A aterosclerose é um processo inflamatório crônico e sistêmico, responsável pelo surgimento de eventos cardiovasculares, uma alteração precoce na aterosclerose é a disfunção endotelial. Fatores de risco clássicos, em geral, associam-se a aterosclerose. Porém, cerca de 35% dos coronariopatas não apresentam estes fatores. Estudos têm relacionado concentrações baixas de HDL-C com coronariopatia e disfunção endotelial. Sabe-se também que a lipemia pós-prandial está relacionada alterações na cinética de quilomícrons (QM) e associa-se à doença coronária. Nossa hipótese foi que concentrações baixas de HDL-C, isoladamente, estariam associadas a disfunção endotelial e a diminuição da remoção de remanescentes de quilomícrons; e que o tratamento com niacina de liberação lenta poderia reverter estes efeitos. Estudamos 30 pacientes com HDL-C inferior a 40 mg/dl e 11 controles. Avaliamos a função endotelial por ultra-sonografia de alta resolução da artéria braquial aferindo a dilatação mediada pelo fluxo (DMF) e pela dilatação mediada pelo nitrato (DMN). Avaliamos também a cinética de quilomícrons utilizando a técnica de clearence de quilomícrons artificiais. Idade e altura foram similares em ambos os grupos, porém os pacientes do grupo HDL-C Baixo apresentavam maior peso, IMC e circunferência abdominal. Os pacientes do grupo HDL-C Baixo apresentaram concentrações mais baixas de HDL-C (34,3 +/- 4,6 vs. 50,6 +/- 11,7 mg/dl), p < 0,001. As concentrações de Colesterol Total e LDL-C foram semelhantes em ambos os grupos porém, as concentrações basais de triglicérides e glicemia foram mais elevadas no grupo HDL-C Baixo (113,1 +/- 43,9 vs. 78,9 +/- 35,1; e 96,2 +/- 8,6 vs. 89,9 +/- 7,8), p<0,02 e <0,05 respectivamente. A DMF e a taxa de remoção fracional de colesterol éster (TRF-CE) foram menores no grupo HDL-C Baixo (7,4 +/- 4,1 vs. 12,8 +/- 4,6%; e 0,0036 +/- 0,0051 vs. 0,0122 +/- 0,0084 0,0036 +/- 0,0051min-1), p < 0,001 e < 0,008 respectivamente; a DMN e a taxa de remoção fracional de triglicérides (TRF-TG) foram similares. Os 22 pacientes apresentaram DMF diminuída (< 8 %) e foram divididos aleatoriamente em 2 grupos de 11 indivíduos. Um grupo recebeu 1,5 g/dia de niacina de liberação lenta e o outro placebo. Após 3 meses de tratamento os pacientes do grupo niacina apresentou normalização da DMF que aumentou de 5,44 +/- 1,89% para 11,13 +/-3,4%, p <0,01. Os demais parâmetros não se alteraram em ambos os grupos. Baixas concentrações de HDL-C associaram-se a disfunção endotelial, pela menor DMF, e a menor TRF-CE, ou seja maior permanência de RQM. A niacina corrigiu a disfunção endotelial sem agir nas concentrações lipídicas ou na cinética de lípides / Atherosclerosis is a chronic and systemic inflammatory process that causes the cardiovascular disease. Classical risk factors are, in general, associated to atherosclerosis; however about 35% of the patients do not have those factors. Low HDL-C has been associated to coronary artery disease (CAD) and endothelial dysfunction. Postprandial lipemia is related to changes in chylomicron kinetics and are also related to CAD. Our hypothesis were that low HDL-C would be associated to endothelial dysfunction and slower clearence of chylomicron and remnants; and that treatment with slow release niacin could revert those abnormalities. We studied 30 men with 40 mg/dl or less of HDL-C and 11 controls. We used high resolution ultrasonography on the brachial artery to evaluate flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) to estimate the flow independent dilation. We also assessed chylomicron kinetics trough the chylomicron-like emulsion clearence technique. Both groups were comparable regarding age, height and total cholesterol and LDL-C concentrations. The low HDL-C group had higher weight, body mass index, abdominal circumference and triglycerides and glucose concentrations (113.1 +/- 43.9 vs. 78.9 +/- 35.1; and 96.2 +/- 8.6 vs. 89.9 +/- 7.8), p<0.02 and <0.05 respectively. This group also had lower concentrtions of HDL-C (34.3 +/- 4.6 vs. 50.6 +/- 11.7 mg/dl, p < 0.001) as expected. The FMD and the cholesterol ester fractional clearence (CEFC) were reduced in the low HDL-C group (7.4 +/- 4.1 vs. 12.8 +/- 4.6%; and 0.0036 +/- 0.0051 vs. 0.0122 +/- 0.0084 vs. 0.0036 +/- 0.0051min-1, p < 0.001 and < 0,008 respectively). The NMD and the triglycerides fractional clearence were similar in both groups. Twenty two low HDL-C patients had a reduced FMD (< 8%) and were randomized in 2 groups of eleven. 1.5 g/day of niacin were given to the first group while the other received placebo. After 3 months the niacin treated patients showed a normalization of FMD (from 5.44 +/- 1.89 to 11.13 +/-3.4%, p <0,01) while the placebo group had no changes (from 5.21 +/- 2.07 vs. 5.69 +/- 2%) . The other variables remained unmodified. In conclusion, low concentrations of HDL-C were associated with endothelial dysfunction and slower chylomicron clearence. Niacin corrected the endothelial dysfunction without affecting the lipids concentration or chylomicron kinetics

