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Ana Babic

Publications and source records attributed to Ana Babic.

2 recordsLinked to original sources
arXiv2018

Fully-Automated Analysis of Body Composition from CT in Cancer Patients Using Convolutional Neural Networks

The amounts of muscle and fat in a person's body, known as body composition, are correlated with cancer risks, cancer survival, and cardiovascular risk. The current gold standard for measuring body composition requires time-consuming manual segmentation of CT images by an expert reader. In this work, we describe a two-step process to fully automate the analysis of CT body composition using a DenseNet to select the CT slice and U-Net to perform segmentation. We train and test our methods on independent cohorts. Our results show Dice scores (0.95-0.98) and correlation coefficients (R=0.99) that are favorable compared to human readers. These results suggest that fully automated body composition analysis is feasible, which could enable both clinical use and large-scale population studies.

cs.CV↗
arXiv2011

Dark matter halos around isolated ellipticals

We investigate the distribution of the luminous and the dark matter components in the isolated ellipticals NGC 7052 and NGC 7785, embedded in an emitting hot gas halo, by means of relevant X-ray and photometric data. In order to calculate the dark matter distribution in these rare objects, we performed an improved X-ray analysis of the XMM-Newton data of NGC 7785, and we used former results based on Chandra data of NGC 7052. For each object we also derived the stellar spheroid length scale from the surface photometry and the spheroid stellar mass from an analysis of the galaxy spectral energy distribution. We find that a dark matter component is present in these objects. It is subdominant and mixed with the luminous matter inside the optical region half-light radius wide, while it dominates the gravitational potential at outer radii. On the whole, the dark halo structure is very similar to that found around spirals of comparable luminosity and it is well reproduced by a Burkert halo, while a Sersic spheroid accounts well for the baryonic component.

astro-ph.CO↗