@article {954, title = {Moment-based representation of the diffusion inside the brain from reduced DMRI acquisitions: Generalized AMURA}, journal = {Medical Image Analysis}, volume = {77}, year = {2022}, pages = {102356}, abstract = {

AMURA (Apparent Measures Using Reduced Acquisitions) was originally proposed as a method to infer micro-structural information from single-shell acquisitions in diffusion MRI. It reduces the number of samples needed and the computational complexity of the estimation of diffusion properties of tissues by assuming the diffusion anisotropy is roughly independent on the b-value. This simplification allows the computation of simplified expressions and makes it compatible with standard acquisition protocols commonly used even in clinical practice. The present work proposes an extension of AMURA that allows the calculation of general moments of the diffusion signals that can be applied to describe the diffusion process with higher accuracy. We provide simplified expressions to analytically compute a set of scalar indices as moments of arbitrary orders over either the whole 3-D space, particular directions, or particular planes. The existing metrics previously proposed for AMURA (RTOP, RTPP and RTAP) are now special cases of this generalization. An extensive set of experiments is performed on public data and a clinical clase acquired with a standard type acquisition. The new metrics provide additional information about the diffusion processes inside the brain.

}, keywords = {AMURA, Diffusion anisotropy, Fast acquisition, diffusion MRI, white matter}, issn = {1361-8415}, doi = {https://doi.org/10.1016/j.media.2022.102356}, url = {https://www.sciencedirect.com/science/article/pii/S1361841522000093}, author = {Aja-Fern{\'a}ndez, Santiago and Pieciak, Tomasz and Mart{\'\i}n-Mart{\'\i}n, Carmen and {\'A}lvaro Planchuelo-G{\'o}mez and de Luis-Garc{\'\i}a, Rodrigo and Trist{\'a}n-Vega, Antonio} } @article {947, title = {Magnetic Resonance Simulation in Education: Quantitative Evaluation of an Actual Classroom Experience}, journal = {Sensors}, volume = {21}, year = {2021}, pages = {6011}, abstract = {

Magnetic resonance is an imaging modality that implies a high complexity for radiographers. Despite some simulators having been developed for training purposes, we are not aware of any attempt to quantitatively measure their educational performance. The present study gives an answer to the question: Does an MRI simulator built on specific functional and non-functional requirements help radiographers learn MRI theoretical and practical concepts better than traditional educational method based on lectures? Our study was carried out in a single day by a total of 60 students of a main hospital in Madrid, Spain. The experiment followed a randomized pre-test post-test design with a control group that used a traditional educational method, and an experimental group that used our simulator. Knowledge level was assessed by means of an instrument with evidence of validity in its format and content, while its reliability was analyzed after the experiment. Statistical differences between both groups were measured. Significant statistical differences were found in favor of the participants who used the simulator for both the post-test score and the gain (difference between post-test and pre-test scores). The effect size turned out to be significant as well. In this work we evaluated a magnetic resonance simulation paradigm as a tool to help in the training of radiographers. The study shows that a simulator built on specific design requirements is a valuable complement to traditional education procedures, backed up with significant quantitative results.

}, author = {Trece{\~n}o-Fern{\'a}ndez, Daniel and Calabia-del-Campo, Juan and Matute-Teresa, F{\'a}tima and Bote-Lorenzo, Miguel L and G{\'o}mez-S{\'a}nchez, Eduardo and Rodrigo de Luis-Garc{\'\i}a and Alberola-L{\'o}pez, Carlos} } @article {943, title = {Medium-term changes in patients with epilepsy during the COVID-19 pandemic}, journal = {Acta Neurologica Scandinavica}, volume = {144}, year = {2021}, pages = {450-459}, abstract = {

Objectives: The novel coronavirus disease (COVID-19) pandemic has led to social distancing measures and impaired medical care of chronic neurological diseases, including epilepsy, which may have adversely affected well-being and quality of life of patients with epilepsy (PWE). The objective of this study is to evaluate the impact of the COVID-19 pandemic in the levels of anxiety, depression, somnolence, and quality of life using validated scales in PWE in real-life clinical practice.