Os objetivos deste estudo são: 1) avaliar a capacidade de se demonstrar, através da ultra-sonografia, microcalcificações agrupadas, previamente identificadas pela mamografia. 2) identificar parâmetros mamográficos dos agrupamentos de microcalcificações e correlacionar com a positividade da ultra-sonografia na caracterização destas lesões. 3) avaliar a possibilidade de a ultra-sonografia mamária servir de guia de biópsias dirigidas, através de agulha grossa (biópsia percutânea de fragmento - \"core biopsy\"), nestas lesões. Entre dezembro de 2000 e abril de 2002, foram avaliadas através da ultra-sonografia, 68 pacientes com 70 focos de microcalcificações agrupadas na mamografia, suspeitas para neoplasia maligna, classificadas segundo critério de BI-RADSTM nas categorias 4 e 5, sem outras alterações mamográficas associadas, como distorções ou massas. Características das lesões na mamografia, como tamanho e profundidade do foco, foram avaliadas e os exames ultra-sonográficos foram classificados como positivos, quando as microcalcificações foram claramente identificadas e, negativos, quando não identificadas. Nas lesões positivas foram realizadas biópsias percutâneas de fragmento (\"core biopsy\"), através da ultra-sonografia e radiografia dos fragmentos. Nas negativas, os procedimentos foram guiados pela esterotaxia. Características ultra-sonográficas das lesões positivas foram analisadas e resultados anatomopatológicos foram correlacionados. Dos 70 focos de microcalcificações, 26 foram identificados através da ultra-sonografia (37,1%), sendo submetidas a biópsias guiadas pela ultra-sonografia e 44 não foram identificadas (62,9%). O tamanho médio dos focos de microcalcificações foi significativamente maior nos casos positivos ao ultra-som - 14,0 mm, em relação aos negativos - 7,6 mm (p< 0,001). Na avaliação da profundidade dos focos, a identificação positiva pela ultra-sonografia foi significativamente maior nos casos de lesões no terço anterior, mais superficiais (16/26 - 61,5%) em relação às intermediárias (8/26 - 30,8%) e nas posteriores, mais profundas (2/26 - 7,7%) - Chi Square (p< 0,002). Avaliando as características ultra-sonográficas dos achados, em 6 identificou-se massa associada (6/26 - 23,1%), Nas outras, foram identificados pontos hiperecogênicos em meio ao tecido adiposo em 13 (13/26 - 50%); na parede de cistos em 5 (5/26 - 19,2%) e no interior de ductos em 2 (2/26 - 7,7%). Foram diagnosticados 12 casos de câncer, sendo que 8 foram identificados através da ultra-sonografia (8/12 - 66,7%) e 4 não (4/12 - 33,3%). Das 26 biópsias orientadas pela ultra-sonografia, em 18 delas (18/26 - 69,2%) foram identificadas microcalcificações nas radiografias dos fragmentos e em 8 não (8/26 - 30,8%). Nos 8 casos positivos para câncer, o diagnóstico foi subestimado em 3 delas (37,5%) em comparação com resultado anatomopatológico final da cirurgia. A ultra-sonografia apresenta uma sensibilidade baixa na identificação de focos de microcalcificações, previamente vistos na mamografia. O diâmetro médio dos focos de microcalcificações identificados na ultra-sonografia é maior do que nos não identificados. A ultra-sonografia identifica melhor focos de microcalcificações situados no terço anterior da mama, mais superficiais, em números percentuais maiores que no intermediário e posterior. A identificação de focos de microcalcificações ao ultra-som permite que biópsias de fragmento sejam realizadas, orientadas por este método / The present study aims to (1) evaluate sonographic ability of demonstrating clustered microcalcifications previously detected on mammographic examination, (2) demonstrate mammographic patterns of clustered microcalcifications and its correlation to sonographic characterization of lesions, and (3) evaluate clinical feasibility of using ultrasound-guided core biopsy of suspicious microcalcifications. Sixty eight patients with 70 clusters of mammographically detected suspicious microcalcifications - classified as category 4 or 5 according to ACR BI-RADS(TM) - and without associated findings, such as architectural distortions or nodules, underwent sonographic examination between December/2000 and April/2002. Examinations were considered positive when microcalcifications were clearly demonstrated and negative otherwise. In the former, ultrasound-guided core biopsy was performed, including specimen radiograph, and sonographic findings were correlated to histopathological results. In the latter, patients underwent stereotactic biopsy. Among 70 clusters of microcalcifications, 26 were demonstrated on sonography (37,1%) and these patients underwent ultrasound-guided core biopsy, while 44 lesions were not detected on sonographic examination (62,9%). The median size of lesions seen on sonography was significantly greater - 14.0 mm -, in contrast to the median size of lesions not detected - 7.6 mm (p<0.001). Considering the location of microcalcifications, sonographic detection of lesions was significantly more frequent in patients with microcalcifications in the anterior third of breast parenchyma (16/26 - 61.5%), when compared to those in the mid third (8/26 - 30.8%) and posterior third (2/26 - 7.7%) (p<0.002). Cancer was demonstrated in 12 patients, 8 of them using ultrasound-guided biopsy (8/12 - 66.7%) and 4 using stereotactic biopsy (4/12 - 33.3%). Microcalcifications were demonstrated on specimen radiographs in 18 out of 26 ultrasound-guided core biopsies (18/26 - 69.2%), and it was not possible to detect them on specimen radiographs in 8 patients (8/26 - 30.8%). Between 8 patients with cancer demonstrated using ultrasound-guided core biopsy, diagnosis was underestimated in 3 (37.5%), in comparison to 1 patient out of 4 (25%) who underwent stereotactic biopsy. Sonographic examination has low sensitivity in detection of clustered microcalcifications previously seen on mammography. The median diameter of lesions demonstrated on sonography is greater than that of microcalcifications not detected. Clusters of microcalcifications in the anterior third of breast parenchyma were also detected more frequently than lesions situated more posteriorly. Sonographic detection of clustered microcalcifications allows performing ultrasound-guided core biopsy

