129 resultados para EIT,problema inverso,mal condizionamento,imaging,tomografia elettrica,python
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We report the findings of abdominal ultrasound and magnetic resonance imaging observed in a patient with advanced schistosomiasis mansoni. A 25-year-old man with hepatosplenic schistosomiasis and variceal bleeding confirmed by upper endoscopy was submitted to abdominal ultrasound and magnetic resonance imaging. During surgery for portal hypertension, a liver biopsy was taken and the diagnosis of Symmers' fibrosis was confirmed. magnetic resonance imaging scans gave more precise information about the gallbladder, periportal thickening and abdominal venous system than did the ultrasound.
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INTRODUCTION: There is no study relating magnetic resonance imaging (MRI) to ultrasound (US) findings in patients with Schistosomiasis mansoni. Our aim was to describe MRI findings inpatients with schistosomal liver disease identified by US. METHODS: Fifty-four patients (mean age 41.6±13.5years) from an area endemic for Schistosomiasis mansoni were selected for this study.All had US indicating liver schistosomal fibrosis and were evaluated with MRI performed witha 1.5-T superconducting magnet unit (Sigma). RESULTS: Forty-seven (87%) of the 54 patientsshowing signs of periportal fibrosis identified through US investigation had confirmed diagnosesby MRI. In the seven discordant cases (13%), MRI revealed fat tissue filling in the hilar periportalspace where US indicated isolated thickening around the main portal vein at its point of entryto the liver. We named this the fatty hilum sign. One of the 47 patients with MRI evidence ofperiportal fibrosis had had his gallbladder removed previously. Thirty-five (76.1%) of the other46 patients had an expanded gallbladder fossa filled with fat tissue, whereas MRI of the remainingeleven showed pericholecystic signs of fibrosis. CONCLUSIONS: Echogenic thickening of thegallbladder wall and of the main portal vein wall heretofore attributed to fibrosis were frequentlyidentified as fat tissue in MRI. However, the gallbladder wall thickening shown in US (expandedgallbladder fossa in MRI) is probably secondary to combined hepatic morphologic changes inschistosomiasis, representing severe liver involvement.
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Although cryptococcal infections begin in the lungs, meningoencephalitis is the most frequently encountered manifestation of cryptococcosis among individuals with advanced immunosuppression. As the infection progresses along the Virchow-Robin spaces, these structures may become dilated with mucoid material produced by the capsule of the organism. We report a case of a 24-year-old man with cryptococcal meningoencephalitis in which magnetic resonance imaging showed clusters of gelatinous pseudocysts in the periventricular white matter, basal ganglia, mammillary bodies, midbrain peduncles and nucleus dentatus with a soap bubble appearance.
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The authors report the magnetic resonance imaging diagnostic features in two cases with respectively lumbar epidural hematoma and cavernous hemangioma of the lumbar epidural space. Enhanced MRI T1-weighted scans show a hyperintense signal rim surrounding the vascular lesion. Non-enhanced T2-weighted scans showed hyperintense signal.
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PURPOSE: To determine the consequences of the chronic use of systemic corticosteroids in children with juvenile rheumatoid arthritis by means of evaluating osteochondral effects depicted by magnetic resonance imaging. PATIENTS AND METHODS: We reviewed clinical and magnetic resonance imaging findings in 69 children (72 knees) with juvenile rheumatoid arthritis. Two groups were studied. Group I: 34 (49.3%) children had previous or current use of systemic corticotherapy (22 girls; 12 boys; mean age: 11.3 years; mean disease duration: 5.9 years; mean corticotherapy duration: 2.9 years; mean cumulative dose of previous corticosteroids: 5000 mg); Group II: 35 (50.7%) children had no previous use of corticosteroids (27 girls; 8 boys; mean age: 11.7 years; mean disease duration: 5.3 years). The groups were compared statistically. RESULTS: In the group that had received corticotherapy (Group I), osteochondral abnormalities were significantly correlated to long-standing disease (>3.5 years; p<0.001). This correlation was not found in the group that had no previous history of corticotherapy (Group II). No correlations were established between median dose of corticosteroids and magnetic resonance imaging findings. CONCLUSION: It is important to further investigate the long-term intra-articular effects of systemic corticotherapy to ensure that the side effects of the aggressive therapy will not be more harmful for the joints than the symptoms suffered over the natural course of the disease.
