5,765 research outputs found

    Prevalence of Incidental Pancreatic Cysts on 3 Tesla Magnetic Resonance

    Get PDF
    ObjectivesTo ascertain the prevalence of pancreatic cysts detected incidentally on 3-Tesla magnetic resonance imaging (MRI) of the abdomen and correlate this prevalence with patient age and gender; assess the number, location, and size of these lesions, as well as features suspicious for malignancy; and determine the prevalence of incidentally detected dilatation of the main pancreatic duct (MPD).MethodsRetrospective analysis of 2,678 reports of patients who underwent abdominal MRI between January 2012 and June 2013. Patients with a known history of pancreatic conditions or surgery were excluded, and the remaining 2,583 reports were examined for the presence of pancreatic cysts, which was then correlated with patient age and gender. We also assessed whether cysts were solitary or multiple, as well as their location within the pancreatic parenchyma, size, and features suspicious for malignancy. Finally, we calculated the prevalence of incidental MPD dilatation, defined as MPD diameter >= 2.5 mm.ResultsPancreatic cysts were detected incidentally in 9.3% of patients (239/2,583). the prevalence of pancreatic cysts increased significantly with age (p= 5 mm in size; 12.1% were suspicious for malignancy. An estimated 2.7% of subjects had a dilated MPD.Universidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Imaging Diag, São Paulo, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Imaging Diag, São Paulo, SP, BrazilWeb of Scienc

    Service composition in stochastic settings

    Get PDF
    With the growth of the Internet-of-Things and online Web services, more services with more capabilities are available to us. The ability to generate new, more useful services from existing ones has been the focus of much research for over a decade. The goal is, given a specification of the behavior of the target service, to build a controller, known as an orchestrator, that uses existing services to satisfy the requirements of the target service. The model of services and requirements used in most work is that of a finite state machine. This implies that the specification can either be satisfied or not, with no middle ground. This is a major drawback, since often an exact solution cannot be obtained. In this paper we study a simple stochastic model for service composition: we annotate the tar- get service with probabilities describing the likelihood of requesting each action in a state, and rewards for being able to execute actions. We show how to solve the resulting problem by solving a certain Markov Decision Process (MDP) derived from the service and requirement specifications. The solution to this MDP induces an orchestrator that coincides with the exact solution if a composition exists. Otherwise it provides an approximate solution that maximizes the expected sum of values of user requests that can be serviced. The model studied although simple shades light on composition in stochastic settings and indeed we discuss several possible extensions

    Current role of imaging methods in the diagnosis of cystic solid pancreas neoplasms: part I

    Get PDF
    Os autores fazem uma revisão considerando o valor da colangiopancreatografia endoscópica retrógrada, da ultrassonografia, da tomografia computadorizada, da ressonância magnética e da ecoendoscopia para o diagnóstico das neoplasias císticas e sólidas do pâncreas, demonstrando que cada um deles tem grande importância para aumentar, de forma inconteste, a acurácia diagnóstica das doenças do sistema biliopancreático. determinando qual o melhor método para cada um dos diversos tumores.The authors address the value of endoscopic retrograde cholangiopancreatography, ultrasonography, computed tomography, magnetic resonance imaging and endoscopic ultrasound for the diagnosis of cystic and solid neoplasms of the pancreas, demonstrating that each of them is of great importance to undoubtedly increase the diagnostic accuracy of the biliopancreatic system diseases. The best method for each of several tumors is then determined

    Study on the frequency of caries and associated factors in type 1 diabetes mellitus

