Otimização da imagem em tomografia computorizada no exame de tórax

Mestrado em Radiações Aplicadas às Tecnologias da Saúde. Área de especialização: Imagem Digital.

Contributo para a acreditação nos serviços de imagiologia em Portugal

RESUMO - Os programas de acreditação revelam-se essenciais para monitorizar e garantir a qualidade dos serviços de imagiologia. Face à inexistência de um documento nacional de acreditação que responda às necessidades específicas de um serviço de imagiologia e perante a existência de diferentes estratégias de implementação da qualidade a nível internacional, definiu-se como principal objectivo deste trabalho contribuir para a criação de um documento de acreditação específico para serviços de imagiologia adaptado à realidade portuguesa. Nesse sentido, o presente trabalho pretende, através da aplicação de um questionário, desenvolvido para o efeito, a um grupo de peritos (painel Delphi) representante de organizações da área da imagiologia e da qualidade, analisar o consenso entre os elementos relevantes na acreditação de um serviço de imagiologia, nomeadamente ao nível da estrutura, processo e resultado. Como resultados esperados destacam-se a estruturação de um documento de consenso para a acreditação nos serviços de imagiologia em Portugal. Por certo, a aplicação de um quadro normativo emanado deste trabalho, na implementação da qualidade em imagiologia, permitirá que os serviços melhorem a sua prestação, que sejam avaliados e comparados com os congéneres, nacional ou internacionalmente, permitindo aos utentes ter mais e melhor informação que lhes permita optar por serviços com qualidade. -------------------------ABSTRACT - Accreditation programs are essential to monitor and ensure the quality of Imaging Services. Due to the lack of a national accreditation document that meets the specific needs of an imaging service and due to the existence of different international quality implementation strategies, the main purpose of this work is to contribute to the creation of a Portuguese imaging services accreditation document. Therefore, the present study aims to apply a inquiry to a group of experts (Delphi panel), that represents the structures and organizations that should integrate the development of the imaging services accreditation document, to analyze the consensus among experts about characteristics of accreditation, particularly the structure, process and outcome of imaging services. The expected results are the increased interest of decision-makers in promoting structural changes in the area of accreditation in Imaging and the creation of a document that evidences the consensus among experts. Finally, it is hoped that the same group of experts meets for accreditation document. The expected results include designing a consensus document for accreditation in imaging services in Portugal. Certainly, the implementation of a regulatory framework emerging from this work, in the implementation of quality imaging, will allow services to improve their performance, which are evaluated and compared with national or international counterparts. Consequently, patients will have better information that will enable them to opt for quality services.

Casuística dos exames de diagnóstico por imagem na medicina de animais selvagens - 2009 a 2010

The aim of this study was to retrospectively evaluate in the casuistry on class and systems frequently diagnosed in wild animals that were sent to the FMVZ-UNESP-Botucatu diagnostic imaging service. The class of birds was the most referred to the centers, followed by the mammals and reptiles. The majority of the requested tests were the radiographs and in a minor scale the tomography and ultrasound. Although the birds were the greatest number of animals sent to the service, mammals were the most radiographed for wound control. The most frequently observed system was the musculoskeletal caused by trauma, especially in birds. The radiograph was the most exam initially indicated, then the animal could be forwarded to other imaging modalities, which in wild animals medicine is still limited to research.

Estudo de doses e otimização de carta técnica na transição de radiologia convencional para computacional em diagnósticos veterinários

This project aims the verification of doses in canines and felines to chest and coxal exams due to the transition from screen-film to computed radiography system. It also seeks a possible optimization of the new techniques employed in this new system. The study was carried out in Diagnostic Imaging service in Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo using a conventional x-ray equipment. Initially, data about the physical characteristics of animals and the technique currently used in computed radiography was collected for each of 80 chest and 16 coxal X-ray examinations. The animals were divided into different groups according to the body weight. For each group, were calculated the averages of each item: thickness of the region to be imaged, voltage, current, exposure time, current-time product, size of film used, presence or absence of bucky and focus (small or large). The techniques have been reproduced in phantoms (representative of the thickness of the animal) in order to collect the air kerma entrance. Based on the average of intermediate size M group (weights less than 5 kg for cats and from 10.1 kg and 20 kg for dogs) analysis of image quality using three devices test patterns were made consisting of the evaluation of spatial resolution, low-contrast resolution and contrast-detail. In general, the results showed the dose animals decreased with the use of computed radiography and was possible to preliminary optimization of some techniques used currently in CR

Casuística dos exames de diagnóstico por imagem na medicina de animais selvagens - 2009 a 2010

The aim of this study was to retrospectively evaluate in the casuistry on class and systems frequently diagnosed in wild animals that were sent to the FMVZ–UNESP-Botucatu diagnostic imaging service. The class of birds was the most referred to the centers, followed by the mammals and reptiles. The majority of the requested tests were the radiographs and in a minor scale the tomography and ultrasound. Although the birds were the greatest number of animals sent to the service, mammals were the most radiographed for wound control. The most frequently observed system was the musculoskeletal caused by trauma, especially in birds. The radiograph was the most exam initially indicated, then the animal could be forwarded to other imaging modalities, which in wild animals medicine is still limited to research.

