@article {960, title = {Fast 4D elastic group-wise image registration. Convolutional interpolation revisited}, journal = {Computer Methods and Programs in Biomedicine}, volume = {200}, year = {2021}, pages = {105812}, abstract = {

Background and Objective:This paper proposes a new and highly efficient implementation of 3D+t groupwise registration based on the free-form deformation paradigm. Methods:Deformation is posed as a cascade of 1D convolutions, achieving great reduction in execution time for evaluation of transformations and gradients. Results:The proposed method has been applied to 4D cardiac MRI and 4D thoracic CT monomodal datasets. Results show an average runtime reduction above 90\%, both in CPU and GPU executions, compared with the classical tensor product formulation. Conclusions:Our implementation, although fully developed for the metric sum of squared differences, can be extended to other metrics and its adaptation to multiresolution strategies is straightforward. Therefore, it can be extremely useful to speed up image registration procedures in different applications where high dimensional data are involved.

}, keywords = {B-splines, Convolution, Efficient implementation, Free-form deformation, Groupwise Registration, Non-rigid registration}, issn = {0169-2607}, doi = {https://doi.org/10.1016/j.cmpb.2020.105812}, url = {https://www.sciencedirect.com/science/article/pii/S016926072031645X}, author = {Rosa-Mar{\'\i}a Mench{\'o}n-Lara and Javier Royuela-del-Val and Federico Simmross-Wattenberg and Pablo Casaseca-de-la-Higuera and Marcos Mart{\'\i}n-Fern{\'a}ndez and Carlos Alberola-L{\'o}pez} } @article {807, title = {OpenCLIPER: An OpenCL-Based C++ Framework for Overhead-Reduced Medical Image Processing and Reconstruction on Heterogeneous Devices}, journal = {IEEE Journal of Biomedical and Health Informatics}, volume = {23}, year = {2019}, month = {July}, pages = {1702-1709}, abstract = {

Medical image processing is often limited by the computational cost of the involved algorithms. Whereas dedicated computing devices (GPUs in particular) exist and do provide significant efficiency boosts, they have an extra cost of use in terms of housekeeping tasks (device selection and initialization, data streaming, synchronization with the CPU, and others), which may hinder developers from using them. This paper describes an OpenCL-based framework that is capable of handling dedicated computing devices seamlessly and that allows the developer to concentrate on image processing tasks. The framework handles automatically device discovery and initialization, data transfers to and from the device and the file system and kernel loading and compiling. Data structures need to be defined only once independently of the computing device; code is unique, consequently, for every device, including the host CPU. Pinned memory/buffer mapping is used to achieve maximum performance in data transfers. Code fragments included in the paper show how the computing device is almost immediately and effortlessly available to the users algorithms, so they can focus on productive work. Code required for device selection and initialization, data loading and streaming and kernel compilation is minimal and systematic. Algorithms can be thought of as mathematical operators (called processes), with input, output and parameters, and they may be chained one after another easily and efficiently. Also for efficiency, processes can have their initialization work split from their core workload, so process chains and loops do not incur in performance penalties. Algorithm code is independent of the device type targeted.

}, keywords = {C++, C++ languages, Data structures, GPU, Graphics processing units, Image reconstruction, Informatics, Kernel, Libraries, Medical imaging, OpenCL}, issn = {2168-2194}, doi = {10.1109/JBHI.2018.2869421}, author = {Federico Simmross-Wattenberg and M. Rodr{\'\i}guez-Cayetano and J Royuela-del-Val and E. Mart{\'\i}n-Gonz{\'a}lez and E. Moya-S{\'a}ez and M. Mart{\'\i}n-Fern{\'a}ndez and C. Alberola-L{\'o}pez} } @article {743, title = {Libstable: Fast, parallel, and high-precision computation of α-stable distributions in R, C/C++, and MATLAB}, journal = {Journal of Statistical Software}, volume = {78}, year = {2017}, pages = {1-25}, doi = {10.18637/jss.v078.i01}, author = {J Royuela-del-Val and Federico Simmross-Wattenberg and Carlos Alberola-Lopez} } @conference {663, title = {Cardio-respiratory motion estimation for compressed sensing reconstruction of free-breathing 2D cine MRI}, booktitle = {Modulated/Incomplete Data 2016, SFB Workshop.}, year = {2016}, month = {2016}, publisher = {Mathematical Optimization and Applications in Biomedical Sciences (MOBIS), SFB Research Center}, organization = {Mathematical Optimization and Applications in Biomedical Sciences (MOBIS), SFB Research Center}, address = {Graz, Austria}, abstract = {