Objetivo: Estudar os componentes refrativos da hipermetropia em crianças com ambliopia por esotropia, comparando os olhos amblíopes com os olhos contralaterais. Métodos: Foram incluídos 37 pacientes de 5 a 8 anos de idade, com hipermetropia bilateral e ambliopia por esotropia. Foi realizada avaliação oftalmológica completa, incluindo refratometria sob cicloplegia, ceratometria e biometria ultrassonográfica modo A. Foram registrados profundidade da câmara anterior, espessura do cristalino, profundidade da câmara vítrea e comprimento axial total. O poder refrativo do cristalino foi calculado pelas equações de Bennett. Para comparar erro refrativo, poder da córnea, poder calculado do cristalino e componentes ecobiométricos entre os olhos amblíopes e os olhos contralaterais foi empregado o teste t de Student pareado. Para avaliar a relação entre os principais componentes refrativos individuais e o erro refrativo foram empregados o coeficiente de correlação de Pearson e a análise de regressão linear. Foram construídos também modelos multivariados, incluindo comprimento axial, poder da córnea e poder do cristalino. Resultados: Os olhos amblíopes apresentaram hipermetropia mais alta, menor poder da córnea, maior poder do cristalino, menor profundidade da câmara vítrea e menor comprimento axial. Não houve diferença entre os olhos quanto à profundidade da câmara anterior ou à espessura do cristalino. A variável que apresentou correlação mais forte com o erro refrativo foi a razão comprimento axial/raio de curvatura da córnea (r = -0.92, p < 0.001 nos olhos amblíopes e r = - 0.87, p < 0.001 nos olhos contralaterais). O comprimento axial representou 39,2% da explicação da variabilidade do erro refrativo nos olhos amblíopes e 35,5% nos olhos contralaterais. O modelo que combinou comprimento axial e poder da córnea explicou 85,7% e 79,6% da variabilidade do erro refrativo, respectivamente. Houve correlação significante entre comprimento axial e poder da córnea, indicando diminuição do poder da córnea com o aumento do comprimento axial e os coeficientes de correlação foram semelhantes entre os olhos amblíopes (r = -0.53, p <0.001) e os olhos contralaterais (r = -0.57, p < 0.001). Houve correlação significante entre comprimento axial e poder do cristalino, indicando diminuição do poder do cristalino com o aumento do comprimento axial e os coeficientes de correlação também foram semelhantes entre os olhos amblíopes (r = -0.72, p < 0.001) e os olhos contralaterais (r = -0.69, p < 0.001). Conclusão: As correlações entre os principais componentes refrativos e sua contribuição individual para o erro refrativo foram semelhantes nos olhos amblíopes e nos olhos contralaterais de crianças com esotropia, a despeito da hipermetropia mais alta nos olhos amblíopes / Purpose: To study the refractive components of hyperopia in children with esotropic amblyopia, comparing amblyopic eyes with fellow eyes. Methods: Thirty-seven patients (5 to 8 years old) with bilateral hyperopia and esotropic amblyopia underwent a comprehensive ophthalmic examination, including cycloplegic refraction, keratometry and A-scan ultrasonography. Anterior chamber depth, lens thickness, vitreous chamber depth and total axial length were recorded. The refractive power of the crystalline lens was calculated using Bennett`s equations. Paired Students t-tests were used to compare refractive error, corneal power, calculated lens power and ocular biometric measurements between amblyopic eyes and their fellow eyes. The relationship between the major oculometric parameters and refractive error was assessed using Pearson correlation coefficients and linear regression. Multivariable models including axial length, corneal power and lens power were also constructed. Results: Amblyopic eyes were found to have significantly more hyperopic refraction, lesser corneal power, greater lens power, shorter vitreous chamber depth and shorter axial length, despite similar anterior chamber depth and lens thickness. The strongest correlation with refractive error was observed for the axial length/corneal radius ratio (r = -0.92, p < 0.001 for amblyopic and r = -0.87, p < 0.001 for fellow eyes). Axial length accounted for 39.2% of the refractive error variance in amblyopic eyes and 35.5% in fellow eyes. The combination of axial length and corneal power accounted for 85.7% and 79.6% of the refractive error variance respectively. A significant correlation was found between axial length and corneal power, indicating decreasing corneal power with increasing axial length, and they were similar for amblyopic eyes (r = -0.53, p < 0.001) and fellow eyes (r = -0.57, p < 0.001). A significant correlation was found between axial length and lens power, indicating decreasing lens power with increasing axial length, and they were also similar for amblyopic eyes (r = -0.72, p < 0.001) and fellow eyes (r = -0.69, p < 0.001). Conclusion: The correlations among the major refractive components and their individual contribution to refractive error were similar in amblyopic and non-amblyopic eyes in esotropic children, despite more hyperopic refraction in amblyopic eyes

