INTRODUÇÃO: Os tomógrafos multidetectores (TCMD) aumentaram a sensibilidade na detecção do tromboembolismo pulmonar (TEP). Observa-se, no entanto, um substancial aumento no número de imagens e, conseqüentemente, no tempo de análise pelo radiologista. Uma possível solução, para este problema, é a realização de reconstruções em projeção de intensidade máxima (MIP) que reduz o número de imagens para análise. Existe ainda uma nova modalidade de imagem utilizando reconstrução MIP em planos rotacionais sobre um eixo horizontal ao nível dos hilos pulmonares (reformatação em pás de roda moinho, PRM), que tem demonstrado melhor a continuidade dos ramos arteriais que irradiam dos hilos. No entanto, estudos são necessários para determinar se o uso de reformatações MIP pode reduzir o número de imagens a serem analisadas, sem perda significativa de informações, e se a adição de reformatação PRM pode melhorar o diagnóstico de TEP. OBJETIVOS: Testar a hipótese de que imagens utilizando reconstruções em projeção de intensidade máxima de 2,0 mm e 4,0 mm de espessura, multiplanares, têm o mesmo valor diagnóstico para detecção de TEP nas grandes e pequenas artérias pulmonares, quando comparadas a imagens multiplanares de 1 mm, realizadas em TCMD de 10 e 16 fileiras de detectores. Avaliar se há influência no valor diagnóstico de TEP o acréscimo de reformatações PRM, nas imagens reconstruídas em MIP de 2 mm. CASUÍSTICA E MÉTODOS: Cinqüenta pacientes com suspeita diagnóstica de TEP (30 com TEP positivo e 20 com TEP negativo, detectados no exame tomográfico), realizaram tomografia computadorizada do tórax para avaliação das artérias pulmonares em TCMD com 16 e 10 fileiras de detectores (120 kV, 200 mAs e 1 mm de colimação). Cada exame foi reconstruído em 4 tipos de séries de imagens multiplanares: imagens multiplanares (MPR) de 1 mm e 3 tipos de reconstrução MIP, com espessuras de 2 mm, 4 mm e 2 mm acrescidas de reformatação PRM. Dois observadores avaliaram, independentemente, em estação de trabalho, a presença ou ausência de êmbolos nas artérias principais, lobares, segmentares e subsegmentares dos 50 pacientes em cada uma das reconstruções MIP, as quais foram comparadas usando-se a reformatação MPR de 1 mm como padrão de referência. RESULTADOS: As reconstruções MIP de 2 mm tiveram melhor acurácia, estatisticamente significativa, em relação a MIP de 4 mm, com valores de sensibilidade 100,0 e 100.0 para as artérias principais e lobares; 92,6 e 85,5 para as segmentares e 94,3 e 86,8 para as subsegmentares. Utilizando as imagens multiplanares de 1 mm como referência padrão. Todos pacientes com TEP foram detectados com imagens em MIP de 2 mm. Dois pacientes com TEP não foram diagnosticados com imagens em MIP de 4 mm. Não houve diferença estatisticamente significativa entre a reformatação MIP de 2 mm e 2 mm + PRM na detecção de êmbolos. CONCLUSÃO: Com um número de imagens equivalente a metade da reconstrução MPR de 1 mm, a reconstrução em MIP de 2 mm conseguiu detectar todos os pacientes com TEP positivo que foram diagnosticados pelas imagens multiplanares de 1 mm, com sensibilidade de 100,0 e 100,0 nas artérias principais e lobares, de 92,6 e 85,5 para as artérias segmentares e 94,3 e 86,8 para as artérias subsegmentares. O acréscimo de reformatações PRM às imagens em MIP de 2 mm não aumentou a acurácia na detecção de êmbolos, mas melhorou a visualização da continuidade dos êmbolos, principalmente, nas artérias centrais. / INTRODUCTION: Multidetector computed tomography (MDCT) has been making possible the increase of the sensibility in the detection of the pulmonary embolism (PE). It is observed, however, that there is a substantial increase in the number of images and, consequently, in the time of analysis for the radiologist. A possible solution to this problem is accomplishing a maximum intensity projection reconstruction (MIP) that reduces the number of images for analysis. Still, there is a new image modality using MIP reconstructions in rotational plans that pivot on a central horizontal axis between the lung hila (paddlewheel reformations, PDW). It provides a continuous display of branching arteries that radiate from both hila. However, studies are necessary to determine if the use of multiplan MIP reformation can reduce the number of images to be analyzed, without significant loss of information; and, if the addition of PDW reformation can improve the diagnosis of PE. OBJECTIVE: To test the hypothesis that images using