorithm, an interactive segmentation method in which the user places a number of anchor points and a minimum cost path is calculated between the previous anchor point and the cursor. This focuses on giving the clinician intuitive control over the exact position of the segmented contour. These modifications are FA-S Live Wire, which utilises Feature Asymmetry and a weak shape constraint, ASP Live Wire, which is a 3D expansion of Live Wire, and FA-O Live Wire, which uses Feature Asymmtery and Local Orientation to guide the segmentation process. These have been designed with each of the specific biometric landmarks in mind. Finally, a method of characterising fetal face shape is proposed, using a combination of the segmentation methods described here and a simple shape model with a parameterised b-spline meshing approach to facial surface representation.