Respiratory motion is still an issue in MRI of the heart despite the introduction of Compressed Sensing (CS) techniques, which significantly accelerate acquisition [1]. Recently [2], a double-binning scheme was introduced in which k-space data is split according both to the cardiac and respiratory phases (Fig. 1); at reconstruction, sparsity along both dimensions is exploited. Other methods introduce motion estimation and compensation in CS (MC-CS) either to correct the respiratory motion [3] or to promote sparsity for reconstruction improvement [4]. In this work, we propose a technique to jointly estimate the respiratory and cardiac motions within a double-binning scheme, enabling the MC-CS reconstruction of respiratory resolved free-breathing 2D CINE MRI. Preliminary results on synthetic, highly undersampled (x16) Cartesian setup are shown.

[1] Lustig et al. MRM 2007, [2] Feng et al. MRM 2015, [3] Usman et al. MRM 2013. [4]\ Royuela-del-Val et al. MRM 2015.

}, author = {J Royuela-del-Val and Marcos Mart{\'\i}n-Fern{\'a}ndez and Federico Simmross-Wattenberg and Carlos Alberola-Lopez} } @article {602, title = {Jacobian weighted temporal total variation for motion compensated compressed sensing reconstruction of dynamic MRI}, journal = {Magnetic Resonance in Medicine}, year = {2016}, month = {2016}, abstract = {

Purpose:\ To eliminate the need of spatial intraframe regularization in a recently reported dynamic MRI compressed-sensing-based reconstruction method with motion compensation and to increase its performance.

Theory and Methods: We propose a new regularization metric based on the introduction of a spatial weighting measure given by the Jacobian of the estimated deformations. It shows convenient discretization properties and, as a byproduct, it also provides a theoretical support to a result reported by others based on an intuitive design. The method has been applied to the reconstruction of both short and long axis views of the heart of four healthy volunteers. Quantitative image quality metrics as well as straightforward visual assessment are reported.

Results: Short and long axis reconstructions of cardiac cine MRI sequences have shown superior results than previously reported methods both in terms of quantitative metrics and of visual assessment. Fine details are better preserved due to the lack of additional intraframe regularization, with no significant image artifacts even for an acceleration factor of 12.

Conclusions: The proposed Jacobian Weighted temporal Total Variation results in better reconstructions of highly undersampled cardiac cine MRI than previously proposed methods and sets a theoretical ground for forward and backward predictors used elsewhere.