maximum intensity projection reconstructions of 2,0 mm and 4,0 mm of thickness, multiplan, have the same diagnosis value for detection of pulmonary embolism in the big and small pulmonary arteries, when compared to multiplan images of 1 mm collimation, accomplished in 16 and 10 slice MDTC; and to evaluate if there is influence on the diagnosis value of PE the increment of PDW reformation, in the images rebuilt in MIP of 2 mm. CASUISTIC AND METHODS: Fifty patients suspected of having an acute PE (30 with positive PE and 20 with negative PE, detected during the tomography exam) accomplished computerized tomography of the thorax for evaluation of the pulmonary arteries by 16 and 10 slice MDTC (120 kV, 200 mAs and 1 mm collimation). Four kind of images series (1 mm thick multiplan images and 3 kinds of reconstructed images using the MIP tecnhnique with slab thicknesses of 2 mm, 4 mm and 2 mm added of PDW reformation) were obtained from each exam. Two observers independently evaluated, in work station, the presence or absence of emboli in the main and lobar, segmental and subsegmental arteries in the 50 patients in each one of the reconstructions in MIP, which they were compared using the reformation of 1 mm of thickness as reference pattern. RESULTS: The reconstructions in MIP of 2 mm had better accuracy than MIP of 4 mm, statistically significant with values of sensibility 100,0 and 100,0 for the main and lobar pulmonary arteries; 92,6 and 85,5 for the segmental and 94,3 and 86,8 for the subsegmental. The images in MPR of 1 mm were used as a reference pattern. All patients with PE were detected with images in MIP of 2 mm; two patients with PE were not diagnosed with images in MIP of 4 mm. There was not difference statisticament significant among reformation in MIP of 2 mm and 2 mm plus PDW in the detection of emboli. CONCLUSION: Reconstruction in MIP of 2 mm reduced the number of images for the half and it detected all patients with positive PE that were diagnosed by the multiplans images of 1 mm, with sensibility of 100,0 and 100,0 in the main and lobar arteries, of 92,6 and 85,5 and 79,2 for the segmental arteries and 94,3 and 86,8 for the subsegmental arteries. The increment of PDW reformation to the images in MIP of 2 mm didn\'t increase the accuracy in the detection of emboli, but it improved the visualization of the continuity of the emboli, mainly, in the central arteries.

<p>Kompjuterizovana tomografija (CT) je u poslednje vreme ušla na velika vrata sa razvojem industrijskih CT sistema, usled njene primene u različitim oblastima, a uveliko ulazi i u polje koodinatne metrologije. Zbog karakterizacije objekata sačinjenih od različitih materijala (najčešće metala i plastike), javljaju se određeni problem u vidu nastanka artefakata kod rezultata dimenzionalnih merenja. Istraživanja koja su sprovedena u ovoj doktorskoj disertaciji se bave problemom redukcije uticaja tih artefakata i segmentacije 2D snimaka. Razvijen je novi model koji je baziran na primeni hibridne metode gde je izvršena kombinacija dve metode za obradu slike, a to su fazi klasterizacija i rast regiona. Aksenat je stavljen na primeni ove hibridne metode radi dobijanja tačnijih rezultata segmentacije, što direktno utiče i na rekonstrukciju dimenzionalno tačnijih 3D modela.</p> / <p>Computed tomography (CT) has recently entered a large door with the development of industrial CT systems, due to its application in many different areas, and it is already entering the field of coordinate metrology. Due to its ability to non-destructively characterize objects made of different materials (typicaly metals and plastics), a certain problem arises in the form of artefacts that are present in the results. Research carried out in this dissertation deals with the problem of reducing the impact of these artefacts and the 2D image segmentation. A new model was developed based on the application of the hybrid method where a combination of two methods for image processing was performed, which are fuzzy clustering and region growing. The accent is emphasized in the application of this hybrid method in order to obtain more accurate segmentation results, which directly affects the reconstruction of dimensionally more accurate 3D models.</p>