    Get PDF
    Subjects with diabetes mellitus (DM) are more prone to certain disturbances of oral cavity but there are controversies concerning caries. This cross-sectional study investigated the frequency of caries and associated factors, in a sample of population with or without type 1 DM, including non-diabetic (53 women, 31 men) and 30 diabetic subjects (19 women, 11 men) aged 17-28 years. Diagnosis of dental caries was based on the DMF-T index (D= decay; M= miss; F= fill; T= teeth); in addition, a plaque control record (PCR) was obtained. A preponderance of female sex was found within the groups studied but such proportions did not differ when comparing diabetic and non-diabetic groups. Mean ages were 21.0 ± 2.2 and 19.5 ± 1.8 years, respectively for subjects without and with DM (p< 0.05). Education level was higher in the non-diabetic group as well as the DMF-T index (10.5 ± 5.8 vs. 6.7 ± 5.7, p< 0.01). Linear regression analysis (n= 114) showed significant associations of DMF-T with age, sucrose intake, daily frequency of tooth brushing, of dental floss use, PCR and of visits to the dentist. By ANOVA model with age as a covariate the non-diabetic condition (p= 0.047), sucrose index and PCR (r²= 0.820) were independently associated with the DMF-T. In the diabetic-specific model, with only the diabetic subjects included and sucrose index as a covariate, DM duration, fundus abnormality and PCR were significantly associated with the presence of caries (r²= 0.816). The sample of type 1 diabetic subjects suggest that they are less prone to caries than non-diabetics, despite having a higher frequency of meals, less tooth brushing and dental floss use. We speculate that DM duration may contribute to the occurrence of caries and restricted sucrose consumption to lower frequency of caries in diabetic subjects.Indivíduos com diabetes mellitus (DM) são mais susceptíveis a doenças da cavidade bucal, havendo controvérsias quanto à cárie. Este estudo transversal investigou a freqüência de cárie e fatores associados em amostra portadora ou não de DM tipo 1, incluindo-se 84 jovens não-diabéticos (53F / 31M) e 30 diabéticos (19F / 11M) entre 17-28 anos. O diagnóstico de cárie baseou-se no índice de CPO-D (dentes C= cariados; P= perdidos; O= obturados); além deste, foi obtido registro de controle de placa (RCP). Nos grupos estudados houve predomínio do sexo feminino, embora estas proporções não tenham diferido entre os grupos diabético e não-diabético. As médias de idade foram de 21,0 ± 2,2 e 19,5 ± 1,8 anos, respectivamente para indivíduos sem e com DM (p< 0,05). A escolaridade foi mais elevada no grupo não-diabético, assim como o índice de CPO-D (10,5 ± 5,8 vs. 6,7 ± 5,7; p< 0,01). A análise de regressão simples (n= 114) mostrou associações significantes da CPO-D com idade, consumo de sacarose, número de escovações diárias, uso do fio dental, RCP e de visitas ao dentista. Em modelo de ANOVA, tendo a idade como co-variável, associaram-se significantemente à CPO-D a condição não-diabética, índice de sacarose e RCP (r²= 0,820). No modelo que incluiu apenas o grupo com DM, tendo o índice de sacarose como co-variável, o tempo de DM, anormalidade da fundoscopia e RCP associaram-se significantemente à cárie (r²= 0,816). A amostra de indivíduos diabéticos sugere que estes apresentam menos cáries que os não-diabéticos, apesar de realizarem maior número de refeições e menor uso de escovação e fio dental. Especula-se que a duração do DM possa contribuir para ocorrência de cárie e o consumo restrito de sacarose para menor freqüência de cárie em portadores de DM.Universidade Federal de São Paulo (UNIFESP) Departamento de Medicina PreventivaUSPUNIFESP, Depto. de Medicina PreventivaSciEL

    Magnetic resonance spectroscopy imaging in the diagnosis of prostate cancer: initial experience