Objetivo: Avaliar a função gonadal de homens com miopatias inflamatórias idiopáticas (MII). Métodos: Vinte e cinco pacientes com MII foram avaliados e comparados com 25 homens saudáveis. Os pacientes foram subdivididos em dois sub-grupos de acordo com as alterações dos espermatozóides: grupo A (n=10, duas ou mais das seguintes alterações: terato/oligo/astenozoospermia ou azoospermia) e grupo B (n=15, teratozoospermia). Foram realizados: exame urológico, ultra-sonografia testicular, análise dos espermatozóides (critérios da OMS e Kruger), pesquisa dos anticorpos anti-espermatozóides e dosagens hormonais Nos subgrupos foram também avaliados: Disease Activity Score (DAS), Visual Analogue Scale (VAS), Manual Muscle Testing (MMT), myositis disease activity assessment visual analogue scales (MYOACT), myositis intention to treat activity index (MITAX), Myositis damage index [MDI], enzimas musculares e tratamento. Resultados: Pacientes apresentaram alterações nos espermatozóides comparados com controles com freqüência maior de nível elevado de FSH (20% versus 0%, p=0,05). O sub-grupo A apresentou freqüência e mediana maior do nível de CK (p=0,001 e p=0,001) assim como DAS (p=0,01), VAS (p=0,051), MMT (p=0,003). As medianas dos volumes testiculares foram menores no grupo A (direito, p=0,015 e esquerdo, p=0,025). As medianas dos parâmetros espermáticos foram reduzidas no grupo A [contagem total (p=0,0001); motilidade (p=0,0001); morfologia pela OMS (p=0,0001) e por Kruger (p=0,0001). A mediana de FSH foi elevada (p=0,035) e de androstenediona foi reduzida (p=0,02) no sub-grupo A. Afrequência de ciclofosfamida foi similar nos grupos (30% versus 6%, p=0,26). Conclusões: Atividade da doença foi o principal fator contribuinte para disfunção gonadal. Hipogonadismo hipergonadotrófico pode explicar as alterações anatômicas e funcionais observadas / Objective: To perform a global gonad evaluation in male idiopathic inflammatory myopathies (IIM) patients. Methods: Twentyfive consecutive IIM were compared to 25 age-matched healthy subjects. Patients were subdivided in two groups according to the severity of sperm abnormalities: group A (at least two of the following terato/oligo/asthenozoospermia or azoospermia) and group B (teratozoospermia). Patients and controls underwent a systematic assessment consisting of: urologic examination, testicular ultrasound, semen analysis and hormones. Patients´ serum CK levels, visual analogue scale (VAS), disease activity score (DAS), manual muscle testing (MMT), myositis disease activity assessment visual analogue scales (MYOACT), myositis intention to treat activity index (MITAX), and Myositis damage index (MDI) were evaluated. Results: Several sperm variables were significantly altered compared to controls (p<0.05). The subgroup analysis according to the severity of sperm alterations revealed that the frequency of elevated CK and its median level was significantly higher in group A (p=0.001 and p=0.001), as also was DAS, VAS and MMT (p=0.01; p=0.051 and p=0.03). The median of testicular volumes were lower in group A (right p=0.015 and left p=0.025). All median sperm parameters were lower in group A (total sperm count, p=0.0001; total motile sperm count, p=0.0001; and sperm morphology by Kruger p=0.0001 and WHO p=0.0001). Higher median FSH (p=0.035) and lower median androstenedione levels (p=0.02) were observed in group A. The frequency of cyclophosphamide was similar in both groups (30% vs. 6%, p=0.26). Conclusions: Active disease was the major contributing factor for severe gonad dysfunction. The hypergonadotrophic hypogonadism may explain the anatomical and dysfunctional alterations observed

INTRODUÇÃO: A ultrassonografia (US) e a ressonância magnética (RM) representam os principais métodos de diagnósticos por imagem na avaliação do mecanismo extensor do joelho. Há carência de trabalhos que avaliem por US e RM a presença de alterações no mecanismo extensor de jogadores de futebol assintomáticos. OBJETIVO: Avaliar, por meio de RM e US, o tendão quadríceps e o ligamento patelar de jogadores de futebol assintomáticos e dos participantes do grupo-controle. Identificar se há alterações de imagens ou lesões. Determinar se essas sofrem influências pelos seguintes critérios: canhoto ou destro, quanto à dominância ao chute, posição em campo, idade do atleta e tempo de prática esportiva. MÉTODO: Foram avaliados um total de 248 joelhos: 112 eram de 56 de jogadores de futebol assintomáticos e 136 eram do grupo-controle. O grupo composto por jogadores de futebol apresentava idades entre 14 e 34 anos. Já o grupo-controle era composto por indivíduos com idade também entre 14 e 34 anos, principalmente, universitários e funcionários do hospital, com gênero igual aos dos jogadores selecionados, mas sem atividades físicas de impacto, como vôlei, futebol e salto, por exemplo. RESULTADO: Constatou-se a presença de alterações de imagens ou de lesões em nove ligamentos patelares e apenas duas nos tendões quadríceps de jogadores de futebol assintomáticos, tanto pela US quanto pela RM, e nenhum caso alterado no grupo-controle. Houve concordância significativa entre RM e US quanto aos resultados obtidos. Além disso, os jogadores de futebol apresentaram anormalidades (alterações de imagens ou lesões) no tendão quadríceps ou no ligamento patelar significativamente (p<0,05) maior do que no grupo-controle; a idade média dos jogadores com alguma anormalidade é significativamente menor do que a dos jogadores sem lesão (p<0,003); o tempo médio de prática desportiva dos jogadores que apresentam anormalidade é menor do que o tempo médio dos jogadores que não têm anormalidade (p<0,001); os jogadores destros apresentaram anormalidades, enquanto que os jogadores canhotos não (p<0,05). Dentre os jogadores, há correlação entre mais alterações de imagem ou lesão de joelho e menor tempo como jogador e menor idade (R² de Nagelkerke = 0,700). Destros