Brain MRI study for glioma segmentation using convolutional neural networks and original post-processing techniques with low computational demand

Gliomas are brain tumors composed of different highly heterogeneous histological subregions. Image analysis techniques to identify relevant tumor substructures have high potential for improving patient diagnosis, treatment and prognosis. However, due to the high heterogeneity of gliomas, the segmentation task is currently a major challenge in the field of medical image analysis. In the present work, the database of the Brain Tumor Segmentation (BraTS) Challenge 2018, composed of multimodal MRI scans of gliomas, was studied. A segmentation methodology based on the design and application of convolutional neural networks (CNNs) combined with original post-processing techniques with low computational demand was proposed. The post-processing techniques were the main responsible for the results obtained in the segmentations. The segmented regions were the whole tumor, the tumor core, and the enhancing tumor core, obtaining averaged Dice coefficients equal to 0.8934, 0.8376, and 0.8113, respectively. These results reached the state of the art in glioma segmentation determined by the winners of the challenge.Comment: 34 pages, 12 tables, 23 figure

Characterizing a Mini Gamma Detector

There are several types of gamma radiation detectors, which have different characteristics depending on its use. We designed and instrumented a gamma detector for low energies of a small and portable size to obtain spectrum from radioactive sources and from that analyze each spectrum. This instrument basically consists of a scintillator crystal coupled to a SiPM this in turn coupled to a PCB card designed with capacitors and resistors for a better signal, a voltage source of 29 volts. For signal acquisition the system must be connected to an oscilloscope this in turn is controlled by a script developed in Python. For the calibration radioactive isotopes with the same dimensions were used, caesium-137 (Cs-137), cobalto-60 (Co-60), sodium-22 (Na-22) and manganese-54 (Mn-54) as gamma ray emission

Building integration of photovoltaic solar systems in the ZAE office building in Germany

Currently, one of the major concerns worldwide is the access to safe, clean and sustainable energy. People’s current life-style and our life on this planet are subject to energy availability. Therefore, latest research projects have focused on developing ways of obtaining clean, safe and renewable energy. Solar photovoltaic energy (PV) is one of those energy sources, where electricity is directly obtained from solar radiation. This paper examines a case study showing the integration of PV modules into an office and lab building located in Erlangen, Germany. Polysun Simulation Software v.5.3 was used for simulating different types, size and location of PV modules in the building selected as case study (Vela Solaris, 2012). Results demonstrate the multiple possibilities for PV integration into buildings, and the advantages and disadvantages of every option regarding electricity production, orientation, modules dimension, aesthetics and CO2 savings. Moreover, the benefits offered to designers and clients when using specialised software during design decision stages are discussed.El acceso a energía de manera segura y constante es actualmente una de las grandes preocupaciones mundiales. La continuación de la vida humana en el planeta y de los estilos de vida actuales están sujetos a la disponibilidad energética. Desde hace varias décadas numerosas investigaciones se han concentrado en buscar fuentes de energía limpias, seguras y renovables. Una de esas fuentes es la solar fotovoltaica, a través de la cual se puede obtener electricidad a partir de la radiación solar. Aquí se presenta un caso de estudio de integración, dimensionamiento y ubicación de módulos fotovoltaicos en un edificio de oficinas y laboratorios ubicado en Erlangen, Alemania. El trabajo se realizó a través de un levantamiento arquitectónico del sitio, un modelo en 3D del edificio, un estudio de sombras y simulaciones de sistemas fotovoltaicos utilizando el programa Polysun Simulation Software v.5.3 (Vela Solaris, 2012). Los resultados obtenidos demuestran las múltiples posibilidades que existen para integrar módulos fotovoltaicos en edificios, así como las ventajas y desventajas de cada opción en términos de producción de energía, orientación, dimensiones de los paneles, estética y de ahorro de CO2. Además se demuestran las ventajas que ofrece la utilización de un software especializado para tomar decisiones de diseño con mayor certeza

Automatic quantification of abdominal subcutaneous and visceral adipose tissue in children, through MRI study, using total intensity maps and Convolutional Neural Networks

Childhood overweight and obesity is one of the main health problems in the world since it is related to the early appearance of different diseases, in addition to being a risk factor for later developing obesity in adulthood with its health and economic consequences. Visceral abdominal tissue (VAT) is strongly related to the development of metabolic and cardiovascular diseases compared to abdominal subcutaneous adipose tissue (ASAT). Therefore, precise and automatic VAT and ASAT quantification methods would allow better diagnosis, monitoring and prevention of diseases caused by obesity at any stage of life. Currently, magnetic resonance imaging is the standard for fat quantification, with Dixon sequences being the most useful. Different semiautomatic and automatic ASAT and VAT quantification methodologies have been proposed. In particular, the semi-automated quantification methodology used commercially through the cloud-based service AMRA R Researcher stands out due to its extensive validation in different studies. In the present work, a database made up of Dixon MRI sequences, obtained from children between 7 and 9 years of age, was studied. Applying a preprocessing to obtain what we call total intensity maps, a convolutional neural network (CNN) was proposed for the automatic quantification of ASAT and VAT. The quantifications obtained from the proposed methodology were compared with quantifications previously made through AMRA R Researcher. For the comparison, correlation analysis, Bland-Altman graphs and non-parametric statistical tests were used. The results indicated a high correlation and similar precisions between the quantifications of this work and those of AMRA R Researcher. The final objective is that the proposed methodology can serve as an accessible and free tool for the diagnosis, monitoring and prevention of diseases related to childhood obesity.Comment: 14 pages, 9 figures, 3 table

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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

An EPI and fMRI assessment of the effect of viscosity on satiety

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A multi-methodological MR resting state network analysis to assess the changes in brain physiology of children with ADHD.

The purpose of this work was to highlight the neurological differences between the MR resting state networks of a group of children with ADHD (pre-treatment) and an age-matched healthy group. Results were obtained using different image analysis techniques. A sample of n = 46 children with ages between 6 and 12 years were included in this study (23 per cohort). Resting state image analysis was performed using ReHo, ALFF and ICA techniques. ReHo and ICA represent connectivity analyses calculated with different mathematical approaches. ALFF represents an indirect measurement of brain activity. The ReHo and ICA analyses suggested differences between the two groups, while the ALFF analysis did not. The ReHo and ALFF analyses presented differences with respect to the results previously reported in the literature. ICA analysis showed that the same resting state networks that appear in healthy volunteers of adult age were obtained for both groups. In contrast, these networks were not identical when comparing the healthy and ADHD groups. These differences affected areas for all the networks except the Right Memory Function network. All techniques employed in this study were used to monitor different cerebral regions which participate in the phenomenological characterization of ADHD patients when compared to healthy controls. Results from our three analyses indicated that the cerebellum and mid-frontal lobe bilaterally for ReHo, the executive function regions in ICA, and the precuneus, cuneus and the clacarine fissure for ALFF, were the "hubs" in which the main inter-group differences were found. These results do not just help to explain the physiology underlying the disorder but open the door to future uses of these methodologies to monitor and evaluate patients with ADHD