    Get PDF
    OBJECTIVE: To report an experiment involving the introduction of a protocol utilizing commercially available three-dimensional 1H magnetic resonance spectroscopy imaging (3D 1H MRSI) method in patients diagnosed with prostatic tumors under suspicion of neoplasm. MATERIALS AND METHODS: Forty-one patients in the age range between 51 and 80 years (mean, 67 years) were prospectively evaluated. The patients were divided into two groups: patients with one or more biopsies negative for cancer and high specific-prostatic antigen levels (group A), and patients with cancer confirmed by biopsy (group B). The determination of the target-area (group A) or the known cancer extent (group B) was based on magnetic resonance imaging and MRSI studies. RESULTS: The specificity of MRSI in the diagnosis of prostate cancer was lower than the specificity reported in the literature (about 47%). On the other hand, for tumor staging, it corresponded to the specificity reported in the literature. CONCLUSION: The introduction and standardization of 3D 1H MRSI has allowed the obtention of a presumable diagnosis of prostate cancer, by a combined analysis of magnetic resonance imaging and metabolic data from 3D 1H MRSI.OBJETIVO: Demonstrar a experiência na implantação de um protocolo de espectroscopia por ressonância magnética do 1H tridimensional (3D 1H MRSI), disponível comercialmente, aplicando-o em pacientes com suspeita de neoplasia prostática e com diagnóstico estabelecido de tumor prostático. MATERIAIS E MÉTODOS: Estudo realizado de forma prospectiva, em 41 pacientes com idades entre 51 e 80 anos (média de 67 anos). Dois grupos foram formados: pacientes com uma ou mais biópsias negativas para câncer e antígeno prostático específico elevado (grupo A) e pacientes com câncer confirmado por biópsia (grupo B). Procurou-se, a partir dos resultados da ressonância magnética e espectroscopia por ressonância magnética, determinar a área-alvo (grupo A) ou a extensão do câncer conhecido (grupo B). RESULTADOS: No diagnóstico de câncer de próstata a espectroscopia por ressonância magnética apresentou especificidade abaixo da descrita pela literatura, cerca de 47%. Já para o estadiamento do tumor diagnosticado, houve correspondência com a literatura. CONCLUSÃO: A implantação e padronização da espectroscopia por ressonância magnética permitiram a obtenção de informações importantes para o diagnóstico presuntivo da existência de câncer de próstata, combinando as imagens por ressonância magnética com os dados metabólicos da espectroscopia por ressonância magnética.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Diagnóstico por ImagemUniversidade Federal do AmazonasUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Hospital São PauloUNIFESP, EPM, Depto. de Diagnóstico por ImagemUNIFESP, EPM, Hospital São PauloSciEL

    Estudo da eficácia e da reprodutibilidade da colangiopancreatografia por ressonância magnética na detecção das complicações biliares pós-transplantes hepáticos

