5,278 research outputs found

    Deep Learning using K-space Based Data Augmentation for Automated Cardiac MR Motion Artefact Detection

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    Quality assessment of medical images is essential for complete automation of image processing pipelines. For large population studies such as the UK Biobank, artefacts such as those caused by heart motion are problematic and manual identification is tedious and time-consuming. Therefore, there is an urgent need for automatic image quality assessment techniques. In this paper, we propose a method to automatically detect the presence of motion-related artefacts in cardiac magnetic resonance (CMR) images. As this is a highly imbalanced classification problem (due to the high number of good quality images compared to the low number of images with motion artefacts), we propose a novel k-space based training data augmentation approach in order to address this problem. Our method is based on 3D spatio-temporal Convolutional Neural Networks, and is able to detect 2D+time short axis images with motion artefacts in less than 1ms. We test our algorithm on a subset of the UK Biobank dataset consisting of 3465 CMR images and achieve not only high accuracy in detection of motion artefacts, but also high precision and recall. We compare our approach to a range of state-of-the-art quality assessment methods.Comment: Accepted for MICCAI2018 Conferenc

    New vascular classification of port-wine stains: improving prediction of Sturge-Weber risk

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    Background Facial port-wine stains (PWSs) are usually isolated findings; however, when associated with cerebral and ocular vascular malformations they form part of the classical triad of Sturge–Weber syndrome (SWS). Objectives To evaluate the associations between the phenotype of facial PWS and the diagnosis of SWS in a cohort with a high rate of SWS. Methods Records were reviewed of all 192 children with a facial PWS seen in 2011–13. Adverse outcome measures were clinical (seizures, abnormal neurodevelopment, glaucoma) and radiological [abnormal magnetic resonance imaging (MRI)], modelled by multivariate logistic regression. Results The best predictor of adverse outcomes was a PWS involving any part of the forehead, delineated at its inferior border by a line joining the outer canthus of the eye to the top of the ear, and including the upper eyelid. This involves all three divisions of the trigeminal nerve, but corresponds well to the embryonic vascular development of the face. Bilateral distribution was not an independently significant phenotypic feature. Abnormal MRI was a better predictor of all clinical adverse outcome measures than PWS distribution; however, for practical reasons guidelines based on clinical phenotype are proposed. Conclusions Facial PWS distribution appears to follow the embryonic vasculature of the face, rather than the trigeminal nerve. We propose that children with a PWS on any part of the ‘forehead’ should have an urgent ophthalmology review and a brain MRI. A prospective study has been established to test the validity of these guidelines

    Vigorous star formation hidden by dust in a galaxy at z=1.4z=1.4

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    Near-infrared surveys have revealed a substantial population of enigmatic faint galaxies with extremely red optical-to-near-infrared colours and with a sky surface density comparable to that of faint quasars. There are two scenarios for these extreme colours: (i) these distant galaxies have formed virtually all their stars at very high redshifts and, due to the absence of recently formed stars, the colours are extremely red and (ii) these distant galaxies contain large amounts of dust, severely reddening the rest-frame UV--optical spectrum. HR10 (z=1.44z = 1.44) is considered the archetype of the extremely red galaxies. Here we report the detection of the continuum emission from HR10 at 850μ\mum and at 1250μ\mum, demonstrating that HR10 is a very dusty galaxy undergoing a major episode of star formation. Our result provides a clear example of a high-redshift galaxy where the star formation rate inferred from the ultraviolet luminosity would be underestimated by a factor up to 1000, and shows that great caution should be used to infer the global star formation history of the Universe from optical observations only.Comment: 12 pages, 1 figure, Nature, in press (30 April 1998

    Personal and social norms for food portion sizes in lean and obese adults.

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    BACKGROUND: Portion size is an important component of dietary advice for weight control, but little is known about what portion sizes people consider 'normal'. This study determined the effect of body mass index (BMI), gender, dietary restraint and liking of the food on personal and social portion size norms for a range of foods and the degree of certainty over the norms. METHODS: Thirty lean (BMI 20-25 kg m(-)(2)) and 30 obese (BMI 30-35 kg m(-)(2)) men and women (aged 18-60 years) viewed 17 different portion sizes of 12 foods on a computer screen on two occasions a week apart. Participants responded 'more' or 'less' to each photograph reflecting personal portion size preference or perceived portion sizes of others. Personal and social norms for portion sizes of each food were determined using the method of constant stimuli giving a sigmoidal curve of the probability of answering 'less' over a range of portion sizes. The slope of the sigmoid at the norm gave a measure of certainty about the norm. Regression models were used to examine the effect of BMI, gender, dietary restraint and liking of the food on personal norms, social norms, the relationship between norms, and the slopes. RESULTS: Personal norms were significantly larger in the obese (P=0.026), men (P<0.001), those with lower dietary restraint (P<0.001), and those with higher liking for the food (P<0.001). Social norms were larger for women (P=0.012). The slopes at the norms were 30% shallower in the obese and in men (P<0.001). CONCLUSION: Larger personal norms for portion size among the obese, men, those with lower dietary restraint and those with higher liking for a food imply greater consumption, which may undermine weight control. Shallower slopes for norms in the obese and in men may imply less clearly defined habitual portion sizes.This study was supported by a program grant from the UK Medical Research Council (U105960389).This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/ijo.2015.4