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Um tratamento do regime de radiação no interior de florestas em conexão com a inversão de modelos matemáticos para estimar as características da vegetação (densidade de área foliar, LAI, etc.) é apresentado e discutido neste estudo. Medidas de radiação solar (PAR) realizadas no período de janeiro a abril de 1994 na Reserva Florestal Ducke (Manaus, AM) foram utilizadas para testar o algoritmo resultante e a distribuição vertical de área foliar para a vegetação local foi estabelecida.
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OBJETIVO: Avaliar as impressões e as opiniões de médicos de áreas clínicas acerca do uso de drogas entre médicos e, mais especificamente, em ambiente cirúrgico. MÉTODOS: Foram sorteados 100 médicos não-residentes de áreas clínicas, selecionados ao acaso entre os profissionais com vínculo em um hospital público de São Paulo. Destes, 83 concluíram o estudo, respondendo perguntas sobre o uso de drogas entre médicos. RESULTADOS: Declararam conhecer algum colega com problemas relacionados ao uso de substâncias 67,5% dos médicos. Esse índice foi de 41,0% quando a pergunta era acerca de drogas disponíveis em ambiente cirúrgico, visto que 68,6% julgam ser fácil o desvio de psicotrópicos desse local. Além disso, 60,2% acreditam que os médicos são mais suscetíveis ao uso abusivo de psicotrópicos quando comparados à população geral. No entanto, 88,0% do total consideram difícil a procura por ajuda especializada. A porcentagem é de 56,6% dos que não conhecem serviço de atendimento direcionado exclusivamente para esses profissionais, algo que, na opinião de 83,1%, facilitaria a busca por tratamento. Dos participantes, 96,4% declararam não apresentar problemas relacionados ao uso de substâncias, ainda que 16,9% admita já ter feito uso de psicotrópicos sem prescrição. CONCLUSÃO: A freqüência de uso de psicotrópicos sem prescrição foi elevada. No entanto, parcela considerável não considera isso problema. A maioria dos profissionais não conhece serviços de atendimento específico para médicos.
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OBJETIVO: Avaliar, morfologicamente, por tomografia computadorizada espiral, enxertos de pericárdio bovino liso empregados como substitutos aórticos. MÉTODOS: Dez pacientes foram submetidos a exame por tomografia computadorizada espiral para reconstituição da imagem dos enxertos. Os critérios de seleção foram tempo de seguimento superior a 2 anos, enxertos de pericárdio liso não revestido, implantados na aorta ascendente ou descendente. RESULTADOS: Os exames demonstraram bom resultado cirúrgico em todos os casos, persistindo em alguns, a imagem de dissecção aórtica distal à anastomose. Um caso apresentava hematoma entre o enxerto e a parede aórtica, em 5 não foram encontradas alterações estruturais no pericárdio e, nos demais, foi detectada dilatação de grau leve, em relação ao diâmetro descrito do enxerto implantado. Não foram vistos sinais de calcificação ou pseudoaneurismas. CONCLUSÃO: Os enxertos tubulares de pericárdio bovino liso, não revestido, apresentam resultados satisfatórios quando empregados como substitutos aórticos. A médio prazo, não foram detectadas anormalidades estruturais relacionadas ao material empregado, pela tomografia computadorizada espiral, exceto dilatação em alguns casos.
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Paciente feminina, 67 anos, internada por infarto agudo do miocárdio de parede lateral, com edema agudo de pulmão e evolução para choque cardiogênico nas primeiras horas. Ecocardiograma transesofágico e ressonância nuclear magnética confirmaram o diagnóstico de pseudoaneurisma de ventrículo esquerdo. A paciente foi submetida a tratamento cirúrgico com sucesso.
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OBJECTIVE: To assess the cardiovascular features of Ullrich-Turner's syndrome using echocardiography and magnetic resonance imaging, and to correlate them with the phenotype and karyotype of the patients. The diagnostic concordance between the 2 methods was also assessed. METHODS: Fifteen patients with the syndrome were assessed by echocardiography and magnetic resonance imaging (cardiac chambers, valves, and aorta). Their ages ranged from 10 to 28 (mean of 16.7) years. The karyotype was analyzed in 11 or 25 metaphases of peripheral blood lymphocytes, or both. RESULTS: The most common phenotypic changes were short stature and spontaneous absence of puberal development (100%); 1 patient had a cardiac murmur. The karyotypes detected were as follows: 45,X (n=7), mosaics (n=5), and deletions (n=3). No echocardiographic changes were observed. In regard to magnetic resonance imaging, coarctation and dilation of the aorta were found in 1 patient, and isolated dilation of the aorta was found in 4 patients. CONCLUSION: The frequencies of coarctation and dilation of the aorta detected on magnetic resonance imaging were similar to those reported in the literature (5.5% to 20%, and 6.3% to 29%, respectively). This confirmed the adjuvant role of magnetic resonance imaging to Doppler echocardiography for diagnosing cardiovascular alterations in patients with Ullrich-Turner's syndrome.