Materials \& Methods: Self-administered scales of anxiety disorders (GAD-7), depression (NDDI-E), somnolence (Epworth Sleepiness Scale; ESS), and quality of life (QOLIE-31-P) in PWE treated in a Refractory Epilepsy Unit were longitudinally analyzed. Data were collected before the beginning (December 2019-March 2020) and during the COVID-19 pandemic (September 2020-January 2021).

Results: 158 patients (85 from the first round and 73 from the second round) 45.0 +- 17.3 years of age, 43.2\% women, epilepsy duration 23.0 +- 14.9 years, number of antiepileptic drugs 2.1 +- 1.4, completed the survey. Significant longitudinal reduction of QOLIE-31-P (from 58.9 +- 19.7 to 56.2 +- 16.2, p = 0.035) and GAD-7 scores (from 8.8 +- 6.2 to 8.3 +- 5.9, corrected p = .024) was identified. No statistically significant longitudinal changes in the number of seizures (from 0.9 +- 1.9 to 2.5 +- 6.2, p = .125) or NDDI-E scores (from 12.3 +- 4.3 to 13.4 +- 4.4, p = .065) were found. Significant longitudinal increase of ESS (from 4.9 +- 3.7 to 7.4 +- 4.9, p = .001) was found.

Conclusions: During the COVID-19 pandemic, quality of life and anxiety levels were lower in PWE, and sleepiness levels were raised, without seizure change.

}, keywords = {Anxiety, COVID-19, Sleep, epilepsy, pandemic, quality of life}, doi = {https://doi.org/10.1111/ane.13481}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ane.13481}, author = {Gonzalez-Martinez, Alicia and {\'A}lvaro Planchuelo-G{\'o}mez and Vieira Campos, Alba and Mart{\'\i}nez-Dubarbie, Francisco and Vivancos, Jos{\'e} and De Toledo-Heras, Mar{\'\i}a} } @article {907, title = {Multimodal fusion analysis of structural connectivity and gray matter morphology in migraine}, journal = {Human Brain Mapping}, volume = {42}, year = {2021}, pages = {908-921}, abstract = {

No specific migraine biomarkers have been found in single-modality MRI studies. We aimed at establishing biomarkers for episodic and chronic migraine using diverse MRI modalities. We employed canonical correlation analysis and joint independent component analysis to find structural connectivity abnormalities that are related to gray matter morphometric alterations. The number of streamlines (trajectories of estimated fiber-tracts from tractography) was employed as structural connectivity measure, while cortical curvature, thickness, surface area, and volume were used as gray matter parameters. These parameters were compared between 56 chronic and 54 episodic migraine patients, and 50 healthy controls. Cortical curvature alterations were associated with abnormalities in the streamline count in episodic migraine patients compared to controls, with higher curvature values in the frontal and temporal poles being related to a higher streamline count. Lower streamline count was found in migraine compared to controls in connections between cortical regions within each of the four lobes. Higher streamline count was found in migraine in connections between subcortical regions, the insula, and the cingulate and orbitofrontal cortex, and between the insula and the temporal region. The connections between the caudate nucleus and the orbitofrontal cortex presented worse connectivity in chronic compared to episodic migraine. The hippocampus was involved in connections with higher and lower number of streamlines in chronic migraine. Strengthening of structural networks involving pain processing and subcortical regions coexists in migraine with weakening of cortical networks within each lobe. The multimodal analysis offers a new insight about the association between brain structure and connectivity.

}, keywords = {Brain, Magnetic Resonance Imaging, connectome, diffusion magnetic resonance imaging, migraine disorders}, doi = {https://doi.org/10.1002/hbm.25267}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/hbm.25267}, author = {{\'A}lvaro Planchuelo-G{\'o}mez and Garc{\'\i}a-Azor{\'\i}n, David and {\'A}ngel L. Guerrero and Santiago Aja-Fern{\'a}ndez and Rodr{\'\i}guez, Margarita and Rodrigo de Luis-Garc{\'\i}a} } @article {844, title = {Micro-structure diffusion scalar measures from reduced MRI acquisitions}, journal = {PLOS ONE}, volume = {15}, year = {2020}, month = {2020}, pages = {1-25}, abstract = {