}, keywords = {compressed sensing, dynamic MRI reconstruction, group-wise registration, motion estimation}, doi = {10.1002/mrm.26198}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mrm.26198}, author = {J Royuela-del-Val and Lucilio Cordero-Grande and Federico Simmross-Wattenberg and Mart{\'\i}n-Fern{\'a}ndez, M and Carlos Alberola-Lopez} } @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} } @conference {690, title = {Whole-heart single breath-hold cardiac cine: A robust motion-compensated compressed sensing reconstruction method}, booktitle = {International Workshop on Reconstruction and Analysis of Moving Body Organs (RAMBO/MICCAI) }, year = {2016}, month = {2016}, address = {Athens, Greece}, author = {J Royuela-del-Val and Muhammad Usman and Lucilio Cordero-Grande and Marcos Mart{\'\i}n-Fern{\'a}ndez and Federico Simmross-Wattenberg and Claudia Prieto and Carlos Alberola-Lopez} } @article {431, title = {Fast calculation of alpha-stable density functions based on off-line precomputations. Application to ML parameter estimation}, journal = {Digital Signal Processing}, volume = {38}, year = {2015}, pages = {1-12}, chapter = {1}, keywords = {Delaunay triangulation, Interpolation, Parameter estimation, alpha-Stable}, doi = {10.1016/j.dsp.2014.12.009}, author = {Federico Simmross-Wattenberg and Marcos Mart{\'\i}n-Fern{\'a}ndez and Pablo Casaseca-de-la-Higuera and Carlos Alberola-Lopez} } @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} } @article {533, title = {Non-Rigid Groupwise Registration for Motion Estimation and Compensation in Compressed Sensing Reconstruction of Breath-Hold Cardiac Cine MRI}, journal = {Magnetic Resonance in Medicine}, year = {2015}, doi = {10.1002/mrm.25733}, author = {J Royuela-del-Val and Lucilio Cordero-Grande and Federico Simmross-Wattenberg and Marcos Mart{\'\i}n-Fern{\'a}ndez and Carlos Alberola-Lopez} } @conference {520, title = {Single Breath Hold Whole Heart Cine MRI With Iterative Groupwise Cardiac Motion Compensation and Sparse Regularization (kt-WiSE)}, booktitle = {Proceedings of the International Society for Magnetic Resonance in Medicine 23}, year = {2015}, author = {J Royuela-del-Val and Muhammad Usman and Lucilio Cordero-Grande and Federico Simmross-Wattenberg and Marcos Martin-Fern{\'a}ndez and Claudia Prieto and Carlos Alberola-Lopez} } @conference {436, title = {Comparativa entre distribuciones alpha-estables para modelar tasas de transferencia obtenidas a partir de registros de SNMP y NetFlow}, booktitle = {Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL)}, year = {2013}, publisher = {Asociaci{\'o}n de Telem{\'a}tica (ATEL)}, organization = {Asociaci{\'o}n de Telem{\'a}tica (ATEL)}, address = {Granada, Spain}, author = {Stoppa, Matteo and L{\'o}pez-de-Vergara-M{\'e}ndez, Jorge E. and Federico Simmross-Wattenberg and Garc{\'\i}a-Dorado, Jos{\'e} Luis} } @conference {435, title = {Caracterizaci{\'o}n de speckle con modelos de cola pesada}, booktitle = {Congreso Anual de la Sociedad Espa{\~n}ola de Ingenier{\'\i}a Biom{\'e}dica (CASEIB)}, year = {2012}, publisher = {Sociedad Espa{\~n}ola de Ingenier{\'\i}a Biom{\'e}dica}, organization = {Sociedad Espa{\~n}ola de Ingenier{\'\i}a Biom{\'e}dica}, address = {San Sebasti{\'a}n, Espa{\~n}a}, author = {Gonzalo Vegas-S{\'a}nchez-Ferrero and Federico Simmross-Wattenberg and Marcos Martin-Fernandez and Palencia-de-Lara, C{\'e}sar and Carlos Alberola-Lopez} } @conference {434, title = {Dise{\~n}o e implementaci{\'o}n de plugins en el entorno GIMIAS para procesado y visualizaci{\'o}n de se{\~n}ales electrofisiol{\'o}gicas asociadas a problemas cardiovasculares}, booktitle = {Congreso Anual de la Sociedad Espa{\~n}ola