Moisture damage in asphalt mixes refers to the loss of serviceability due to the presence of moisture. The extent of moisture damage, also called moisture susceptibility, depends on internal and external factors. The internal factors relate to the properties of the materials and the microstructure distribution, while the external factors include the environmental conditions, production and construction practices, pavement design, and traffic level. The majority of the research on moisture damage is based on the hypothesis that infiltration of surface water is the main source of moisture. Of the two other principal mechanisms of water transport, permeation of water vapor and capillary rise of subsurface water, the latter has been least explored. A laboratory test and analysis methods based on X-ray computed tomography (CT) were established to assess the capillary rise of water. The amount and size of air voids filled with water were used in the capillary rise equation to estimate the distribution of the contact angles between the water and the mastic. The results were able to show the influence of air void size on capillary rise and contact angles. The relationship between air void structure and moisture susceptibility was evaluated using a fundamental fracture model based on dissipated energy of viscoelastic materials. Detailed description is provided in this dissertation on the deduction of the model equation, the selection of the model parameters, and the required testing protocols. The model parameters were obtained using mechanical tests and surface energy measurements. The microstructure of asphalt mixes prepared in the laboratory having different air void structures was captured using X-ray CT, and image analysis techniques were used to quantify the air void structure and air void connectivity. The air void structure was found to influence the mix resistance to moisture damage. To validate the fracture model, asphalt mixes with known field performance were tested. The results demonstrated that the fracture model is an effective tool to characterize moisture susceptibility. In addition, the model showed good correlation with the reported field performance of the asphalt mixes. The findings of this study will be useful to highway engineers to evaluate asphalt mixes with alternative mix designs and internal air void structures and to estimate the rate of moisture infiltration in order to maximize the resistance of asphalt mixes to moisture damage.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2008. / Härtill 5 uppsatser.

Thesis--University of Oklahoma. / Bibliography: leaves 113-115.

81f. / Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-23T16:52:09Z No. of bitstreams: 1 Dissertacao - Eduardo Gomes Ferraz.pdf: 6518404 bytes, checksum: 23aa21cb9faeb4f359532b341d12f69c (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-05-08T12:05:54Z (GMT) No. of bitstreams: 1 Dissertacao - Eduardo Gomes Ferraz.pdf: 6518404 bytes, checksum: 23aa21cb9faeb4f359532b341d12f69c (MD5) / Made available in DSpace on 2013-05-08T12:05:55Z (GMT). No. of bitstreams: 1 Dissertacao - Eduardo Gomes Ferraz.pdf: 6518404 bytes, checksum: 23aa21cb9faeb4f359532b341d12f69c (MD5) Previous issue date: 2009 / O presente estudo teve como objetivo avaliar a acurácia de reconstruções tridimensionais virtuais de mandíbulas secas humanas, produzidas com diferentes protocolos de segmentação, suavização e refinamento superficial. Para isto foram construídas 80 imagens tridimensionais virtuais, provenientes do exame de tomografia computadorizada de dez mandíbulas secas, nas quais medidas lineares entre pontos anatômicos pré-determinados foram obtidas e comparadas, para uma probabilidade de erro de 5%. Os resultados obtidos demonstraram diferença significativa entre as medidas obtidas nas mandíbulas originais (padrão ouro) quando comparadas com as imagens confeccionadas a partir da segmentação outline (p<0,05) e all boundary (p<0,001) sem as ferramentas de suavização ou refinamento. Já após a utilização das diferentes formas de segmentação associadas às ferramentas de pós-processamento (suavização e refinamento), não houve diferença entre as medidas dos modelos apenas refinados ou apenas suavizados (p>0,05) com as do padrão ouro. Quando estas duas ferramentas foram aplicadas em conjunto, houve diferença estatística, quando comparadas ao padrão ouro, tanto para a segmentação outline (p<0,001), quanto para a all boundary (p<0,001). Foi avaliado também o erro dimensional dos modelos tridimensionais virtuais obtidos pelos diferentes protocolos utilizados no estudo. Esta análise demonstrou que os melhores resultados ocorreram nos modelos apenas suavizados pela segmentação outline (erro de 2,50 mm /6,52%) e os apenas refinados pela segmentação all boundary (erro de 2,37 mm /6,28%), enquanto que as maiores diferenças foram observadas nos modelos construídos sem pós-processamento, com a segmentação outline (erro de 2,50 mm /7,17%) e naqueles com as duas ferramentas de pósprocessamento a partir da segmentação all boundary (erro de 2,85 mm /7,12%). Avaliada ainda a variabilidade intra e inter-examinador constatou-se uma concordância extremamente forte em ambos os casos (p<0,05), o que demonstra a reprodutibilidade do método. / Salvador