In diffusion MRI, the Ensemble Average diffusion Propagator (EAP) provides relevant micro-structural information and meaningful descriptive maps of the white matter previously obscured by traditional techniques like Diffusion Tensor Imaging (DTI). The direct estimation of the EAP, however, requires a dense sampling of the Cartesian q-space involving a huge amount of samples (diffusion gradients) for proper reconstruction. A collection of more efficient techniques have been proposed in the last decade based on parametric representations of the EAP, but they still imply acquiring a large number of diffusion gradients with different b-values (shells). Paradoxically, this has come together with an effort to find scalar measures gathering all the q-space micro-structural information probed in one single index or set of indices. Among them, the return-to-origin (RTOP), return-to-plane (RTPP), and return-to-axis (RTAP) probabilities have rapidly gained popularity. In this work, we propose the so-called {\textquotedblleft}Apparent Measures Using Reduced Acquisitions{\textquotedblright} (AMURA) aimed at computing scalar indices that can mimic the sensitivity of state of the art EAP-based measures to micro-structural changes. AMURA drastically reduces both the number of samples needed and the computational complexity of the estimation of diffusion properties by assuming the diffusion anisotropy is roughly independent from the radial direction. This simplification allows us to compute closed-form expressions from single-shell information, so that AMURA remains compatible with standard acquisition protocols commonly used even in clinical practice. Additionally, the analytical form of AMURA-based measures, as opposed to the iterative, non-linear reconstruction ubiquitous to full EAP techniques, turns the newly introduced apparent RTOP, RTPP, and RTAP both robust and efficient to compute.

}, doi = {10.1371/journal.pone.0229526}, url = {https://doi.org/10.1371/journal.pone.0229526}, author = {Santiago Aja-Fern{\'a}ndez and Rodrigo de Luis-Garc{\'\i}a and Maryam Afzali and Molendowska, Malwina and Tomasz Pieciak and Antonio Trist{\'a}n-Vega} } @article {801, title = {A Machine Hearing System for Robust Cough Detection Based on a High-Level Representation of Band-Specific Audio Features}, journal = {IEEE Transactions on Biomedical Engineering}, volume = {66}, year = {2019}, pages = {2319-2330}, author = {Monge-Alvarez, Jesus and Hoyos-Barcelo, Carlos and San Jose-Revuelta, Luis M and Pablo Casaseca-de-la-Higuera} } @proceedings {810, title = {Motion-Robust and Blood-Suppressed M1-Optimized Diffusion MR Imaging of the Liver}, volume = {116}, year = {2019}, abstract = {

Liver DWI has been shown to enable the detection, characterization and treatment monitoring of focal liver lesions, as well as the assessment of diffuse liver disease (eg: fibrosis and cirrhosis)1,2. However, liver DWI is challenging because of the relatively short T2 of liver tissue and the motion sensitivity of diffusion encoding sequences3,4. Recently, advanced motion-robust DW gradient waveform design techniques5-7 enabled first motion moment-nulled (M1-nulled) and/or second motion moment nulled (M2-nulled) DWI with optimized echo time (TE). However, these motion moment-nulled gradient waveforms also compensate the signal from moving blood, which is nulled in standard liver DWI. Importantly, non-suppressed blood signal can mimic focal liver lesions and may confound the assessment and detection of true focal lesions in DWI, as well as introduce bias and variability in quantitative diffusion measures. Consequently, the lack of blood suppression in motion moment-nulled DWI techniques may hinder their clinical applicability for liver DWI.