Contributos para implementação de um serviço de Imagiologia no Huambo, Angola

O Governo angolano tem realizado investimentos para a aquisição de tecnologias e incentivado investimentos privados no país para melhor tratar os problemas de saúde pública. Na província do Huambo o número de serviços de imagiologia é relativamente baixo, tendo em conta o número de habitantes. Dentre os serviços existentes, grande parte não possui uma estrutura funcional com a proteção radiológica recomendada, contam com poucos profissionais qualificados e os equipamentos não recebem uma manutenção adequada. Neste contexto, o Huambo representa uma região recetiva à instalação de um novo serviço de imagiologia, com capacidade de atender as necessidades dos utentes e profissionais. O presente trabalho objetiva contribuir para a implementação de um serviço de imagiologia no município do Huambo, a ser desenvolvido consoante às recomendações de boas práticas e normas de proteção radiológica, apoiado pela Lei do Investimento Privado.

The ... annual report of the American Museum of Natural History.

Vols. for 1924-1931 bear also distinctive titles.

The ... annual report of the American Museum of Natural History.

Vols. for 1924-1931 bear also distinctive titles.

Spectrum of morphological and visual changes due to vitreomacular interface disorders encountered in a large consecutive cohort of patients

Aim: Identify the incidence of vitreomacular traction (VMT) and frequency of reduced vision in the absence of other coexisting macular pathology using a pragmatic classification system for VMT in a population of patients referred to the hospital eye service. Methods: A detailed survey of consecutive optical coherence tomography (OCT) scans was done in a high-throughput ocular imaging service to ascertain cases of vitreomacular adhesion (VMA) and VMT using a departmental classification system. Analysis was done on the stages of traction, visual acuity, and association with other macular conditions. Results: In total, 4384 OCT scan episodes of 2223 patients were performed. Two hundred and fourteen eyes had VMA/VMT, with 112 eyes having coexisting macular pathology. Of 102 patients without coexisting pathology, 57 patients had VMT grade between 2 and 8, with a negative correlation between VMT grade and number of Snellen lines (r= -0.61717). There was a distinct cutoff in visual function when VMT grade was higher than 4 with the presence of cysts and sub retinal separation and breaks in the retinal layers. Conclusions: VMT is a common encounter often associated with other coexisting macular pathology. We estimated an incidence rate of 0.01% of VMT cases with reduced vision and without coexisting macular pathology that may potentially benefit from intervention. Grading of VMT to select eyes with cyst formation as well as hole formation may be useful for targeting patients who are at higher risk of visual loss from VMT.

Scheduling medical application workloads on virtualized computing systems

This dissertation presents and evaluates a methodology for scheduling medical application workloads in virtualized computing environments. Such environments are being widely adopted by providers of "cloud computing" services. In the context of provisioning resources for medical applications, such environments allow users to deploy applications on distributed computing resources while keeping their data secure. Furthermore, higher level services that further abstract the infrastructure-related issues can be built on top of such infrastructures. For example, a medical imaging service can allow medical professionals to process their data in the cloud, easing them from the burden of having to deploy and manage these resources themselves. In this work, we focus on issues related to scheduling scientific workloads on virtualized environments. We build upon the knowledge base of traditional parallel job scheduling to address the specific case of medical applications while harnessing the benefits afforded by virtualization technology. To this end, we provide the following contributions: (1) An in-depth analysis of the execution characteristics of the target applications when run in virtualized environments. (2) A performance prediction methodology applicable to the target environment. (3) A scheduling algorithm that harnesses application knowledge and virtualization-related benefits to provide strong scheduling performance and quality of service guarantees. In the process of addressing these pertinent issues for our target user base (i.e. medical professionals and researchers), we provide insight that benefits a large community of scientific application users in industry and academia. Our execution time prediction and scheduling methodologies are implemented and evaluated on a real system running popular scientific applications. We find that we are able to predict the execution time of a number of these applications with an average error of 15%. Our scheduling methodology, which is tested with medical image processing workloads, is compared to that of two baseline scheduling solutions and we find that it outperforms them in terms of both the number of jobs processed and resource utilization by 20–30%, without violating any deadlines. We conclude that our solution is a viable approach to supporting the computational needs of medical users, even if the cloud computing paradigm is not widely adopted in its current form.