A microtomografia computadorizada (computed microtomography - &#956;CT) permite uma análise não destrutiva de amostras, além de possibilitar sua reutilização. A &#956;CT permite também a reconstrução de objetos tridimensionais a partir de suas seções transversais que são obtidas interceptando a amostra através de planos paralelos. Equipamentos de &#956;CT oferecem ao usuário diversas opções de configurações que alteram a qualidade das imagens obtidas afetando, dessa forma, o resultado esperado. Nesta tese foi realizada a caracterização e análise de imagens de &#956;CT geradas pelo microtomógrafo SkyScan1174 Compact Micro-CT. A base desta caracterização é o processamento de imagens. Foram aplicadas técnicas de realce (brilho, saturação, equalização do histograma e filtro de mediana) nas imagens originais gerando novas imagens e em seguida a quantificação de ambos os conjuntos, utilizando descritores de textura (probabilidade máxima, momento de diferença, momento inverso de diferença, entropia e uniformidade). Os resultados mostram que, comparadas às originais, as imagens que passaram por técnicas de realce apresentaram melhoras quando gerados seus modelos tridimensionais. / X-ray Computed Microtomography (&#956;CT) allows a non destructive analysis of samples besides making it possible to reuse them. &#956;CT also allows the reconstruction of tridimensional objects from its transverse sections obtained intersecting the sample through parallel planes. &#956;CT devices offer the user several configuration options which alter the quality of the images obtained affecting, this way, the results expected. In this study, the characterization and analysis of &#956;CT images generated by the X-ray tomograph scannerSkyScan1174 Compact Micro-CT was performed. The basis of this characterization is the processing of images. Enhancement techniques were applied (brightness, saturation, histogram equalization and median filter) in the original images creating new images. Next, the quantification of both sets was performed, using texture descriptors (maximum likelihood, moment of difference, inverse difference moment , entropy and uniformity). The results show that, compared to the originals, the images which went through enhancement techniques had improved when their three-dimensional models were generated.

The overall accuracy, efficiency and profitability of livestock improvement strategies can be greatly increased by incorporating quantitative genetics into livestock selection and breeding. Since the introduction of quantitative genetics, a range of traits describing the animal e.g. in terms of health, growth, fecundity, production, have been extensively evaluated in terms of genetics and are now commonly manipulated through breeding to achieve specific selection goals. An industry led enquiry as to the possibility of including spine traits in genetic selection to increase back length in sheep was the basis of the present thesis. Collecting information on spine traits (spine length, vertebrae length and vertebrae number) is of particular interest and use to the sheep breeding industry as there may be the potential to increase meat yield from the highly valuable longissimus thoracis et lumborum (LTL or loin), located parallel to the spine, with little associated change in production costs. The thesis focusses on the use of X-ray computed tomography (CT) scanning as a technique which would allow spine traits to be measured in vivo, hence being useful for genetic selection. The topogram scans produced from the CT scanning procedure were analysed to derive spine trait information for the thesis. The scans were from Scottish Blackface (maternal breed stock), Texel (terminal sire breed), Texel cross Mule and Poll Dorset cross Mule (three-way cross slaughter lambs) so as to represent the divergent genotypes found across the different levels of the United