}, author = {Yuxin Zhang and {\'O}scar Pe{\~n}a-Nogales and James H. Holmes and Diego Hernando} } @conference {804, title = {Mapping Raw Acceleration Data on ActiGraph Counts: A Machine Learning Approach}, booktitle = {Proceedings of the Sixth International Conference on Technological Ecosystems for Enhancing Multiculturality}, year = {2018}, publisher = {ACM}, organization = {ACM}, address = {New York, NY, USA}, keywords = {ActiGraph, Actimetry, Microsoft Band 2, counts}, isbn = {978-1-4503-6518-5}, doi = {10.1145/3284179.3284260}, url = {http://doi.acm.org/10.1145/3284179.3284260}, author = {Mart{\'\i}n-Gonz{\'a}lez, Elena and Rodrigo de Luis-Garc{\'\i}a and Pablo Casaseca-de-la-Higuera and Garmendia-Leiza, J. R. and Jesus Maria Andres-de-Llano and Alberola-L{\'o}pez, Carlos} } @article {773, title = {Matching pursuit-based compressive sensing in a wearable biomedical accelerometer fall diagnosis device}, journal = {Biomedical signal processing and control}, volume = {33}, year = {2017}, pages = {96{\textendash}108}, author = {Gibson, Ryan M and Amira, Abbes and Ramzan, Naeem and Pablo Casaseca-de-la-Higuera and Pervez, Zeeshan} } @proceedings {725, title = {Monte-Carlo Analysis of Quantitative Diffusion Measurements Using Motion-Compensated Diffusion Weighting Waveforms}, year = {2017}, pages = {1733}, address = {Honolulu, HI, USA}, abstract = {

Advanced diffusion MRI acquisition strategies based on motion-compensated diffusion-econding waveforms have been proposed to reduce the signal voids caused by tissue motion. However, quantitative diffusion measurements obtained from these motion-compensated waveforms may be baised relative to standard monopolar gradient waveforms. This study evaluated the effect of different diffusion encoding gradient waveforms on the signal decay and diffusion measurements, using Monte-Carlo simulations with different microstructures and several reconstruction signal models. The results show substantial bias in observed signal decay and quantiative diffusion measurements in the same microstructure across different gradient waveforms, in the presence of restricted diffusion.

}, author = {Yuxin Zhang and {\'O}scar Pe{\~n}a-Nogales and James H. Holmes and Diego Hernando} } @article {597, title = {Multi-oriented windowed harmonic phase reconstruction for robust cardiac strain imaging}, journal = {Medical Image Analysis}, volume = {29}, year = {2016}, month = {2016}, pages = {1-11}, chapter = {1}, author = {Lucilio Cordero-Grande and J Royuela-del-Val and Santiago Sanz-Est{\'e}banez and Marcos Martin-Fernandez and Carlos Alberola-Lopez} } @article {776, title = {Multiple comparator classifier framework for accelerometer-based fall detection and diagnostic}, journal = {Applied Soft Computing}, volume = {39}, year = {2016}, pages = {94{\textendash}103}, author = {Gibson, Ryan M and Amira, Abbes and Ramzan, Naeem and Pablo Casaseca-de-la-Higuera and Pervez, Zeeshan} } @conference {603, title = {Multiresolution Reconstruction of Real-Time MRI with Motion Compensated Compressed Sensing: Application to 2D Free-Breathing Cardiac MRI}, booktitle = {International Symposium on Biomedical Engineering: From Nano to Macro}, year = {2016}, month = {2016}, publisher = {IEEE Signal Processing Society}, organization = {IEEE Signal Processing Society}, address = {Prague, Check Republic}, abstract = {

Real-time MRI is a novel noninvasive imaging technique that allows the visualization of physiological processes with both good spatial and temporal resolutions. However, the reconstruction of images from highly undersampled data, needed to perform real-time imaging, remains challenging. Recently, the combination of Compressed Sensing theory with motion compensation techniques has shown to achieve better results than previous methods. In this work we describe a real-time MRI algorithm based on the acquisition of the k-space data following a Golden Radial trajectory, Compressed Sensing reconstruction and a groupwise temporal registration algorithm for the estimation and compensation of the motion in the image, all this embedded within a temporal multiresolution scheme. We have applied the proposed method to the reconstruction of free-breathing acquisition of short axis views of the heart, achieving a temporal resolution of 25ms, corresponding to an acceleration factor of 28 with respect to fully sampled Cartesian acquisitions.

