9 research outputs found

    Volumetria de estruturas cerebrais profundas com imagem RM

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    A Ressonância Magnética é uma técnica de diagnóstico por imagem frequentemente presente na prática clínica e em constante desenvolvimento. É um método moderno e sofisticado de aquisição de imagem e sinal, com elevada qualidade de imagem, relevante para a volumetria cerebral. A volumetria associada a RM facilita a comparação de dados volumétricos por possibilitar a obtenção de dados mais concretos a nível dos volumes das estruturas cerebrais. Atualmente, o interesse no desenvolvimento de metodologias para a análise de estruturas e medição volumétrica tem vindo a aumentar, sendo que, é desejável que seja um método mais automático, rápido e eficaz e que realize a segmentação de imagem com pouca intervenção do operador. Este estudo experimental tem como objetivo a comparação do volume das estruturas subcorticais entre 2 softwares diferentes a fim de testar a robustez de ambos. Os softwares utilizados, o FreeSurfer e o VolBrain, implementam estratégias de segmentação (semi-)automáticas, seguindo paradigmas algorítmicos diferentes. Ambos os softwares são de distribuição livre e utilizados para estudos de anatomia cerebral, incluindo a segmentação de anatomia cortical e subcortical, fornecendo os respetivos volumes. Inicialmente fez-se um estudo sobre os conceitos de aquisição de imagem cerebral por RM e sobre as estratégias de segmentação deformáveis existentes. A segmentação por modelos deformáveis revelou-se produtiva com resultados prometedores, devido ao facto de ser um método flexível e capaz de segmentar casos mais complexos. Antes de realizar a segmentação da nossa base de dados, efetuou-se IV uma análise sobre os softwares utilizados, as estratégias de segmentação e as propriedades de ambos, onde foi possível observar o modus operandi de cada um, assim como as diferenças entre estes. De seguida realizou-se o processamento das imagens da amostra, composta por 35 casos com diferentes estados de saúde (saudável, presença de tumor ou quisto, epilepsia, autismo), de ambos os sexos e com idades entre os 5 e os 50 anos. No fim da segmentação, ambos forneceram dados volumétricos das estruturas subcorticais, que foram devidamente tabelados a fim de serem analisados e comparados. Para uma melhor visualização comparativa da diferença dos volumes obtidos realizou-se uma rede no MeVisLab que permitiu a sobreposição de ambos os resultados. Os resultados demonstram que o FreeSurfer fornece valores, no geral, significativamente superiores aos do VolBrain, em alguns casos mais relevantes que outros. Tais diferenças são possíveis devido a questões algorítmicas e de pipeline. O VolBrain foi considerado mais fiável a nível de resultados que o FreeSurfer, pois este último tem tendência a superestimar as estruturas subcorticais.Magnetic resonance imaging (MRI) is a diagnostic imaging technique frequently present in the clinical practice and in constant development. It is a modern and sophisticated method of image and signal acquisition, with high image quality, relevant to cerebral volumetry. Volumetry associated with MRI facilitates the comparison of volumetric data allowing to obtain more solid data on the volumes of cerebral structures. Currently, the interest in the development of methodologies for the analyses of structures and volumetric measurement has been increasing, so it is desirable that it becomes a more automated, fast and efficient method and able to perform image segmentation with reduced operator intervention. This experimental study aims to compare the volume of subcortical structures between two different softwares to test the robustness of both. The softwares used, FreeSurfer and VolBrain, implements (semi) automatic segmentation strategies, following different algorithmic paradigms. Both softwares are freely available and are used for cerebral anatomy studies, including the segmentation of cortical and subcortical anatomy, providing the respective volumes. Initially, a study was made focusing on the concepts of MR imaging and on the existing deformable segmentation strategies. The segmentation by deformable models proved to be productive with promising results, due to the fact that it is a flexible method capable of segmenting more complex cases. Before segmenting our data, we analyzed the characteristics of the softwares used, the segmentation strategies and the properties of both, being possible to observe the modus operandi of each one, as well as the differences between them. Next, the images of the sample, composed of VI 35 cases with different health states (healthy, presence of tumor or cyst, epilepsy, autism), of both genders and aged between 5 and 50 years, were processed. At the end of segmentation, both provided volumetric data from subcortical structures, which were tabulated for analysis and comparisons. For a better comparative visualization of the difference of the obtained volumes, a network in MeVisLab was performed to inspect the overlap of both results. The results showed that FreeSurfer provides values that are generally significantly higher than those of VolBrain, in some cases more relevant than others. Such differences are possible due to algorithmic and pipeline issues. VolBrain was considered more reliable in terms of results than FreeSurfer, since the latter tends to overestimate the subcortical structures.Mestrado em Tecnologias da Imagem Médic

    Maternal outcomes and risk factors for COVID-19 severity among pregnant women.

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    Pregnant women may be at higher risk of severe complications associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which may lead to obstetrical complications. We performed a case control study comparing pregnant women with severe coronavirus disease 19 (cases) to pregnant women with a milder form (controls) enrolled in the COVI-Preg international registry cohort between March 24 and July 26, 2020. Risk factors for severity, obstetrical and immediate neonatal outcomes were assessed. A total of 926 pregnant women with a positive test for SARS-CoV-2 were included, among which 92 (9.9%) presented with severe COVID-19 disease. Risk factors for severe maternal outcomes were pulmonary comorbidities [aOR 4.3, 95% CI 1.9-9.5], hypertensive disorders [aOR 2.7, 95% CI 1.0-7.0] and diabetes [aOR2.2, 95% CI 1.1-4.5]. Pregnant women with severe maternal outcomes were at higher risk of caesarean section [70.7% (n = 53/75)], preterm delivery [62.7% (n = 32/51)] and newborns requiring admission to the neonatal intensive care unit [41.3% (n = 31/75)]. In this study, several risk factors for developing severe complications of SARS-CoV-2 infection among pregnant women were identified including pulmonary comorbidities, hypertensive disorders and diabetes. Obstetrical and neonatal outcomes appear to be influenced by the severity of maternal disease

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study (Intensive Care Medicine, (2021), 47, 2, (160-169), 10.1007/s00134-020-06234-9)

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    The original version of this article unfortunately contained a mistake. The members of the ESICM Trials Group Collaborators were not shown in the article but only in the ESM. The full list of collaborators is shown below. The original article has been corrected
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