Kingdom’s (UK) three-tier crossbreeding structure of sheep. The present study explored as a first step intra- and inter-operator repeatability of assessment of spine traits from CT derived topograms, as a means to investigate the suitability of the approach for widespread uptake within industry where operators will vary. The results showed that there was high repeatability for intra- and inter-operator assessment of spine trait measurements verifying that the CT method could be accepted as a reliable alternative (to slaughter for example) to quantify spine traits. To determine whether spine traits are similar across the range of breeds representing the key genotypes and crosses in the UK sheep industry, numerous CT topograms were analysed. The results showed marked variation in spine traits within and between Scottish Blackface, Texel, Texel cross Mule and Poll Dorset cross Mule breeds and crosses. For example, the Texel breed was found to have the largest within-breed range for thoracolumbar vertebrae number (17 – 21; the majority possessing 19), but the spine length of these animals was, on average, significantly shorter than the other breed/cross groups. The present study concluded that the significant differences between the breeds and breed types for the particular spine traits were possibly indicative of a genetic control for these traits. Furthermore, investigation into the phenotypic correlations between spine and production traits revealed some directional associations which may prove beneficial for meat production. For example, Scottish Blackface lambs which had a longer length of a specific spine region had an associated decrease in the volume of carcass fat. Texel lambs which had a longer length of a specific spine region had a slightly larger loin muscle area, at a given weight. The present study also examined animals from a population of Texel lambs already heavily selected for increased muscling. The Texel muscling quantitative trait locus (TM-QTL), segregating in these animals and generally in the UK’s Texel sheep population, is expressed through a polar overdominance pattern of inheritance and its effect on the loin (localised muscle hypertrophy) is commonly utilised in the selection and breeding of Texel sheep to improve meat production. Examination of topograms from lambs bearing the whole range of TM-QTL genotypes showed little evidence to suggest that the change in loin shape/increased loin muscling, as a result of the TM-QTL and its inheritance, has led to any associated change in the underlying spine characteristics. This suggests that selection for increased muscling associated with the TM-QTL may be achieved independently of changes in the spine traits studied. The potential to breed for certain spine traits to increase vertebrae number and hence chops or loin yield can be enhanced by establishing the genetic parameters for the traits. The present study employed a collection of performance trait records from Texel lambs to provide the basis for genetic analysis. The results showed different levels of heritability for the different spine traits but also high standard errors. For example, heritability of vertebrae number was dependent on vertebra location: for thoracic vertebrae heritability was high (ℎ2 = 0.99; SE = 0.42), for lumbar vertebrae heritability was low (ℎ2 = 0.08; SE = 0.12), whereas in contrast, thoracolumbar vertebrae heritability was moderate (ℎ2 = 0.44; SE = 0.27). Phenotypic and genetic correlations between all combinations of traits were also obtained. Accurate predictions of the size and direction of response to selection can be achieved through such genetic analysis of traits. The more that is known of the genetic characteristics of traits and their genetic correlations with other economically important traits, the more efficiently it can be built into breeding programmes improving the overall performance of stock. The results of this study showed that providing spine measurements can contribute to the diversity of trait information available to breeders. The present study also suggests that there may be opportunities to select for increased spine length/vertebrae number which would benefit the sheep industry in terms of increased chop number/loin yield. Although more data are needed prior to implementation. Practical uptake of selection for spine traits would be enhanced due to the straightforward nature of the measurements and the high operator repeatability.