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OBJECTIVE: Doppler tissue imaging (DTI) enables the study of the velocity of contraction and relaxation of myocardial segments. We established standards for the peak velocity of the different myocardial segments of the left ventricle in systole and diastole, and correlated them with the electrocardiogram. METHODS: We studied 35 healthy individuals (27 were male) with ages ranging from 12 to 59 years (32.9 ± 10.6). Systolic and diastolic peak velocities were assessed by Doppler tissue imaging in 12 segments of the left ventricle, establishing their mean values and the temporal correlation with the cardiac cycle. RESULTS: The means (and standard deviation) of the peak velocities in the basal, medial, and apical regions (of the septal, anterior, lateral, and posterior left ventricle walls) were respectively, in cm/s, 7.35(1.64), 5.26(1.88), and 3.33(1.58) in systole and 10.56(2.34), 7.92(2.37), and 3.98(1.64) in diastole. The mean time in which systolic peak velocity was recorded was 131.59ms (±19.12ms), and diastolic was 459.18ms (±18.13ms) based on the peak of the R wave of the electrocardiogram. CONCLUSION: In healthy individuals, maximum left ventricle segment velocities decreased from the bases to the ventricular apex, with certain proportionality between contraction and relaxation (P<0.05). The use of Doppler tissue imaging may be very helpful in detecting early alterations in ventricular contraction and relaxation.
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OBJECTIVE: To assess the usefulness of Doppler tissue imaging (DTI) for evaluating the systolic function of chagasic patients with and without electrocardiographic abnormalities, in comparision with echocardiographic study. METHODS: We studied 77 patients divided into 3 groups as follows: group 1 - control; group 2 - chagasic patients with normal electrocardiographic findings; and group 3 - chagasic patients with abnormal electrocardiographic findings. The following parameters were assessed: left ventricular dimensions and ejection fraction, left atrial dimensions and diastolic function on echocardiography. Systolic velocity and regional isovolumic contraction time (IVCTr) of the septal, anterior, lateral, posterior and inferior left ventricular walls were assessed on DTI. RESULTS: Left ventricular cavitary dimensions, ejection fraction and DTI systolic wave showed significant differences between groups 1 and 3 and between groups 2 and 3, which were not found between groups 1 and 2. IVCTr allowed a statistically significant discrimination among the 3 groups. CONCLUSION: DTI allowed discrimination among the different groups assessed, being superior to echocardiography in identifying early abnormalities of contractility, and, therefore, potentially useful for detecting incipient myocardial alterations in chagasic patients with normal electrocardiographic findings.
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OBJETIVO: Descrever a distribuição dos escores de cálcio coronariano numa população de homens brasileiros brancos assintomáticos submetidos à avaliação pela tomografia ultra-rápida. MÉTODOS: Foram avaliados 2.253 homens de 22-88 anos, submetidos a exame tomográfico num aparelho ImatronR C150 para detecção do cálcio coronariano. Os dados foram separados em 7 faixas etárias: < 40 anos, 40-44 anos, 45-49 anos, 50-54 anos, 55-59 anos, 60-64 anos e >65 anos. RESULTADOS: A média e o desvio padrão da idade foram de 50,0 ± 9,7 anos. Em 48,8% dos casos ocorreu incidência de escore de cálcio coronário > zero, que apresentou distribuição não Gaussiana e mostrou grande variação para a mesma faixa etária. Houve correlação direta entre a idade e o escores de cálcio coronariano (r=0,4, p<0,01). Exceto na comparação entre os indivíduos nas faixas etárias 60-64 anos e, abaixo 55-60 anos e acima de 65 anos, quanto maior a faixa etária maiores as medianas dos escores de cálcio coronariano (p<0,0001). Os escores de cálcio coronariano estão relatados de acordo com os percentis 25,50,75 e 90 para as faixas etárias. CONCLUSÃO: Este estudo, primeiro a relatar a distribuição dos escores de cálcio coronariano em uma amostra de homens brasileiros brancos, pode ser útil para estratificação do risco de eventos coronarianos.