Complete internal audit of a mammography service in a reference institution for breast imaging

Objective Undertaking of a complete audit of the service of mammography, as recommended by BI-RADS®, in a private reference institution for breast cancer diagnosis in the city of São Paulo, SP, Brazil, and comparison of results with those recommended by the literature. Materials and Methods Retrospective, analytical and cross-sectional study including 8,000 patients submitted to mammography in the period between April 2010 and March 2011, whose results were subjected to an internal audit. The patients were followed-up until December 2012. Results The radiological classification of 7,249 screening mammograms, according to BI-RADS, was the following: category 0 (1.43%), 1 (7.82%), 2 (80.76%), 3 (8.35%), 4 (1.46%), 5 (0.15%) and 6 (0.03%). The breast cancer detection ratio was 4.8 cases per 1,000 mammograms. Ductal carcinoma in situ was found in 22.8% of cases. Positive predictive values for categories 3, 4 and 5 were 1.3%, 41.3% and 100%, respectively. In the present study, the sensitivity of the method was 97.1% and specificity, 97.4%. Conclusion The complete internal audit of a service of mammography is essential to evaluate the quality of such service, which reflects on an early breast cancer detection and reduction of mortality rates.

Geospatial assessment of pest-induced forest damage through the use of UAV-bases NIR imaging and Gi-technology

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Spinal cord ischemia : clinical and imaging patterns, pathogenesis, and outcomes in 27 patients

RÉSUMÉ Introduction: l'histoire naturelle et la physiopathologie des infarctus de la moelle épinière restent largement inconnues. En effet, la plupart des études cliniques portent sur des patients qui ont souffert d'infarctus médullaire secondaire à des chirurgies aortiques ou des hypotensions prolongées. Méthode: ce travail analyse les données cliniques, le laboratoire, l'imagerie (IRM) et l'évolution de 27 patients souffrant d'infarctus de la moelle épinière admis dans le service de Neurologie du CHUV. Parmi ces patients, il y avait 11 hommes et 16 femmes (âge moyen de 56 ans, tranche d'âge de 19 à 80 ans). Résultats: dix patients (37%) souffraient d'infarctus de l'artère spinale antérieure, 4 (15%) d'infarctus unilatéraux antérieurs, 4 (15%) unilatéraux postérieurs, 3 (11%) d'infarctus centraux, 2 (7%) d'infarctus des artères spinales postérieures, 2 (7%) d'infarctus transverse tandis que 2 patients présentaient des tableaux cliniques inclassables. Vingt patients (74%) n'avaient pas d'étiologie identifiable. Les patients avec infarctus centraux ou transverses présentaient fréquemment (40%) des artériopathies périphériques et tous les infarctus transverses survenaient à la suite d'hypotensions artérielles prolongées. Le début de tous les autres types d'infarctus était associé à des facteurs mécaniques (p=0.02} et ces patients avaient fréquemment des pathologies du rachis (p=0.003) au niveau de la lésion médullaire. Dans ces cas, les données cliniques suggèrent une lésion d'une racine nerveuse au niveau de l'infarctus médullaire compromettant mécaniquement le flux de son artère radiculaire. L'évolution clinique était généralement favorable, seuls 13 patients (48%) présentaient une atteinte significative de la marche à la sortie de l'hôpital. Conclusion: ce travail montre qu'il existe 2 types principaux d'infarctus de la moelle épinière : d'une part les infarctus dans le territoire d'une artère radiculaire (infarctus de l'artère spinale antérieure, des artères spinales postérieures et infarctus unilatéraux) et d'autre part les hypoperfusions régionales globales de la moelle épinière (infarctus centraux et transverses). Chacune de ces 2 catégories d'infarctus ont des caractéristiques cliniques, radiologiques, physiopathologiques et pronostiques distinctes.

Assessment of pelvic floor by three-dimensional-ultrasound in primiparous women according to delivery mode: initial experience from a single reference service in Brazil

PURPOSE: To evaluate changes to the pelvic floor of primiparous women with different delivery modes, using three-dimensional ultrasound. METHODS: A prospective cross-sectional study on 35 primiparae divided into groups according to the delivery mode: elective cesarean delivery (n=10), vaginal delivery (n=16), and forceps delivery (n=9). Three-dimensional ultrasound on the pelvic floor was performed on the second postpartum day with the patient in a resting position. A convex volumetric transducer (RAB4-8L) was used, in contact with the large labia, with the patient in the gynecological position. Biometric measurements of the urogenital hiatus were taken in the axial plane on images in the rendering mode, in order to assess the area, anteroposterior and transverse diameters, average thickness, and avulsion of the levator ani muscle. Differences between groups were evaluated by determining the mean differences and their respective 95% confidence intervals. The proportions of levator ani muscle avulsion were compared between elective cesarean section and vaginal birth using Fisher's exact test. RESULTS: The mean areas of the urogenital hiatus in the cases of vaginal and forceps deliveries were 17.0 and 20.1 cm², respectively, versus 12.4 cm² in the Control Group (elective cesarean). Avulsion of the levator ani muscle was observed in women who underwent vaginal delivery (3/25), however there was no statistically significant difference between cesarean section and vaginal delivery groups (p=0.5). CONCLUSION: Transperineal three-dimensional ultrasound was useful for assessing the pelvic floor of primiparous women, by allowing pelvic morphological changes to be differentiated according to the delivery mode.