INTRODUÇÃO: A maioria dos estudos sobre baixa massa muscular e osso envolvem populações idosas. No entanto, como o hipoestrogenismo nos primeiros anos da menopausa é capaz de modular negativamente a massa óssea e muscular, é importante compreender a interação entre músculo e osso neste período. Além disso, há uma escassez de estudos que investigam a influência potencial da massa e função muscular sobre a qualidade óssea (microarquitetura e resistência), o que poderia fornecer uma visão mais abrangente do risco de fratura nesta população. O objetivo deste artigo foi avaliar as correlações potenciais entre parâmetros musculares (massa, força e função) e microarquitetura e resistência óssea utilizando a tomografia computadorizada periférica de alta resolução (HR-pQCT) em mulheres pós-menopáusicas. MÉTODOS: Um total de 225 mulheres menopausadas saudáveis (56,4 ± 4,6 anos) foram avaliadas por questionário clínico, exames laboratoriais e composição corporal (DXA, Hologic, QDR-4500). A qualidade dos ossos (densidade, microarquitetura, porosidade cortical e resistência) foi analisada por tomografia computadorizada periférica de alta resolução (rádio distal e tíbia, XtremeCT, Scanco Medical, Brüttisellen, Suíça). A mobilidade funcional e o desempenho muscular foram medidos pela força de preensão palmar (dinamômetro do modelo JAMAR), testes de levantar e sentar em 30 segundos e teste de levantar e caminhar cronometrado. O equilíbrio foi avaliado pela Escala de equilíbrio de Berg. A correlação entre parâmetros ósseos (HR-pQCT) e desempenho muscular foi analisada pelo teste de Spearman (p < 0,05). RESULTADOS: No rádio, houve correlações positivas entre a força de preensão palmar e os parâmetros do HR-pQCT do osso trabecular (densidade mineral óssea volumétrica trabecular [Tb.vBMD]: r = 0,17, p = 0,03, espessura trabecular [Tb.Th]: r = 0,16, p = 0,04), bem como entre a força muscular e a resistência óssea (Rigidez [S]: r = 0,36, p < 0,001). Na tíbia, a massa muscular da perna esquerda foi correlacionada positivamente com o número de trabéculas [Tb.N] (r = 0,16, p < 0,001), separação trabecular [Tb.Sp]: r = - 0,15, p = 0,02), espessura cortical [Ct.Th] (r = 0,21, p = 0,01) e resistência óssea [S] (r = 0,37, p < 0,001). Não houve correlações significativas entre os parâmetros de HR-pQCT e os testes funcionais dos membros inferiores, exceto entre o equilíbrio e a Tb.vBMD na tíbia (r = 0,13, p = 0,04). Houve uma correlação negativa entre a gordura corporal total e a função muscular (teste de levantar e sentar em 30 segundos: r = - 0,21, p < 0,001, escala de equilíbrio de Berg: r = -0,21, p < 0,001). CONCLUSÃO: nas mulheres, nos primeiros anos da menopausa, a força muscular parece desempenhar um papel mais importante nos parâmetros ósseos do membro superior (rádio), enquanto a massa muscular parece exercer maior influência no osso do membro inferior (tíbia). Esses achados sugerem uma diferença na relação entre músculo e osso de acordo com os diferentes segmentos do corpo. Além disso, a correlação negativa entre gordura corporal com função e equilíbrio muscular indica que o aumento da massa gorda corporal pode conferir maior risco de quedas nesta população. Estudos longitudinais são necessários para confirmar esses dados / INTRODUCTION: Most studies on low muscle mass and bone involve elderly populations. However, because postmenopausal hypoestrogenism is able to negatively modulate bone and muscle mass, it is important to understand the interplay between muscle and bone in early menopause. In addition, there is a paucity of studies investigating the potential influence of muscle mass and function upon bone quality (microarchitecture and strength), which could provide a more comprehensive view of fracture risk in this population. The aim of this article was to assess the potential correlations between muscle parameters (mass, strength and function), and bone microarchitecture and strength using high-resolution peripheral computed tomography (HR-pQCT) in postmenopausal women. METHODS: A total of 225 healthy menopausal women (aged 56.4 ± 4.6 years) were evaluated by clinical questionnaire, laboratory and body composition (DXA, Hologic, QDR-4500). Bone quality (density, microarchitecture, strength and cortical porosity) was analyzed by high resolution peripheral computed tomography (distal radius and