têm risco aumentado de ter anormalidade nas referidas estruturas (Razão de Chances = 15,204) quanto menor for o tempo como jogador de futebol. Os jogadores da defesa têm 4,76 vezes mais chance de desenvolver anormalidade do que atacantes e goleiros (p<0,04). CONCLUSÃO: Os jogadores de futebol assintomáticos apresentam anormalidades no tendão do quadríceps e ligamento patelar detectadas pela RM e US. As alterações estão relacionadas a menor idade, menor tempo de prática desportiva, ser destro e ser jogador de defesa / INTRODUCTION: Ultrasonography (US) and magnetic resonance imaging (MRI) are the main diagnostic imaging methods used in evaluation of the extensor mechanism of the knee. Theres a scarcity of works assessing alterations on the extensor mechanism of the knee of asymptomatic soccer players using US and MRI. OBJECTIVE: To assess, by means of MRI and US imaging, the quadriceps tendon and patellar ligament of asymptomatic soccer players and healthy control group; identify abnormal imaging findings or injuries; ascertain whether these are affected by leg dominance (left or right), field position, age, and time spent practicing the sport. METHOD: A total of 248 knees were evaluated: 112 of 56 asymptomatic soccer players and 136 of healthy controls. The players ages ranged from 14 to 34 years. The control group was composed mostly of college students and hospital staff members, also with ages between 14 and 34, matched for gender to the selected soccer players, and who did not engage in high-impact activities such as volleyball, soccer, or jumping. RESULTS: Abnormal imaging findings or injuries were detected, by US and MRI alike, in nine patellar ligaments and two quadriceps tendons of asymptomatic soccer players. No abnormal findings were detected in the control group. CONCLUSION: There was significant consistency between MRI and US findings. Soccer players were much more likely (p<0.05) to have abnormal imaging findings or injuries of the quadriceps tendon and patellar ligament as compared with the control group; the average age of players presenting some abnormality is significantly lower than of those without injuries (p<0.003); the average time spent practicing the sport for players presenting abnormalities is lower than those who dont present injuries (p<0.001); a correlation between the dominant leg and the affected knee was observed, with the players with a dominant right leg presenting injuries while the ones with a dominant left leg not showing abnormalities (p<0.05). Amongst the players there is a correlation between more abnormal imaging findings or injuries on the knee and less professional practicing time and age (Nagelkerke R² = 0.700).Players with a dominant right leg have an increased chance of presenting abnormalities on the quadriceps tendon and patellar ligament (Odds Ratio = 15.204) with a lower average time spent practicing the sport. Defense players have 4.76 times more chance to develop abnormalities than forward players and goalkeepers (p<0.04). CONCLUSION: The asymptomatic soccer players present abnormalities on the quadriceps tendon and patellar ligament identified using ultrasonography (US) and magnetic resonance imaging (MRI). The alterations are related with less age, less time of professional practice, right leg dominance and defense field position

由線性彈性模型引起的多維系數反問題在很多範疇都有其應用，如斷層探測、油田檢測、鹽石檢測、礦石檢測及醫療成像等。瞬時成像技術是其中最有用的應用。它提供了一個快速及安全的醫療成像技術，可以用來檢測在身體內快速移動的器官的一些異常組織，如肝腫瘤。在這篇論文中，我們會重點討論兩個解決瞬時弹性成像反問題的數值方法，即水平集反演方法和近似全局收斂方法。我們會研究這兩種方法的推導和數值結果。 / 特別地，近似全局收斂方法是一種由Klibanov 新提出用來解決由雙曲偏微分引起的多維系數反問題的方法。因為這佪方法沒有使用求泛函極小值的步驟，因此能避免了一些眾所周知的問題，所以它特別穩定。數值結果顯示近似全局收斂方法對噪聲有很高的穩定性。這表明近似全局收斂方法是一個解決由線性彈性模型引起的多維系數反問題的其中一個有效方法。 / Multi-dimensional coefficient inverse problem (MCIP) in linear elasticity has found many applications, such as crack detection, oil/salt/ore detection, medical imaging. Transient elastography is among one of the most useful applications, providing a fast and safe medical imaging technique which can be used to detect tumors or abnormal tissue in “fast-moving“ organs such as the liver. In this thesis focus is casted on two of the numerical algorithms to solve inverse problems related to transient elastography, namely the level-set inversion method and the approximate globally convergent method. The derivations of both methods and numerical results are presented. In particular, the approximate globally convergent method is a newly developed stable method to solve coefficient determination inverse problem for hyperbolic partial differential equation proposed by Beilina and Klibanov in [6]. It achieves pproximately a global convergence by avoiding construction of a least squares functional, thus averting some of the well-known problems of trapping in the neighborhoods of local minima when one minimizes such a nonlinear functional. The results of the approximate globally convergent method have shown its strong stability and robustness. This suggests a good way for the reconstruction of the distribution of the shear modulus in the coefficient inverse problem of linear elasticity. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chow, Yat Tin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 98-102). / Abstracts also in Chinese. / Chapter 1 --- Introduction --- p.6 / Chapter 2 --- Linear Elasticity Model --- p.9 / Chapter 2.1 --- Introduction to Linear Elasticity Model --- p.9 / Chapter 2.2 --- Physical Meanings of Elasticity Equation --- p.12 / Chapter 2.3 --- Derivations of Linear Elasticity Equation --- p.14 / Chapter 2.4 --- Discussion of Christoffel’s Equation --- p.17 / Chapter 3 --- Formulations of the Forward and Inverse Problem --- p.27 / Chapter 3.1 --- The Forward Problem --- p.29 / Chapter 3.2 --- The Inverse Problem --- p.29 / Chapter 3.3 --- A Uniqueness Result --- p.30 / Chapter 4 --- Algorithms for Inverse Problems in Elasticity --- p.33 / Chapter 5 --- Level Set Inversion Method --- p.37 / Chapter 5.1 --- Arrival Time Acquisition: Cross-Correlation --- p.37 / Chapter 5.2 --- The Distance Inversion Method --- p.41 / Chapter 5.3 --- Solving the Forward Eikonal Equation --- p.43 / Chapter 5.3.1 --- Discretizing the eikonal equation --- p.43 / Chapter 5.3.2 --- A forward eikonal solver: fast marching algorithm --- p.47 / Chapter 5.3.3 --- A forward eikonal solver: fast sweeping algorithm --- p.50 / Chapter 5.4 --- Level Set Inversion Scheme --- p.54 / Chapter 5.5 --- Numerical Implementation --- p.57 / Chapter 5.6 --- Results of Reconstructions --- p.58 / Chapter 6 --- Approximate Globally Convergent Method --- p.63 / Chapter 6.1 --- The Forward Problem --- p.65 / Chapter 6.1.1 --- Forward problem in time domain --- p.65 / Chapter 6.1.2 --- Forward problem in Laplace domain --- p.67 / Chapter 6.2 --- The Inverse Problem --- p.67 / Chapter 6.2.1 --- Inverse problem in time domain --- p.67 / Chapter 6.2.2 --- Inverse problem in Laplace domain --- p.68 / Chapter 6.3 --- A Nonlinear Integral Differential Equation --- p.69 / Chapter 6.4 --- Approximation of the First Tail --- p.71 / Chapter 6.5 --- The Algorithm --- p.72 / Chapter 6.6 --- Notes About the Convergence Analysis --- p.76 / Chapter 6.6.1 --- Approximate global convergence --- p.76 / Chapter 6.6.2 --- Basic formulation of Theorem 2.9.4 of [6] --- p.78 / Chapter 6.6.3 --- Some ideas of the convergence analysis for the algorithm in section 6.5 --- p.80 / Chapter 6.7 --- Numerical Implementation --- p.81 / Chapter 6.8 --- Results of Reconstructions --- p.88 / Chapter 7 --- Conclusions --- p.96 / Bibliography --- p.98

在各种临床应用广泛使用的诊断和治疗工具中，超声成像是其中的一个。与其他成像模式相比，比如计算机断层照相法和磁共振成像，超声波检查法有许多优点:没有辐射风险，设备价格低以及能够实时获取图像。很多超声应用的第一步通常是对感兴趣组织和结构的检测和定位。然而，超声图像存在一些特有的伪影，比如高噪声，低信噪比和灰度不均，这些伪影使得检测任务变得困难。此外，感兴趣区域之间的低对比度也使得这一任务变得更加复杂。在这篇论文里，我们深入研究这些图像伪影并提出新的方法来促进临床中的超声应用。 / 首先，我们提出一个多尺度的框架来进行超声图像的分割，这个框架是基于各向异性去噪扩散和测地主动轮廓线的。各向异性去噪扩散是对边缘敏感且专门用于斑点噪声图像的扩散过程，这里它被用来去除超声图像的斑点噪声，我们对每幅输入图像构造一个多尺度的表示方法，随着尺度的增加，噪声被逐渐地消除。之后，多尺度测地主动轮廓线从粗到细渐进地应用到这些尺度来提取物体的边界线。为了避免在低对比度区域出现边界泄漏的情况，我们把不同尺度之间的边界形状相似性结合到传统的测地主动轮廓线模型里作为一个外部约束来指导轮廓线的演化。在合成和临床图像的实验结果证明了我们的方法的优越性。 / 其次，我们提出一个基于相位的方法来检查和测量超声图像里的胎儿腹部轮廓线。我们定义了一个基于局部相位的度量来检测胎儿腹部的边界线，这个度量称为多尺度特征非对称性，它与图像的亮度无关，并且能为图像里特征的重要程度提供一个绝对的测量。为了估计与腹部轮廓线相吻合的椭圆，我们使用一个迭代随机霍夫变换来排除内腹部边界线的影响，从而使得估计的椭圆逐渐收敛到外边界线。在临床超声图像里进行腹部周长测量的实验结果验证了我们的方法与手工的方法有很高的一致性，这也表明我们的方法可以作为一个可靠的工具来进行产科的护理和诊断。 / Ultrasound imaging is one of the most widely used diagnostic and therapeutic tools for a variety of clinical applications. Compared with other imaging modalities, such as computed tomography and magnetic resonance imaging, ultrasonography has a lot of advantages: free of radiation risk, low cost of acquisition and images are available in real-time. The first step in many ultrasonic applications is usually the detection and localization of interested tissues and structures. However, there are a number of characteristic artifacts in ultrasound images that make the task difficult such as high speckle noise, low signal-to-noise ratio and intensity inhomogeneity. Besides, the low contrast between regions of interest further complicates the processing. In this thesis, we deeply investigate these image artifacts and propose new techniques to facilitate ultrasonic applications in clinic. / First, we propose a multiscale framework for ultrasound image segmentation based on speckle reducing anisotropic diffusion(SRAD) and geodesic active contours (GAC). SRAD is an edge-sensitive diffusion tailored for speckled images, and it is adopted here to reduce speckle noise by constructing a multiscale representation for each input image, where the noise is gradually removed as the scale increases. Multiscale geodesic active contours are then applied along the scales in a coarse-to-fine manner to capture the object boundaries progressively. To avoid boundary leakages in low contrast regions, traditional GAC model is modified by incorporating the boundary shape similarity between different scales as an external constraint to guide the contour evolution. Experimental results in both synthetic and clinical images demonstrate the superiority of the proposed approach. / Second, we propose a phase-based approach for fetal abdominal contour detection and measurement in ultrasound images.We define a local phase-based measure, called multiscale feature asymmetry (MSFA), from the monogenic signal to detect the boundaries of fetal abdomen. The MSFA measure is intensity invariant and provides an absolute measurement for the significance of features in the image. In order to estimate the ellipse that fits to the abdominal contour, we employ an iterative randomized Hough transform to exclude the interferences of the inner boundaries of the abdomen, after which the estimated ellipse gradually converges to the outer boundaries. Experimental results in clinical ultrasound images validate the high agreement between our approach and manual approach in the measurement of abdominal circumference, indicating that the proposed approach can be used as a reliable tool for obstetric care and diagnosis. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wang, Weiming . / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 68-84). / Abstracts also in Chinese. / Wang, Weiming .

