1000 resultados para CT colonography (virtual colonoscopy)
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This poster highlights both the new functions taken on by UOC research librarians and the new skills that this professional profile requires, based on the experience of the UOC Virtual Library. By setting up a series of bibliometric units, the Library has been able to integrate itself into the University through bibliometric studies and other research support services. A group of research librarians provides support to researchers from the start of the research process to the assessment of their scientific output. They also provide support for the University's strategic decision-making through the analysis of bibliometric data.
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Presentado en la mesa redonda "Innovar en gestión de información: plataformas tecnológicas para creación de contenidos compartidos" de las XIII Jornadas Bibliotecarias de Andalucía (Granada, 5 y 6 Noviembre 2015).
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O objetivo neste artigo é apresentar uma investigação das inter-relações entre as práticas religiosas, econômicas e políticas cunhadas pela Igreja Católica na ocasião da Festa do Jubileu do Bom Jesus, na cidade mineira de Congonhas do Campo. Pretende-se compreender melhor como ocorrem manipulações simbólicas entre o sagrado e o profano no interior das organizações. Assim, a partir de um estudo no contexto da Igreja Católica, visou-se trazer novos insights ao campo dos estudos organizacionais que tratam da esfera simbólica de forma geral. Optou-se por um estudo de caso qualitativo, de cunho exploratório-descritivo usando entrevistas e observações registradas em diário de campo. As entrevistas foram feitas com moradores da cidade, comerciantes e com o padre responsável pela paróquia. Para interpretação dos dados, utilizou-se a análise do discurso, situando o discurso como manifestação objetiva de um arcabouço histórico e ideológico. Nos resultados, aponta-se para uma dualidade entre sagrado e profano, emergindo a flexibilização de concepções religiosas dominantes para absorver práticas econômicas que financiem o capital religioso da referida igreja.
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Positron emission tomography is a functional imaging technique that allows the detection of the regional metabolic rate, and is often coupled with other morphological imaging technique such as computed tomography. The rationale for its use is based on the clearly demonstrated fact that functional changes in tumor processes happen before morphological changes. Its introduction to the clinical practice added a new dimension in conventional imaging techniques. This review presents the current and proposed indications of the use of positron emission/computed tomography for prostate, bladder and testes, and the potential role of this exam in radiotherapy planning.
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RESUMOO objetivo neste trabalho é analisar se os Fundos Setoriais redefiniram o modelo de promoção de Ciência, Tecnologia e Inovação (CT&I), mudando de ofertista-linear para o modelo sistêmico, como previsto em sua concepção. Para a consolidação desse modelo, o setor produtivo precisa estar inserido no processo inovativo. Dessa forma, apoiou-se na análise da presença ou não da empresa em dois objetos dos Fundos Sociais. Os resultados apontam que nem as agências de fomento, nem os projetos aprovados têm buscado estimular a cooperação universidade-empresa. Assim, o que se verifica é que não houve uma redefinição para o modelo sistêmico de inovação, e sim que a política de promoção de CT&I continua a seguir um modelo linear, mas agora induzido pela demanda.