}, keywords = {Compressive sensing \& sampling, Image reconstruction {\textendash} analytical \& iterative methods, Magnetic resonance imaging (MRI)}, author = {J Royuela-del-Val and Muhammad Usman and Lucilio Cordero-Grande and M. Mart{\'\i}n-Fern{\'a}ndez and Federico Simmross-Wattenberg and Claudia Prieto and Carlos Alberola-Lopez} } @article {541, title = {A Maximum Likelihood Approach to Diffeomorphic Speckle Tracking for 3D Strain Estimation in Echocardiography}, journal = {Medical Image Analysis}, year = {2015}, pages = {-}, abstract = {

Abstract The strain and strain-rate measures are commonly used for the analysis and assessment of regional myocardial function. In echocardiography (EC), the strain analysis became possible using Tissue Doppler Imaging (TDI). Unfortunately, this modality shows an important limitation: the angle between the myocardial movement and the ultrasound beam should be small to provide reliable measures. This constraint makes it difficult to provide strain measures of the entire myocardium. Alternative non-Doppler techniques such as Speckle Tracking (ST) can provide strain measures without angle constraints. However, the spatial resolution and noisy appearance of speckle still make the strain estimation a challenging task in EC. Several maximum likelihood approaches have been proposed to statistically characterize the behavior of speckle, which results in a better performance of speckle tracking. However, those models do not consider common transformations to achieve the final B-mode image (e.g. interpolation). This paper proposes a new maximum likelihood approach for speckle tracking which effectively characterizes speckle of the final B-mode image. Its formulation provides a diffeomorphic scheme than can be efficiently optimized with a second-order method. The novelty of the method is threefold: First, the statistical characterization of speckle generalizes conventional speckle models (Rayleigh, Nakagami and Gamma) to a more versatile model for real data. Second, the formulation includes local correlation to increase the efficiency of frame-to-frame speckle tracking. Third, a probabilistic myocardial tissue characterization is used to automatically identify more reliable myocardial motions. The accuracy and agreement assessment was evaluated in a set of 16 synthetic image sequences for three different scenarios: normal, acute ischemia and acute dyssynchrony. The proposed method was compared to six speckle tracking methods. Results revealed that the proposed method is the most accurate method to measure the motion and strain with an average median motion error of 0.42\ mm and a median strain error of 2.0 {\textpm} 0.9\%, 2.1 {\textpm} 1.3\% and 7.1 {\textpm} 4.9\% for circumferential, longitudinal and radial strain respectively. It also showed its capability to identify abnormal segments with reduced cardiac function and timing differences for the dyssynchrony cases. These results indicate that the proposed diffeomorphic speckle tracking method provides robust and accurate motion and strain estimation.