TITLE: IN VIVO ANTRAL FOLLICLE WALL BIOPSY: A NEW RESEARCH TECHNIQUE TO STUDY OVARIAN FUNCTION USING THE HORSE AS A MODEL Abstract Understanding hormone and growth factor receptor expression in the follicular wall associated with the intrafollicular milieu and systemic endocrine aspects in vivo is crucial for a complete discovery of mechanisms behind folliculogenesis in different species. Furthermore, the comprehension of the interrelationships existent among the preovulatory follicle (POF) and corpus luteum (CL) diameter and blood flow, and progesterone (P4) production during different seasons of the year are warranted to optimize fertility in different species. In this dissertation, four studies in mares are presented with the following general objectives: (i) develop and validate a minimally invasive in vivo technique to obtain antral follicle wall biopsy (FWB) and follicular fluid (FF) samples simultaneously and repeatedly from the same individuals, during different stages of follicle development in different seasons of the year; (ii) use the FWB technique to elucidate and compare the expression pattern of different receptors and proteins involved in folliculogenesis and ovulatory mechanisms during different seasons of the year; and (iii) use B-mode and color Doppler ultrasonography techniques to characterize POF and CL diameter and blood flow during two transitional ovulatory seasons (spring and fall), and elucidate the interrelationships among these variables with systemic P4 concentration. In the first study (Chapter 2), two experiments were conducted; in Experiment 1 (ex vivo), a proof of concept study was developed to check the feasibility of using the biopsy forceps to harvest FWB samples. Ovaries of six slaughtered mares were used, and each follicle was sampled using two techniques: biopsy forceps and scalpel blade (control). In Experiment 2 (in vivo), FWB and FF samples from growing follicles during various developmental stages were harvested using a novel FWB transvaginal ultrasound-guided technique. In the second study (Chapter 3), antral follicle wall and FF samples were obtained from 10−, 20−, and 30−mm follicles during spring anovulatory (SAN) and spring ovulatory (SOV) seasons. Samples were collected in vivo from the same mares in both seasons, with the aims to study and compare the expression of proliferative, angiogenic, and pro-/anti-apoptotic receptors and proteins in the follicle wall among three follicle classes, and between the SAN and SOV seasons. In the third study (Chapter 4), FWB and FF samples were collected in vivo from dominant growing follicles during the SAN, SOV, summer (SU), and fall ovulatory (FOV) seasons, to study the expression patterns of different receptors and proteins involved in follicle development. In the fourth study (Chapter 5), the temporal relationships among diameter and blood flow of the POF and CL, and systemic P4 concentration during spring and fall transitional ovulatory seasons were studied. The main findings of the present studies were: (i) the histological appearance, organization, and thickness of the follicle wall layers (i.e. granulosa, theca interna, and theca externa) were not influenced by the harvesting techniques (biopsy forceps vs. scalpel blade); (ii) the overall recovery rates of FWB and FF samples were 97% and 100%, respectively. However, the success rate of obtaining samples with all layers of the follicle wall and clear FF varied according to follicle size; (iii) follicles of the SOV season had a higher expression of proliferative, angiogenesis, and anti-apoptotic proteins compared to the SAN season; (iv) follicles of the FOV season had lower expression of proliferative, angiogenesis, and luteinizing hormone receptors; and (v) positive correlations were observed among POF and CL parameters, and P4 concentration. In conclusion, results demonstrated that the novel in vivo FWB technique developed in this study can be repeatedly and simultaneously used to provide sufficient FWB and FF samples for various cellular and molecular studies without jeopardizing the ovarian function in mares. Furthermore, results presented herein showed that several proliferative, angiogenic, and pro-/anti-apoptotic proteins are differentially expressed within different layers of the antral follicle wall among different seasons of the year. Finally, results demonstrated that larger and well-vascularized POFs have the potential to produce larger CLs with greater blood flow, and subsequently greater P4 systemic levels.

A asfixia perinatal e sua mais grave complicação, a encefalopatia hipóxicoisquêmica (EHI) são causas de elevada mortalidade e de sequelas neurológicas no recém-nascido (RN). Evidencias de comprometimento cerebral podem ser detectadas logo na primeira semana de vida e o diagnóstico precoce é de grande importância para o tratamento e seguimento. OBJETIVOS: Verificar a prevalência de asfixia perinatal e de EHI; analisar a utilidade de quatro marcadores sanguíneos: transaminase glutâmica oxalacética (TGO), transaminase glutâmica pirúvica (TGP), desidrogenasse láctica (DHL) e Creatina Quinase MB (CK-MB) coletados ao nascimento, com 24 e 72 horas de vida, como sinalizadores de lesões cerebrais nos RN asfixiados; identificar a presença de alterações neurológicas clínicas pelo Escore de Sarnat e Sarnat (1976) com 24 e 72 horas e com 28 dias de vida e identificar e descrever a presença de lesões cerebrais detectadas pela ultrassonografia de crânio com 24 e 72 horas e com 28 dias de vida. MÉTODO: Estudo de coorte prospectivo no qual foram incluídos RN de termo que apresentaram asfixia perinatal pelo critério de Buonocore (presença ao nascimento de pelo menos dois das seguintes condições clínico-laboratoriais: acidose metabólica com níveis de pH 7,20, Boletim de Apgar no quinto minuto de vida < 6, necessidade de fração inspirada de oxigênio 0,40 para manter uma saturação de oxigênio de 86%). Para realização do pH e dos marcadores bioquímicos foi coletado sangue logo ao nascimento, com 24 e 72 horas de vida. O exame clínico segundo critérios de Sarnat e Sarnat foi realizado com 24 e 72 horas e com 28 dias de vida e a ultrassonografia de crânio nos mesmos momentos. RESULTADOS: De 2.989 nascidos vivos durante o período do estudo, 28 recém-nascidos apresentaram asfixia perinatal (1% do total de nascimentos) e a EHI foi evidenciada em 21,42%. A enzima CK-MB se mostrou um bom marcador de asfixia, pois todos os valores foram superiores a 5,10 ng/ml, e se correlacionaram positivamente com as alterações apresentadas no exame clínico de Sarnat e com a ultrassonografia transfontanela. Os valores das outras enzimas como TGO (24h), TGO e TGP (72h) também se correlacionaram positivamente com as alterações ultrassonográficas as quais mostraram alteração em 3,5% dos pacientes com 24 horas de vida, 25% com 72 horas e 28,6% com 28 dias. A ultrassonografia de crânio com 28 dias mostrou aumento estatisticamente significante, no percentual de resultados anormais quando comparado com o observado com 24h (p=0,039), apesar dos estágios de Sarnat terem melhorado, com maior número de pacientes com estágio I no decorrer dos 28 dias. CONCLUSOES: A