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La tomodensitométrie (CT) est une technique d'imagerie dont l'intérêt n'a cessé de croître depuis son apparition dans le début des années 70. Dans le domaine médical, son utilisation est incontournable à tel point que ce système d'imagerie pourrait être amené à devenir victime de son succès si son impact au niveau de l'exposition de la population ne fait pas l'objet d'une attention particulière. Bien évidemment, l'augmentation du nombre d'examens CT a permis d'améliorer la prise en charge des patients ou a rendu certaines procédures moins invasives. Toutefois, pour assurer que le compromis risque - bénéfice soit toujours en faveur du patient, il est nécessaire d'éviter de délivrer des doses non utiles au diagnostic.¦Si cette action est importante chez l'adulte elle doit être une priorité lorsque les examens se font chez l'enfant, en particulier lorsque l'on suit des pathologies qui nécessitent plusieurs examens CT au cours de la vie du patient. En effet, les enfants et jeunes adultes sont plus radiosensibles. De plus, leur espérance de vie étant supérieure à celle de l'adulte, ils présentent un risque accru de développer un cancer radio-induit dont la phase de latence peut être supérieure à vingt ans. Partant du principe que chaque examen radiologique est justifié, il devient dès lors nécessaire d'optimiser les protocoles d'acquisitions pour s'assurer que le patient ne soit pas irradié inutilement. L'avancée technologique au niveau du CT est très rapide et depuis 2009, de nouvelles techniques de reconstructions d'images, dites itératives, ont été introduites afin de réduire la dose et améliorer la qualité d'image.¦Le présent travail a pour objectif de déterminer le potentiel des reconstructions itératives statistiques pour réduire au minimum les doses délivrées lors d'examens CT chez l'enfant et le jeune adulte tout en conservant une qualité d'image permettant le diagnostic, ceci afin de proposer des protocoles optimisés.¦L'optimisation d'un protocole d'examen CT nécessite de pouvoir évaluer la dose délivrée et la qualité d'image utile au diagnostic. Alors que la dose est estimée au moyen d'indices CT (CTDIV0| et DLP), ce travail a la particularité d'utiliser deux approches radicalement différentes pour évaluer la qualité d'image. La première approche dite « physique », se base sur le calcul de métriques physiques (SD, MTF, NPS, etc.) mesurées dans des conditions bien définies, le plus souvent sur fantômes. Bien que cette démarche soit limitée car elle n'intègre pas la perception des radiologues, elle permet de caractériser de manière rapide et simple certaines propriétés d'une image. La seconde approche, dite « clinique », est basée sur l'évaluation de structures anatomiques (critères diagnostiques) présentes sur les images de patients. Des radiologues, impliqués dans l'étape d'évaluation, doivent qualifier la qualité des structures d'un point de vue diagnostique en utilisant une échelle de notation simple. Cette approche, lourde à mettre en place, a l'avantage d'être proche du travail du radiologue et peut être considérée comme méthode de référence.¦Parmi les principaux résultats de ce travail, il a été montré que les algorithmes itératifs statistiques étudiés en clinique (ASIR?, VEO?) ont un important potentiel pour réduire la dose au CT (jusqu'à-90%). Cependant, par leur fonctionnement, ils modifient l'apparence de l'image en entraînant un changement de texture qui pourrait affecter la qualité du diagnostic. En comparant les résultats fournis par les approches « clinique » et « physique », il a été montré que ce changement de texture se traduit par une modification du spectre fréquentiel du bruit dont l'analyse permet d'anticiper ou d'éviter une perte diagnostique. Ce travail montre également que l'intégration de ces nouvelles techniques de reconstruction en clinique ne peut se faire de manière simple sur la base de protocoles utilisant des reconstructions classiques. Les conclusions de ce travail ainsi que les outils développés pourront également guider de futures études dans le domaine de la qualité d'image, comme par exemple, l'analyse de textures ou la modélisation d'observateurs pour le CT.¦-¦Computed tomography (CT) is an imaging technique in which interest has been growing since it first began to be used in the early 1970s. In the clinical environment, this imaging system has emerged as the gold standard modality because of its high sensitivity in producing accurate diagnostic images. However, even if a direct benefit to patient healthcare is attributed to CT, the dramatic increase of the number of CT examinations performed has raised concerns about the potential negative effects of ionizing radiation on the population. To insure a benefit - risk that works in favor of a patient, it is important to balance image quality and dose in order to avoid unnecessary patient exposure.¦If this balance is important for adults, it should be an absolute priority for children undergoing CT examinations, especially for patients suffering from diseases requiring several follow-up examinations over the patient's lifetime. Indeed, children and young adults are more sensitive to ionizing radiation and have an extended life span in comparison to adults. For this population, the risk of developing cancer, whose latency period exceeds 20 years, is significantly higher than for adults. Assuming that each patient examination is justified, it then becomes a priority to optimize CT acquisition protocols in order to minimize the delivered dose to the patient. Over the past few years, CT advances have been developing at a rapid pace. Since 2009, new iterative image reconstruction techniques, called statistical iterative reconstructions, have been introduced in order to decrease patient exposure and improve image quality.