}, doi = {http://dx.doi.org/10.1016/j.media.2015.05.001}, url = {http://www.sciencedirect.com/science/article/pii/S1361841515000687}, author = {Ariel H. Curiale and Gonzalo Vegas-S{\'a}nchez-Ferrero and Johan G. Bosch and Santiago Aja-Fern{\'a}ndez} } @article {573, title = {Multiple Comparator Classifier Framework for Accelerometer-Based Fall Detection and Diagnostic}, journal = {Applied Soft Computing}, year = {2015}, month = {In press}, author = {Gibson, Ryan M and Amira, Abbes and Ramzan, Naeem and Pablo Casaseca-de-la-Higuera and Pervez, Zeeshan} } @conference {588, title = {Multiresolution Reconstruction of Real-Time MRI with Motion Compensated Compressed Sensing: Application to 2D Free-Breathing Cardiac MRI}, booktitle = {XXXIII Congreso Anual de la Sociedad Espa{\~n}ola de Ingenier{\'\i}a Biom{\'e}dica (CASEIB)}, year = {2015}, month = {11/2015}, address = {Madrid}, author = {J Royuela-del-Val and Muhammad Usman and Lucilio Cordero-Grande and Marcos Martin-Fernandez and Federico Simmross-Wattenberg and Claudia Prieto and Carlos Alberola-Lopez} } @conference {426, title = {MOWHARP: Multi-Oriented Windowed HARP Reconstruction for Robust Strain Imaging}, booktitle = {Proceedings of the International Society for Magnetic Resonance in Medicine 22}, year = {2014}, author = {Lucilio Cordero-Grande and J Royuela-del-Val and Marcos Martin-Fernandez and Carlos Alberola-Lopez} } @article {445, title = {Multi-stencil streamline fast marching: a general 3D framework to determine myocardial thickness and transmurality in late enhancement images}, journal = {Medical Imaging, IEEE Transactions on}, volume = {33}, year = {2014}, pages = {23{\textendash}37}, author = {S. Merino-Caviedes and Lucilio Cordero-Grande and A. Revilla-Orodea and Perez, M. T. and Marcos Martin-Fernandez and Carlos Alberola-Lopez} } @conference {tristan2013merging, title = {Merging squared-magnitude approaches to DWI denoising: An adaptive Wiener filter tuned to the anatomical contents of the image}, booktitle = {Engineering in Medicine and Biology Society (EMBC), 2013 35th Annual International Conference of the IEEE}, year = {2013}, pages = {507{\textendash}510}, publisher = {IEEE}, organization = {IEEE}, author = {Antonio Trist{\'a}n-Vega and V{\'e}ronique Brion and Gonzalo Vegas-S{\'a}nchez-Ferrero and Santiago Aja-Fern{\'a}ndez} } @article {cordero2013magnetic, title = {A magnetic resonance software simulator for the evaluation of myocardial deformation estimation}, journal = {Medical engineering \& physics}, volume = {35}, number = {9}, year = {2013}, pages = {1331{\textendash}1340}, publisher = {Elsevier}, author = {Lucilio Cordero-Grande and Gonzalo Vegas-S{\'a}nchez-Ferrero and Pablo Casaseca-de-la-Higuera and Santiago Aja-Fern{\'a}ndez and Carlos Alberola-Lopez} } @conference {aja2012mri, title = {A MRI phantom for cardiac perfusion simulation}, booktitle = {Biomedical Imaging (ISBI), 2012 9th IEEE International Symposium on}, year = {2012}, pages = {638{\textendash}641}, publisher = {IEEE}, organization = {IEEE}, author = {Santiago Aja-Fern{\'a}ndez and Lucilio Cordero-Grande and Carlos Alberola-Lopez} } @article {cordero2012markov, title = {A Markov random field approach for topology-preserving registration: Application to object-based tomographic image interpolation}, journal = {Image Processing, IEEE Transactions on}, volume = {21}, number = {4}, year = {2012}, pages = {2047{\textendash}2061}, publisher = {IEEE}, author = {Lucilio Cordero-Grande and Gonzalo Vegas-S{\'a}nchez-Ferrero and Pablo Casaseca-de-la-Higuera and Carlos Alberola-Lopez} } @proceedings {580, title = {M{\'e}todos de an{\'a}lisis autom{\'a}tico de la actividad diaria del ni{\~n}o con TDAH. Mesa Redonda. Ponencia Invitada}, volume = {61}, year = {2012}, pages = {43-49}, address = {Granada, Spain}, author = {Pablo Casaseca-de-la-Higuera and Diego Mart{\'\i}n-Mart{\'\i}nez and Susana Alberola-Lopez and Jesus Maria Andres-de-Llano and L{\'o}pez-Villalobos, Jos{\'e} Antonio and Julio Ardura-Fernández and Carlos Alberola-Lopez} } @proceedings {584, title = {Modelado Estad{\'\i}stico de Se{\~n}ales Fotopletismogr{\'a}ficas para la Construcci{\'o}n de Atlas Poblacionales Orientados a la Evaluaci{\'o}n y Seguimiento del Remodelado Cardiovascular}, volume = {29}, year = {2011}, pages = {607-610}, address = {C{\'a}ceres, Spain}, author = {Diego Mart{\'\i}n-Mart{\'\i}nez and Pablo Casaseca-de-la-Higuera and Mart{\'\i}n Fern{\'a}ndez, Marcos and Carlos Alberola-Lopez} } @conference {merino2010multiphase, title = {Multiphase level set algorithm for coupled segmentation of multiple regions. Application to MRI segmentation}, booktitle = {Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE}, year = {2010}, pages = {5042{\textendash}5045}, publisher = {IEEE}, organization = {IEEE}, author = {S. Merino-Caviedes and P{\'e}rez, Mar{\'\i}a Teresa and Marcos Martin-Fernandez} } @article {casaseca2009multichannel, title = {A multichannel model-based methodology for extubation readiness decision of patients on weaning trials}, journal = {Biomedical Engineering, IEEE Transactions on}, volume = {56}, number = {7}, year = {2009}, pages = {1849{\textendash}1863}, publisher = {IEEE}, author = {Pablo Casaseca-de-la-Higuera and Federico Simmross-Wattenberg and Marcos Martin-Fernandez and Carlos Alberola-Lopez} } @article {477, title = {A multidimensional segmentation evaluation for medical image data}, journal = {Computer methods and programs in biomedicine}, volume = {96}, year = {2009}, pages = {108{\textendash}124}, abstract = {