tibia, XtremeCT, Scanco Medical, Brüttisellen, Switzerland). Functional mobility and muscle performance were measured by hand grip strength (JAMAR model dynamometer), Timed-Stand and Timed Up & Go tests. Balance was assessed by the Berg Balance Scale. The correlation between bone parameters (HR-pQCT) and muscle performance was analyzed by the Spearman test (p < 0.05). RESULTS: At the radius, there were positive correlations between hand grip strength and trabecular bone HR-pQCT parameters (trabecular volumetric bone mineral density [Tb.vBMD]: r=0.17, p = 0.03, trabecular thickness [Tb.Th]: r=0.16, p=0.04), as well as between muscle strength and bone strength (Stiffness [S]: r = 0.36, p < 0.001). At the tibia, the left leg muscle mass was positively correlated with number of trabeculae [Tb.N] (r = 0.16, p < 0.001), trabecular separation [Tb.Sp]: r=- 0.15, p= 0.02), cortical thickness [Ct.Th] (r = 0.21, p = 0.01) and bone strength [S] (r= 0.37, p < 0.001). There were no significant correlations between HR-pQCT parameters and lower limb functional tests, except between the balance and tibial Tb.vBMD (r= 0.13, p = 0.04). There was a negative correlation between total body fat and muscle function (30-s chair test: r = -0.21, p < 0.001, balance: r = -0.21, p < 0.001). CONCLUSION: In postmenopausal women, muscle strength seems to play a more important role in the upper limb bone (radius) parameters, whereas muscle mass seems to exert a higher influence on the lower limb bone (tibia). These findings suggest a difference on relationship between muscle and bone according to distinct body segments. In addition, the negative correlation between body fat and balance/muscle function indicate that increased body fat mass might confer increased risk of falls in this population. Longitudinal studies are needed to test these assumptions

INTRODUÇÃO: Os tomógrafos multidetectores (TCMD) aumentaram a sensibilidade na detecção do tromboembolismo pulmonar (TEP). Observa-se, no entanto, um substancial aumento no número de imagens e, conseqüentemente, no tempo de análise pelo radiologista. Uma possível solução, para este problema, é a realização de reconstruções em projeção de intensidade máxima (MIP) que reduz o número de imagens para análise. Existe ainda uma nova modalidade de imagem utilizando reconstrução MIP em planos rotacionais sobre um eixo horizontal ao nível dos hilos pulmonares (reformatação em pás de roda moinho, PRM), que tem demonstrado melhor a continuidade dos ramos arteriais que irradiam dos hilos. No entanto, estudos são necessários para determinar se o uso de reformatações MIP pode reduzir o número de imagens a serem analisadas, sem perda significativa de informações, e se a adição de reformatação PRM pode melhorar o diagnóstico de TEP. OBJETIVOS: Testar a hipótese de que imagens utilizando reconstruções em projeção de intensidade máxima de 2,0 mm e 4,0 mm de espessura, multiplanares, têm o mesmo valor diagnóstico para detecção de TEP nas grandes e pequenas artérias pulmonares, quando comparadas a imagens multiplanares de 1 mm, realizadas em TCMD de 10 e 16 fileiras de detectores. Avaliar se há influência no valor diagnóstico de TEP o acréscimo de reformatações PRM, nas imagens reconstruídas em MIP de 2 mm. CASUÍSTICA E MÉTODOS: Cinqüenta pacientes com suspeita diagnóstica de TEP (30 com TEP positivo e 20 com TEP negativo, detectados no exame tomográfico), realizaram tomografia computadorizada do tórax para avaliação das artérias pulmonares em TCMD com 16 e 10 fileiras de detectores (120 kV, 200 mAs e 1 mm de colimação). Cada exame foi reconstruído em 4 tipos de séries de imagens multiplanares: imagens multiplanares (MPR) de 1 mm e 3 tipos de reconstrução MIP, com espessuras de 2 mm, 4 mm e 2 mm acrescidas de reformatação PRM. Dois observadores avaliaram, independentemente, em estação de trabalho, a presença ou ausência de êmbolos nas artérias principais, lobares, segmentares e subsegmentares dos 50 pacientes em cada uma das reconstruções MIP, as quais foram comparadas usando-se a reformatação MPR de 1 mm como padrão de referência. RESULTADOS: As reconstruções MIP de 2 mm tiveram melhor acurácia, estatisticamente significativa, em relação a MIP de 4 mm, com valores de sensibilidade 100,0 e 100.0 para as artérias principais e lobares; 92,6 e 85,5 para as segmentares e 94,3 e 86,8 para as subsegmentares. Utilizando