¦The goal of the present work was to determine the potential of statistical iterative reconstructions to reduce dose as much as possible without compromising image quality and maintain diagnosis of children and young adult examinations.¦The optimization step requires the evaluation of the delivered dose and image quality useful to perform diagnosis. While the dose is estimated using CT indices (CTDIV0| and DLP), the particularity of this research was to use two radically different approaches to evaluate image quality. The first approach, called the "physical approach", computed physical metrics (SD, MTF, NPS, etc.) measured on phantoms in well-known conditions. Although this technique has some limitations because it does not take radiologist perspective into account, it enables the physical characterization of image properties in a simple and timely way. The second approach, called the "clinical approach", was based on the evaluation of anatomical structures (diagnostic criteria) present on patient images. Radiologists, involved in the assessment step, were asked to score image quality of structures for diagnostic purposes using a simple rating scale. This approach is relatively complicated to implement and also time-consuming. Nevertheless, it has the advantage of being very close to the practice of radiologists and is considered as a reference method.¦Primarily, this work revealed that the statistical iterative reconstructions studied in clinic (ASIR? and VECO have a strong potential to reduce CT dose (up to -90%). However, by their mechanisms, they lead to a modification of the image appearance with a change in image texture which may then effect the quality of the diagnosis. By comparing the results of the "clinical" and "physical" approach, it was showed that a change in texture is related to a modification of the noise spectrum bandwidth. The NPS analysis makes possible to anticipate or avoid a decrease in image quality. This project demonstrated that integrating these new statistical iterative reconstruction techniques can be complex and cannot be made on the basis of protocols using conventional reconstructions. The conclusions of this work and the image quality tools developed will be able to guide future studies in the field of image quality as texture analysis or model observers dedicated to CT.
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És objectiu d'aquest projecte dotar la comunitat UOC d'una aplicació per a dispositius Android que proporcioni als usuaris de la comunitat UOC un eina, àgil, còmode i intuïtiva d'accés al Campus Virtual i als recursos formatius que conté.
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El siguiente proyecto consiste en el desarrollo de una tienda virtual dedicada a la venta de vino ecológico. El objetivo a grandes rasgos de la tienda virtual no debe ser diferente al de una tienda física. Además de la propia tecnología J2EE, se han utilizado patrones de diseño (MVC), frameworks (Struts2, JavaEmail), contenido web (JSP, CSS) y tratamientos de bases de datos (SQL).
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Este TFC consiste en una aplicación web sobre ASP.NET que gestiona el catálogo de una librería y permite realizar pedidos de libros.
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En aquesta memòria es presenta el desenvolupament d'un entorn virtual orientat a la didàctica de la lògica proposicional, aplicada en assignatures de Lògica Computacional i Estructura i Tecnologia de Computadors. L'entorn en si té com a objectiu ser un reforç a l'aprenentatge autodidacta per part de l'alumne en aquestes matèries, així com una eina de seguiment per part del professor.
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Aquest treball explica el funcionament del simulador ESPADDA i les técniques utilitzades. A partir d'aqui l'objectiu es implementar i explicar les noves funcionalitats afegides en el simulador. Aquestes són la integració del subsistema de memoria virtual, l'extensió del simulador cap a un entorn multiprogramat a nivell de tasques locals i tasques paral·leles i la implementació de les neus algorismes de mapping que tenen en compte els recursos limitats de l'estructura del sistema.
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Perfusion CT studies of regional cerebral blood flow (rCBF), involving sequential acquisition of cerebral CT sections during IV contrast material administration, have classically been reported to be achieved at 120 kVp. We hypothesized that using 80 kVp should result in the same image quality while significantly lowering the patient's radiation dose, and we evaluated this assumption. In five patients undergoing cerebral CT survey, one section level was imaged at 120 kVp and 80 kVp, before and after IV administration of iodinated contrast material. These four cerebral CT sections obtained in each patient were analyzed with special interest to contrast, noise, and radiation dose. Contrast enhancement at 80 kVp is significantly increased (P < .001), as well as contrast between gray matter and white matter after contrast enhancement (P < .001). Mean noise at 80 kVp is not statistically different (P = .042). Finally, performance of perfusion CT studies at 80 kVp, keeping mAs constant, lowers the radiation dose by a factor of 2.8. We, thus, conclude that 80 kVp acquisition of perfusion CT studies of rCBF will result in increased contrast enhancement and should improve rCBF analysis, with a reduced patient's irradiation.