Andrea Rueda

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In magnetic resonance imaging (MRI), accuracy and precision with which brain structures may be quantified are frequently affected by the partial volume (PV) effect. PV is due to the limited spatial resolution of MRI compared to the size of anatomical structures. Accurate classification of mixed voxels and correct estimation of the proportion of each pure(More)
Magnetic resonance (MR) provides a non-invasive way to investigate changes in the brain resulting from aging or neurodegenerative disorders such as Alzheimer's disease (AD). Performing accurate analysis for population studies is challenging because of the interindividual anatomical variability. A large set of tools is found to perform studies of brain(More)
Resolution in Magnetic Resonance (MR) is limited by diverse physical, technological and economical considerations. In conventional medical practice, resolution enhancement is usually performed with bicubic or B-spline interpolations, strongly affecting the accuracy of subsequent processing steps such as segmentation or registration. This paper presents a(More)
Deformable registration of cortical surfaces facilitates longitudinal and intergroup comparisons of cortical structure and function in the study of many neurodegenerative diseases. Non-rigid cortical matching is a challenging task due to the large variability between individuals and the complexity of the cortex. We present a new framework for computing(More)
In magnetic resonance imaging (MRI), accuracy of brain structures quantification may be affected by the partial volume (PV) effect. PV is due to the limited spatial resolution of MRI compared to the size of anatomical structures. When considering the cortex, measurements can be even more difficult as it spans only a few vox-els. In tight sulci areas, where(More)
Neurodegenerative diseases comprise a wide variety of mental symptoms whose evolution is not directly related to the visual analysis made by radiologists, who can hardly quantify systematic differences. Moreover, automatic brain morphometric analyses, that do perform this quantification, contribute very little to the comprehension of the disease, i.e., many(More)
—This paper presents a semi-automatic segmentation method to extract the liver volume from CT scans, based on discrete deformable surfaces with both a priori shape and intensity information. A shape model of the liver, represented as a triangular mesh, is built and is manually located in the region of interest, to be iteratively deformed in function of the(More)
A mis padres Luz Marina y Pablo A mis hermanitas Joha y Jessy A mi esposo Jonathan Y a mis abuelitas, presentes siempre en mi corazón vi Acknowledgments First, I want to express my sincerest gratitude to my advisor Eduardo Romero, who allowed me to make my dreams come true. Thanks for his continuous support, motivation, thoughtful guidance and for his(More)
Diffusion Weighted (DW) imaging have proven to be useful in brain architectural analyses and in research about the brain tract organization and neuronal connectivity. However, the clinical use of DW images is currently limited by a series of acquisition artifacts, such as the partial volume effect (PVE), that affect the spatial resolution, and therefore,(More)