    Get PDF
    PURPOSE: To evaluate the accuracy and reproducibility of magnetic resonance cholangiopancreatography (MRCP) in the detection of biliary complications in liver transplanted patients. METHODS: A study was conducted, with blinded review of 28 MRCP exams of 24 patients submitted to liver transplantation. The images were reviewed by two independent observers, at two different moments, regarding the degree of biliary tree visualization and the presence or absence of biliary complications. The MRCP results were compared, when negative, to at least 3 months of clinical and biochemical follow-up, and when positive, to the findings at surgery or endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: The degree of intrahepatic biliary tree visualization was considered good or excellent in 78.6% and 82.1% of the exams by the two observers and visualization of the donor duct, recipient duct and biliary anastomosis was considered good or excellent in 100% of the exams, by both observers. Six biliary complications were detected (21.4%), all of them anastomotic strictures. Intra and interobserver agreement were substantial or almost perfect (kappa k values of 0.611 to 0.804) for the visualization of the biliary tree and almost perfect (k values of 0.900 to 1.000) for the detection of biliary complications. MRCP achieved 100% sensitivity, 95.45% specificity, 85.7% positive predictive value and 100% negative predictive value for the detection of biliary complications. CONCLUSIONS: MRCP is an accurate examination for the detection of biliary complications after orthotopic liver transplantation and it is a highly reproducible method in the evaluation of the biliary tree of liver transplanted patients.OBJETIVO: Medir a acurácia e reprodutibilidade da colangiopancreatografia por ressonância magnética (CPRM) na avaliação da visibilização de complicações biliares em pacientes submetidos a transplantes hepáticos ortotópicos. MÉTODOS: Realizado estudo retrospectivo de 28 exames de CPRM de 24 pacientes submetidos a transplantes hepáticos. Os exames foram interpretados por dois observadores independentes, em dois momentos distintos, quanto ao grau de visibilização das estruturas estudadas e quanto à presença ou ausência de alterações nas vias biliares. Os resultados da CPRM foram comparados, nos casos de CPRM negativa, à evolução clínico-laboratorial por pelo menos 3 meses e, nos casos de CPRM alterada, aos achados de colangiopancreatografia retrógrada endoscópica (CPRE) e cirurgia, quando indicados. RESULTADOS: A visibilização das vias biliares intra-hepáticas foi considerada boa ou excelente em 78,6% e 82,1% dos exames pelos dois observadores. A visibilização da via biliar extra-hepática do doador e do receptor, bem como da anastomose biliar, foi considerada boa ou excelente em 100% dos casos por ambos os observadores. Foram detectadas seis complicações biliares (21,4% dos casos), todas elas estenoses anastomóticas. A concordância intra e intra-observador foi substancial ou quase perfeita (índices de kappa- k de 0,611 a 0,804) para a visualização das estruturas estudadas e quase perfeita (k de 0,900 a 1,000) para a detecção das complicações biliares. A CPRM apresentou sensibilidade de 100%, especificidade de 95,45%, valor preditivo positivo de 85,7% e valor preditivo negativo de 100% para a detecção de complicações biliares. CONCLUSÕES: A colangiopancreatografia por ressonância magnética (CPRM) é um exame acurado para a detecção de complicações biliares em pacientes submetidos a transplantes hepáticos ortotópicos por CPRM. Este exame configura-se como um método eficiente e altamente reprodutível para detecção de complicações biliares pós-transplantes hepáticos ortotópicos.Universidade Federal de São Paulo (UNIFESP) Department of SurgeryUniversidade Federal de São Paulo (UNIFESP) Department of Image DiagnosticUniversidade Federal de São Paulo (UNIFESP) Department of MedicineUniversidade Federal de São Paulo (UNIFESP) Department of Surgery Division of Liver TransplantationUniversidade Federal de São Paulo (UNIFESP) Department of Surgery Division of Surgical GastroenterologyUNIFESP, Department of SurgeryUNIFESP, Department of Image DiagnosticUNIFESP, Department of MedicineUNIFESP, Department of Surgery Division of Liver TransplantationUNIFESP, Department of Surgery Division of Surgical GastroenterologySciEL