    The OPAL bugs count survey: exploring the effects of urbanisation and habitat characteristics using citizen science

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    Citizen science projects can gather datasets with observation counts and spatiotemporal coverage far in excess of what can easily be achieved using only professional scientists. However, there exists a potential trade-off between the number of participants and the quality of data gathered. The Bugs Count citizen science project had thousands of participants because of its few barriers to taking part, allowing participation by anyone in England with access to any area of outdoor space. It was designed to scope for both the effects of variation in local habitat and urbanisation on broad taxonomic groups of invertebrates, and the responses of six target ‘Species Quest’ species (Adalia bipunctata, Ocypus olens, Aglais urticae, Palomena prasina, Limax maximus, and Bombus hypnorum) to urbanisation. Participants were asked to search for invertebrates in three areas: ‘soft ground surfaces’, ‘human-made hard surfaces’, and ‘plants’ for 15 min per search. Participants recorded counts of taxa found and a range of environmental information about the survey area. Data samples were weighted according to identification experience and participant age and analysed using canonical correspondence analysis, and tests of observation homogeneity. Species Quest species showed species-specific relationships with urbanisation, but broad taxonomic groups did not show significant relationships with urbanisation. The latter were instead influenced by habitat type and microhabitat availability. The approach used demonstrates that citizen science projects with few barriers to entry can gather viable datasets for scoping broad trends, providing that the projects are carefully designed and analysed to ensure data quality

    Giant Cell Arteritis and COVID-19: Similarities and Discriminators. A Systematic Literature Review

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    OBJECTIVE: To identify shared and distinct features of giant cell arteritis (GCA) and Coronavirus disease 2019 (COVID-19) to reduce diagnostic error that could cause delays in correct treatment. METHODS: Two systematic literature reviews determined the frequency of clinical features of GCA and COVID-19 in published reports. Frequencies in each disease were summarised using median and range. RESULTS: Headache was common in GCA but was also observed in COVID-19 (66% for GCA, 10% for COVID-19). Jaw claudication or visual loss (43% and 26% in GCA, respectively) were not reported in COVID-19. Both diseases featured fatigue (38% for GCA, 43% for COVID-19) and elevated inflammatory markers (CRP elevated in 100% of GCA, 66% of COVID-19), but platelet count was elevated in 47% of GCA but 4% of COVID-19. Cough and fever were commonly reported in COVID-19 and less frequently in GCA (cough, 63% for COVID-19 versus 12% for GCA; fever, 83% for COVID-19 versus 27% for GCA). Gastrointestinal upset was occasionally reported in COVID-19 (8%), rarely in GCA (4%). Lymphopenia was more common in COVID-19 than GCA (53% in COVID-19, 2% in GCA). Alteration of smell and taste been described in GCA but their frequency is unclear. CONCLUSION: Overlapping features of GCA and COVID-19 include headache, fever, elevated CRP and cough. Jaw claudication, visual loss, platelet count and lymphocyte count may be more discriminatory. Physicians should be aware of the possibility of diagnostic confusion. We have designed a simple checklist to aid evidence-based evaluation of patients with suspected GCA

    Spatial and temporal investigations of reported movements, births and deaths of cattle and pigs in Sweden

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    <p>Abstract</p> <p>Background</p> <p>Livestock movements can affect the spread and control of contagious diseases and new data recording systems enable analysis of these movements. The results can be used for contingency planning, modelling of disease spread and design of disease control programs.</p> <p>Methods</p> <p>Data on the Swedish cattle and pig populations during the period July 2005 until June 2006 were obtained from databases held by the Swedish Board of Agriculture. Movements of cattle and pigs were investigated from geographical and temporal perspectives, births and deaths of cattle were investigated from a temporal perspective and the geographical distribution of holdings was also investigated.</p> <p>Results</p> <p>Most movements of cattle and pigs were to holdings within 100 km, but movements up to 1200 km occurred. Consequently, the majority of movements occurred within the same county or to adjacent counties. Approximately 54% of the cattle holdings and 45% of the pig holdings did not purchase any live animals. Seasonal variations in births and deaths of cattle were identified, with peaks in spring. Cattle movements peaked in spring and autumn. The maximum number of holdings within a 3 km radius of one holding was 45 for cattle and 23 for pigs, with large variations among counties. Missing data and reporting bias (digit preference) were detected in the data.</p> <p>Conclusion</p> <p>The databases are valuable tools in contact tracing. However since movements can be reported up to a week after the event and some data are missing they cannot replace other methods in the acute phase of an outbreak. We identified long distance transports of cattle and pigs, and these findings support an implementation of a total standstill in the country in the case of an outbreak of foot-and-mouth disease. The databases contain valuable information and improvements in data quality would make them even more useful.</p
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