de Ingenier{\'\i}a Biom{\'e}dica (CASEIB)}, year = {2012}, publisher = {Sociedad Espa{\~n}ola de Ingenier{\'\i}a Biom{\'e}dica}, organization = {Sociedad Espa{\~n}ola de Ingenier{\'\i}a Biom{\'e}dica}, address = {San Sebasti{\'a}n, Espa{\~n}a}, author = {Mart{\'\i}n-Hern{\'a}ndez, Noelia and J Royuela-del-Val and Ver{\'o}nica Garc{\'\i}a-P{\'e}rez and Federico Simmross-Wattenberg and Marcos Martin-Fernandez and Carlos Alberola-Lopez} } @inbook {432, title = {Ubiquitous tele-monitoring kit (UTK): measuring physiological signals anywhere at anytime}, booktitle = {Ambient Assisted Living and Home Care}, year = {2012}, pages = {183{\textendash}191}, publisher = {Springer}, organization = {Springer}, author = {Marcos-Lagunar, Carlos and Cavero-Barca, Carlos and Quintero-Padr{\'o}n, Ana Mar{\'\i}a and Planes, Xavier and Federico Simmross-Wattenberg and Carlos Alberola-Lopez and Marcos Martin-Fernandez and Mart{\'\i}n-Hern{\'a}ndez, Noelia and Calder{\'o}n-Oliveras, Enric and Corral-Herranz, Javier and Gonz{\'a}lez-Mart{\'\i}nez, A. and Huguet, Jordi and Aguilar, Rosal{\'\i}a} } @article {193, title = {Anomaly detection in network traffic based on statistical inference and alpha-stable modeling}, journal = {Dependable and Secure Computing, IEEE Transactions on}, volume = {8}, year = {2011}, pages = {494{\textendash}509}, author = {Federico Simmross-Wattenberg and Juan Ignacio Asensio-P{\'e}rez and Pablo Casaseca-de-la-Higuera and Marcos Martin-Fernandez and Yannis A Dimitriadis and Carlos Alberola-Lopez} } @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} } @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} } @proceedings {433, title = {On the estimation of joint probability density functions for multi-modal registration of medical images}, volume = {26}, year = {2008}, pages = {13-16}, publisher = {Sociedad Espa{\~n}ola de Ingenier{\'\i}a Biom{\'e}dica}, address = {Valladolid, Spain}, author = {Antonio Trist{\'a}n-Vega and Federico Simmross-Wattenberg and Emma Mu{\~n}oz-Moreno and Pablo Casaseca-de-la-Higuera and Marcos Martin-Fernandez} } @article {palacios2005group, title = {Group-Slicer: A collaborative extension of 3D-Slicer}, journal = {Journal of Biomedical Informatics}, volume = {38}, year = {2005}, pages = {431{\textendash}442}, author = {Federico Simmross-Wattenberg and Palacios-Camarero, Cristina and Pablo Casaseca-de-la-Higuera and Miguel Angel Martin-Fernandez and Santiago Aja-Fern{\'a}ndez and Juan Ruiz-Alzola and Carl-Fredik Westin and Carlos Alberola-Lopez} } @conference {429, title = {Weaning from mechanical ventilation: feature extraction from a statistical signal processing viewpoint}, booktitle = {Proc. 13th Signal Processing Conf., EUSIPCO}, year = {2005}, author = {Pablo Casaseca-de-la-Higuera and Rodrigo de Luis-Garc{\'\i}a and Federico Simmross-Wattenberg and Carlos Alberola-Lopez} } @conference {430, title = {A lossless compression algorithm based on predictive coding for volumetric medical datasets}, booktitle = {Proc. EUSIPCO 2005}, year = {2005}, author = {D{\'\i}ez-Garc{\'\i}a, M{\'o}nica and Federico Simmross-Wattenberg and Carlos Alberola-Lopez} } @conference {428, title = {The opportunity of grid services for CSCL-application development}, booktitle = {Parallel, Distributed and Network-Based Processing, 2005. PDP 2005. 13th Euromicro Conference on}, year = {2005}, publisher = {IEEE}, organization = {IEEE}, address = {Lausanne, Switzerland}, author = {Vaquero-Gonz{\'a}lez, Luis M and Hern{\'a}ndez-Leo, D and Federico Simmross-Wattenberg and Bote-Lorenzo, Miguel L and Juan Ignacio Asensio-P{\'e}rez and Yannis A Dimitriadis and G{\'o}mez-S{\'a}nchez, Eduardo and Vega-Gorgojo, Guillermo} }