prevalência de asfixia perinatal e da EHI estão dentro da faixa citada na literatura. O melhor marcador bioquímico nesta casuística foi a isoenzima CK-MB e se correlacionou com as alterações apresentadas no exame clínico de Sarnat e na USG de crânio. A curva ROC mostrou: os valores de CK-MB de 24 horas em relação à USG de crânio de 72 horas Sensibilidade de 85,7%, Especificidade de 85,7% e Acurácia de 85,7%. O escore clínico de Sarnat não se alterou depois de 72 horas e apresentou correlação com as alterações na USG de crânio e este método de imagem foi adequado para detecção de lesões crebrais precoces e com 28 dias de vida / Perinatal asphyxia and its most serious complication, hypoxic-ischemic encephalopathy (HIE) are causes of high mortality and neurological sequelae in the newborn (NB). Evidence of cerebral impairment can be detected in the first week of life and early diagnosis is very important for the treatment and follow-up. OBJECTIVES: To assess the prevalence of perinatal asphyxia and HIE; consider the usefulness of four blood markers: glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lactate dehydrogenase (LDH) and creatine kinase MB (CK-MB) collected the birth, with 24 and 72 hours of life, as markers of brain damage in asphyxiated infants, to identify the presence of neurological clinical score by Sarnat and Sarnat (1976) with 24 and 72 hours and 28 days of life and describe the presence of brain lesions detected by cranial ultrasound with 24 and 72 hours and 28 days. METHOD: A prospective cohort study which included fullterm infants who had perinatal asphyxia by Buonocore criteria (presence at birth of at least two of the following clinical and laboratory conditions: metabolic acidosis with pH levels of the umbilical vein 7.20, Apgar score in the fifth minute of life <6, need for inspired oxygen fraction (FiO2) 0.40 to maintain an oxygen saturation of 86%). To perform the pH and biochemical markers of blood was collected at birth, 24 and 72 hours of life. Clinical examination according to criteria of Sarnat and Sarnat was performed with 24 and 72 hours and 28 days of life and cranial ultrasound was performed in the same time. RESULTS: Of 2989 live births during the study period, 28 had asphyxia (1% of total births) and HIE was found in 21.42%. The CK-MB showed that all above normal values (<5.10ng/ml) and correlated with the changes presented in the clinical examination of Sarnat and the USG transfontanelle. The values of other enzymes such as GOT (24h), GOT and GPT (72h) also correlated positively with the brain lesins detected by cranial ultrasound in 3.5% of patients with 24 hours of life, 25% at 72 hours and 28 6% after 28 days. Ultrasonography of brain at 28 days showed a statistically significant increase in the percentage of abnormal results when compared with that observed at 24h (p = 0.039), despite the Sarnat stages have improved, with larger numbers of patients with stage I during the 28 days. CONCLUSION: The prevalence of perinatal asphyxia and HIE is within the range cited in literature. The best biochemical marker in this series was the CK-MB and correlated with the changes presented in the clinical examination of Sarnat and ultrasound transfontanelle. The ROC curve showed: values of CK-MB of 24 hours and USG 72 hours sensitivity of 85.7%, specificity of 85.7% and accuracy of 85.7%. The clinical Sarnat score did not change after 72 hours and correlated with changes in ultrasound transfontanelle and this imaging method proved to be an appropiate study to detect brain lesions early and with 28 days of life

Com o objetivo de caracterizar, do ponto de vista sócio-demográfico, e obter a evolução pós-natal, das gestantes com diagnóstico ultra-sonográfico pré-natal de malformação fetal maior, atendidas no Setor de Medicina Fetal do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, no período de 15/12/2005 a 15/12/2006, foram entrevistadas 335 gestantes. Foram excluídas aquelas que não concordaram em conceder a entrevista e aquelas que não tiveram confirmação da malformação fetal em exame realizado pela equipe de Medicina Fetal. A idade materna média das gestantes foi de 27,1 anos; a cor da pele predominante, parda (48,1%), seguida de branca (35,5%) e negra (16,4%). Em relação à escolaridade, 57,8% das gestantes apresentavam grau de escolaridade igual ou inferior ao ensino médio completo. A renda salarial média foi de 3,1 salários-mínimos. Possuíam planos de saúde privado 19,4% das envolvidas no estudo. Em relação ao uso de medicamentos na gestação, 26,6% referem ter feito uso, sendo que em 5,7% tratava-se de substância abortiva, e 1,2% admitiram ser usuárias de drogas ilícitas durante o 1º trimestre da gestação. Quanto aos antecedentes de malformação fetal, 10,4% das gestantes o referiram, sendo as malformações cardíacas e as síndromes / seqüência as mais comuns (28,6% cada). Dentre os casos de malformação atual, as do sistema nervoso central foram as mais prevalentes (28%), seguidas das malformações renais (9,2%) e cardíacas (8,9%). Foram submetidas a cariótipo fetal 36,7% (123/335) das gestações, sendo 23,6% dos resultados anormais. Em 311 casos (92,8%), o resultado da gestação foi obtido. Destes, 76,8% nasceram vivos; 25,7% evoluíram com óbito neonatal; 16,4% foram natimortos e em 6,3% houve interrupção da gestação. O presente estudo permitiu conhecer as características sócio demográficas e os resultados gestacionais de mulheres com diagnóstico de malformação fetal, o que poderá ser útil para o planejamento periconcepcional deste grupo de pacientes / The purpose of this study is to describe the socio demographic profile and perinatal outcome of pregnant women with prenatal ultrasound diagnosis of major fetal malformation at the Hospital das Clínicas, São Paulo University Medical School. The study was performed from 15th December 2005 to 15th December 2006. Cases that were not confirmed and did not consent to participate in the study were excluded. Mean maternal age was 27.1 years and skin color was brown in 48.1% of the cases (white: 35.5% and black: 16.4%). According to the educational level and salary, 57.8% did not finish college and the mean monthly income was 3.1 minimal wages. 19.4% of the cases had private health insurance coverage. The proportion of women who were taking medications during pregnancy was 26.6%, and from these, 5.7% intended for an abortion. Drug addiction during the first trimester was admitted by 1.2%. A previous history of a fetal malformation was reported by 10.4% of women, most cases were related to cardiac, genetic or environmental syndromes. The central nervous system was the most frequent site of malformation (28.1%), followed by renal (9.3%) and cardiac (9%) defects. Fetal karyotype was determined in 36.7% (123/335) of the fetuses and 23.6% of the results were abnormal. Pregnancy outcome was ascertained in 311 cases (92.8%): 76.8% were alive, 25.7% were neonatal deaths, 16.4% were stillborn and 6.3% miscarried. This study describes social demographic features and perinatal outcome in pregnancies with major fetal malformation diagnosed antenatally. This information is useful for parents preconception counseling