as imagens multiplanares de 1 mm como referência padrão. Todos pacientes com TEP foram detectados com imagens em MIP de 2 mm. Dois pacientes com TEP não foram diagnosticados com imagens em MIP de 4 mm. Não houve diferença estatisticamente significativa entre a reformatação MIP de 2 mm e 2 mm + PRM na detecção de êmbolos. CONCLUSÃO: Com um número de imagens equivalente a metade da reconstrução MPR de 1 mm, a reconstrução em MIP de 2 mm conseguiu detectar todos os pacientes com TEP positivo que foram diagnosticados pelas imagens multiplanares de 1 mm, com sensibilidade de 100,0 e 100,0 nas artérias principais e lobares, de 92,6 e 85,5 para as artérias segmentares e 94,3 e 86,8 para as artérias subsegmentares. O acréscimo de reformatações PRM às imagens em MIP de 2 mm não aumentou a acurácia na detecção de êmbolos, mas melhorou a visualização da continuidade dos êmbolos, principalmente, nas artérias centrais. / INTRODUCTION: Multidetector computed tomography (MDCT) has been making possible the increase of the sensibility in the detection of the pulmonary embolism (PE). It is observed, however, that there is a substantial increase in the number of images and, consequently, in the time of analysis for the radiologist. A possible solution to this problem is accomplishing a maximum intensity projection reconstruction (MIP) that reduces the number of images for analysis. Still, there is a new image modality using MIP reconstructions in rotational plans that pivot on a central horizontal axis between the lung hila (paddlewheel reformations, PDW). It provides a continuous display of branching arteries that radiate from both hila. However, studies are necessary to determine if the use of multiplan MIP reformation can reduce the number of images to be analyzed, without significant loss of information; and, if the addition of PDW reformation can improve the diagnosis of PE. OBJECTIVE: To test the hypothesis that images using maximum intensity projection reconstructions of 2,0 mm and 4,0 mm of thickness, multiplan, have the same diagnosis value for detection of pulmonary embolism in the big and small pulmonary arteries, when compared to multiplan images of 1 mm collimation, accomplished in 16 and 10 slice MDTC; and to evaluate if there is influence on the diagnosis value of PE the increment of PDW reformation, in the images rebuilt in MIP of 2 mm. CASUISTIC AND METHODS: Fifty patients suspected of having an acute PE (30 with positive PE and 20 with negative PE, detected during the tomography exam) accomplished computerized tomography of the thorax for evaluation of the pulmonary arteries by 16 and 10 slice MDTC (120 kV, 200 mAs and 1 mm collimation). Four kind of images series (1 mm thick multiplan images and 3 kinds of reconstructed images using the MIP tecnhnique with slab thicknesses of 2 mm, 4 mm and 2 mm added of PDW reformation) were obtained from each exam. Two observers independently evaluated, in work station, the presence or absence of emboli in the main and lobar, segmental and subsegmental arteries in the 50 patients in each one of the reconstructions in MIP, which they were compared using the reformation of 1 mm of thickness as reference pattern. RESULTS: The reconstructions in MIP of 2 mm had better accuracy than MIP of 4 mm, statistically significant with values of sensibility 100,0 and 100,0 for the main and lobar pulmonary arteries; 92,6 and 85,5 for the segmental and 94,3 and 86,8 for the subsegmental. The images in MPR of 1 mm were used as a reference pattern. All patients with PE were detected with images in MIP of 2 mm; two patients with PE were not diagnosed with images in MIP of 4 mm. There was not difference statisticament significant among reformation in MIP of 2 mm and 2 mm plus PDW in the detection of emboli. CONCLUSION: Reconstruction in MIP of 2 mm reduced the number of images for the half and it detected all patients with positive PE that were diagnosed by the multiplans images of 1 mm, with sensibility of 100,0 and 100,0 in the main and lobar arteries, of 92,6 and 85,5 and 79,2 for the segmental arteries and 94,3 and 86,8 for the subsegmental arteries. The increment of PDW reformation to the images in MIP of 2 mm didn\'t increase the accuracy in the detection of emboli, but it improved the visualization of the continuity of the emboli, mainly, in the central arteries.