Evaluation of segmentation methods is a crucial aspect in image processing, especially in the medical imaging field, where small differences between segmented regions in the anatomy can be of paramount importance. Usually, segmentation evaluation is based on a measure that depends on the number of segmented voxels inside and outside of some reference regions that are called gold standards. Although some other measures have been also used, in this work we propose a set of new similarity measures, based on different features, such as the location and intensity values of the misclassified voxels, and the connectivity and the boundaries of the segmented data. Using the multidimensional information provided by these measures, we propose a new evaluation method whose results are visualized applying a Principal Component Analysis of the data, obtaining a simplified graphical method to compare different segmentation results. We have carried out an intensive study using several classic segmentation methods applied to a set of MRI simulated data of the brain with several noise and RF inhomogeneity levels, and also to real data, showing that the new measures proposed here and the results that we have obtained from the multidimensional evaluation, improve the robustness of the evaluation and provides better understanding about the difference between segmentation methods.

}, author = {Rub{\'e}n C{\'a}rdenes-Almeida and Rodrigo de Luis-Garc{\'\i}a and Bach-Cuadra, Meritxell} } @article {aja2008matrix, title = {Matrix modeling of hierarchical fuzzy systems}, journal = {Fuzzy Systems, IEEE Transactions on}, volume = {16}, number = {3}, year = {2008}, pages = {585{\textendash}599}, publisher = {IEEE}, author = {Santiago Aja-Fern{\'a}ndez and Carlos Alberola-Lopez} } @proceedings {simmross2008modelling, title = {Modelling Network Traffic as alpha-Stable Stochastic Processes: An Approach Towards Anomaly Detection}, year = {2008}, pages = {25{\textendash}32}, author = {Federico Simmross-Wattenberg and Antonio Trist{\'a}n-Vega and Pablo Casaseca-de-la-Higuera and Juan Ignacio Asensio-P{\'e}rez and Marcos Martin-Fernandez and Yannis A Dimitriadis and Carlos Alberola-Lopez} } @conference {muoz2008methodology, title = {A methodology for quality assessment in tensor images}, booktitle = {Computer Vision and Pattern Recognition Workshops, 2008. CVPRW{\textquoteright}08. IEEE Computer Society Conference on}, year = {2008}, pages = {1{\textendash}6}, publisher = {IEEE}, organization = {IEEE}, author = {Emma Mu{\~n}oz-Moreno and Santiago Aja-Fern{\'a}ndez and Marcos Martin-Fernandez} } @inbook {de2007mixtures, title = {Mixtures of gaussians on tensor fields for DT-MRI segmentation}, booktitle = {Medical Image Computing and Computer-Assisted Intervention{\textendash}MICCAI 2007}, year = {2007}, pages = {319{\textendash}326}, publisher = {Springer}, organization = {Springer}, author = {Rodrigo de Luis-Garc{\'\i}a and Carlos Alberola-Lopez} } @conference {480, title = {Multimodal evaluation for medical image segmentation}, booktitle = {Computer Analysis of Images and Patterns}, year = {2007}, publisher = {Springer}, organization = {Springer}, author = {Rub{\'e}n C{\'a}rdenes-Almeida and Bach, Meritxell and Chi, Ying and Marras, Ioannis and Rodrigo de Luis-Garc{\'\i}a and Anderson, Mats and Cashman, Peter and Bultelle, Matthieu} } @conference {aja2005matrix, title = {Matrix Inference in Fuzzy Decision Trees.}, booktitle = {EUSFLAT Conf.}, year = {2005}, pages = {979{\textendash}984}, author = {Santiago Aja-Fern{\'a}ndez and Carlos Alberola-Lopez} } @article {420, title = {A model selection algorithm for a posteriori probability estimation with neural networks}, journal = {IEEE Transactions on Neural Networks}, volume = {16}, year = {2005}, pages = {799-809}, abstract = {