    Fetal brain fissures development a three-dimensional ultrasonography study

    Get PDF
    PURPOSE: to assess the distance of the fetal cerebral fissures from the inner edge of the skull by three-dimensional ultrasonography (3DUS). METHODS: this cross-sectional study included 80 women with normal pregnancies between 21st and 34th weeks. The distances between the Sylvian, parieto-occiptal, hippocampus and calcarine fissures and the internal surface of the fetal skull were measured. For the evaluation of the distance of the first three fissures, an axial three-dimensional scan was obtained (at the level of the lateral ventricles). To obtain the calcarine fissure measurement, a coronal scan was used (at the level of the occipital lobes). First degree regressions were performed to assess the correlation between fissure measurements and gestational age, using the determination coefficient (R²) for adjustment. The 5th, 50th and 95th percentiles were calculated for each fissure measurement. Pearson's correlation coefficient (r) was used to assess the correlation between fissure measurements and the biparietal diameter (BPD) and head circumference (HC). RESULTS: all fissure measurements were linearly correlated with gestational age (Sylvian: R²=0.5; parieto-occiptal: R²= 0.7; hippocampus: R²= 0.3 and calcarine: R²= 0.3). Mean fissure measurement ranged from 7.0 to 14.0 mm, 15.9 to 28.7 mm, 15.4 to 25.4 mm and 15.7 to 24.8 mm for the Sylvian, parieto-occiptal, hippocampus and calcarine fissures, respectively. The Sylvian and parieto-occiptal fissure measurements had the highest correlations with the BPD (r=0.8 and 0.7, respectively) and HC (r=0.7 and 0.8, respectively). CONCLUSION: the distance from the fetal cerebral fissures to the inner edge of the skull measured by 3DUS was positively correlated with gestational age.OBJETIVO: avaliar a distância das fissuras cerebrais fetais à borda interna da calota craniana por meio da ultrassonografia tridimensional (US3D). MÉTODOS: realizou-se um estudo de corte transversal em 80 gestantes normais entre a 21ª e 34ª semanas de gestação. Avaliou-se a distância entre a tábua óssea interna da calota craniana fetal e as fissuras de Sylvius, parieto-occipital, hipocampo e calcarina. Para a obtenção desta distância para as três primeiras fissuras, realizou-se uma varredura tridimensional através do plano axial (nível dos ventrículos laterais). Para a obtenção da distância da fissura calcarina utilizou-se uma varredura coronal (nível dos lobos occiptais). Para avaliar a correlação entre as fissuras e a idade gestacional foram realizadas regressões de primeiro grau, sendo os ajustes calculados pelo coeficiente de determinação (R²). Foram determinados percentis 5, 50 e 95 para cada fissura. Avaliou-se ainda a correlação entre a distância destas fissuras com os diâmetros biparietal (DBP) e circunferência craniana (CC) utilizando o coeficiente de correlação de Pearson (r). RESULTADOS: todas as medidas das fissuras apresentaram correlação linear com a idade gestacional (Sylvius: R²=0,5; parieto-occipital: R²=0,7; hipocampo: R²=0,3 e calcarina: R²=0,3). A média da distância das fissuras variou de 7,0 a 14,0 mm, 15,9 a 28,7 mm, 15,4 a 25,4 mm e 15,7 a 24,8 mm para as fissuras de Sylvius, parieto-occipital, hipocampo e calcarina, respectivamente. As fissuras de Sylvius e parieto-occipital apresentaram as maiores correlações com o DBP (r=0,8 e 0,7, respectivamente) e a CC (r=0,7 e 0,8, respectivamente). CONCLUSÕES: a distância das fissuras cerebrais fetais à borda interna da calota craniana por meio da US3D apresentou correlação positiva com a idade gestacional.Universidade Federal de São Paulo (UNIFESP) Departamento de ObstetríciaUniversidade Federal de São Paulo (UNIFESP) Departamento de Diagnóstico por Imagem Setor de Ressonância MagnéticaUniversidade Federal de São Paulo (UNIFESP) Departamento de Diagnóstico por ImagemUNIFESP, Depto. de ObstetríciaUNIFESP, Depto. de Diagnóstico por Imagem Setor de Ressonância MagnéticaUNIFESP, Depto. de Diagnóstico por ImagemSciEL

    Microwave-Driven Hexagonal-to-Monoclinic Transition in BiPO4: An In-Depth Experimental Investigation and First-Principles Study

    Get PDF
    Present theoretical and experimental work provides an in-depth understanding of the morphological, structural, electronic, and optical properties of hexagonal and monoclinic polymorphs of bismuth phosphate (BiPO4). Herein, we demonstrate how microwave irradiation induces the transformation of a hexagonal phase to a monoclinic phase in a short period of time and, thus, the photocatalytic performance of BiPO4. To complement and rationalize the experimental results, first-principles calculations have been performed within the framework of density functional theory. This was aimed at obtaining the geometric, energetic, and structural parameters as well as vibrational frequencies; further, the electronic properties (band structure diagram and density of states) of the bulk and corresponding surfaces of both the hexagonal and monoclinic phases of BiPO4 were also acquired. A detailed characterization of the low vibrational modes of both the hexagonal and monoclinic polymorphs is key to explaining the irreversible phase transformation from hexagonal to monoclinic. On the basis of the calculated values of the surface energies, a map of the available morphologies of both phases was obtained by using Wulff construction and compared to the observed scanning electron microscopy images. The BiPO4 crystals obtained after 16–32 min of microwave irradiation provided excellent photodegradation of Rhodamine B under visible-light irradiation. This enhancement was found to be related to the surface energy and the types of clusters formed on the exposed surfaces of the morphology. These findings provide details of the hexagonal-to-monoclinic phase transition in BiPO4 during microwave irradiation; further, the results will assist in the design of electronic devices with higher efficiency and reliability
    • …
    corecore