This paper proposes a novel algorithm to jointly determine the structure and the parameters of a posteriori probability model based on neural networks (NNs). It makes use of well-known ideas of pruning, splitting, and merging neural components and takes advantage of the probabilistic interpretation of these components. The algorithm, so called a posteriori probability model selection (PPMS), is applied to an NN architecture called the generalized softmax perceptron (GSP) whose outputs can be understood as probabilities although results shown can be extended to more general network architectures. Learning rules are derived from the application of the expectation-maximization algorithm to the GSP-PPMS structure. Simulation results show the advantages of the proposed algorithm with respect to other schemes. {\^A}{\textcopyright} 2005 IEEE.

}, keywords = {Algorithms, Automated, Biological, Breast Neoplasms, Computer simulation, Computer-Assisted, Computing Methodologies, Decision Support Techniques, Diagnosis, Estimation, Expectation-maximization, Generalized Softmax Perceptron (GSP), Humans, Mathematical models, Model selection, Models, Neural Networks (Computer), Neural networks, Numerical Analysis, Objective function, Pattern recognition, Posterior probability, Probability, Statistical, Stochastic Processes, algorithm, article, artificial neural network, automated pattern recognition, biological model, breast tumor, classification, cluster analysis, computer analysis, computer assisted diagnosis, decision support system, evaluation, human, mathematical computing, methodology, statistical model, statistics}, issn = {10459227}, doi = {10.1109/TNN.2005.849826}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-23044459586\&partnerID=40\&md5=f00e7d86a625cfc466373a2a938276d0}, author = {J I Arribas and Jes{\'u}s Cid-Sueiro} } @proceedings {de2003model, title = {A model-based algorithm for the automatic segmentation of metacarpals in handwrist radiographs using active contours}, year = {2003}, pages = {80{\textendash}81}, author = {Rodrigo de Luis-Garc{\'\i}a and Marcos Martin-Fernandez and Miguel Angel Martin-Fernandez and Carlos Alberola-Lopez} } @conference {martin2001maximum, title = {Maximum likelihood contour estimation using beta-statistics in ultrasound images}, booktitle = {Image and Signal Processing and Analysis, 2001. ISPA 2001. Proceedings of the 2nd International Symposium on}, year = {2001}, pages = {207{\textendash}212}, publisher = {IEEE}, organization = {IEEE}, author = {Marcos Martin-Fernandez and Raul San Jose-Estepar and Carlos Alberola-Lopez} } @conference {martin2001multiresolution, title = {Multiresolution compression schemes for medical image and volume data}, booktitle = {Engineering in Medicine and Biology Society, 2001. Proceedings of the 23rd Annual International Conference of the IEEE}, volume = {3}, year = {2001}, pages = {2437{\textendash}2440}, publisher = {IEEE}, organization = {IEEE}, author = {Miguel Angel Martin-Fernandez and Carlos Alberola-Lopez and Sanz de Acedo, Jorge and Juan Ruiz-Alzola} } @article {ruiz2000model, title = {Model-based stereo-visual tracking: Covariance analysis and tracking schemes}, journal = {Signal Processing}, volume = {80}, number = {1}, year = {2000}, pages = {23{\textendash}43}, publisher = {Elsevier}, author = {Juan Ruiz-Alzola and Carlos Alberola-Lopez and Corredera, Jose-Ram{\'o}n Casar} } @conference {tardon1999markov, title = {Markov random fields and the disparity gradient constraint applied to stereo correspondence}, booktitle = {Image Processing, 1999. ICIP 99. Proceedings. 1999 International Conference on}, volume = {3}, year = {1999}, pages = {901{\textendash}905}, publisher = {IEEE}, organization = {IEEE}, author = {Lorenzo J Tard{\'o}n-Garc{\'\i}a and Javier Portillo-Garcia and Carlos Alberola-Lopez} }