|
|
Ferran Poveda, Jaume Garcia, Enric Marti, & Debora Gil. (2010). "Validation of the myocardial architecture in DT-MRI tractography " In Medical Image Computing in Catalunya: Graduate Student Workshop (pp. 29–30). Girona (Spain).
Abstract: Deep understanding of myocardial structure may help to link form and funcion of the heart unraveling crucial knowledge for medical and surgical clinical procedures and studies. In this work we introduce two visualization techniques based on DT-MRI streamlining able to decipher interesting properties of the architectural organization of the heart.
|
|
|
|
Oriol Rodriguez-Leon, Debora Gil, Eduard Fernandez-Nofrerias, H.Tizon, S.Montserrat, Vicente del Valle, et al. (2007)." Caracterització de la Perfusió Miocàrdica mitjançant anàlisi estadístic de l espectre en l angiografia de contrast" In XIX Congrés de la Societat Catalana de Cardiologia de Barcelona (130). Barcelona (Spain).
Abstract: La valoració de la integritat de la microcirculació coronària aporta informació pronòstica en pacients amb infart agut de miocardi en els que es realitza angioplastia primària. Aquesta valoració és subjectiva i presenta una important variabilitat si no es duta a terme per personal experimentat. Presentem una eina d’anàlisi d’imatge que permet fer una valoració de la microcirculació coronària a partir de seqüències d’angiografia. Hem analitzat les variacions locals en el nivell de gris de la imatge durant la seqüència angiogràfica. Hem identificat els principals fenòmens observats (respiració, batec cardíac, tinció arterial, tinció miocàrdica i soroll radiològic) mitjançant un anàlisi estadístic de l’espectre de Fourier de l’evolució al llarg del temps de la mitja local. Aquest mateix anàlisis permet determinat la influència de cadascun d’ells en la extracció del patró de tinció i selecciona la respiració com el fenomen que més distorsiona el patró de tinció original. Els descriptors proposats s’obtenen fora del rang espectral respiratori. Hem testat la seva capacitat per a detectar els tres fenòmens principals (tinció miocàrdica (MS), tinció arterial (AS) i soroll (NS)) independentment de la respiració. La capacitat de discriminació dels descriptors ha estat valorada mitjançant un mètode de crossvalidation en 30 seqüències d’angiografia. Els descriptors emprats permeten caracteritzar la tinció miocàrdica amb una alta eficiència i fiabilitat. A més no hi ha diferències significatives en l’anàlisi de les seqüències obtingudes amb el pacient respirant amb normalitat o en apnea
|
|
|
|
David Roche, Debora Gil, & Jesus Giraldo. (2011). "An inference model for analyzing termination conditions of Evolutionary Algorithms " In 14th Congrès Català en Intel·ligencia Artificial (pp. 216–225).
Abstract: In real-world problems, it is mandatory to design a termination condition for Evolutionary Algorithms (EAs) ensuring stabilization close to the unknown optimum. Distribution-based quantities are good candidates as far as suitable parameters are used. A main limitation for application to real-world problems is that such parameters strongly depend on the topology of the objective function, as well as, the EA paradigm used.
We claim that the termination problem would be fully solved if we had a model measuring to what extent a distribution-based quantity asymptotically behaves like the solution accuracy. We present a regression-prediction model that relates any two given quantities and reports if they can be statistically swapped as termination conditions. Our framework is applied to two issues. First, exploring if the parameters involved in the computation of distribution-based quantities influence their asymptotic behavior. Second, to what extent existing distribution-based quantities can be asymptotically exchanged for the accuracy of the EA solution.
Keywords: Evolutionary Computation Convergence, Termination Conditions, Statistical Inference
|
|
|
|
Ferran Poveda, Debora Gil, Albert Andaluz, & Enric Marti. (2011). "Multiscale Tractography for Representing Heart Muscular Architecture " In In MICCAI 2011 Workshop on Computational Diffusion MRI.
Abstract: Deep understanding of myocardial structure of the heart would unravel crucial knowledge for clinical and medical procedures. Although the muscular architecture of the heart has been debated by countless researchers, the controversy is still alive. Diffusion Tensor MRI, DT-MRI, is a unique imaging technique for computational validation of the muscular structure of the heart. By the complex arrangement of myocites, existing techniques can not provide comprehensive descriptions of the global muscular architecture. In this paper we introduce a multiresolution reconstruction technique based on DT-MRI streamlining for simplified global myocardial model generation. Our reconstructions can restore the most complex myocardial structures and indicate a global helical organization
|
|
|
|
Debora Gil, Agnes Borras, Manuel Ballester, Francesc Carreras, Ruth Aris, Manuel Vazquez, et al. (2011). "MIOCARDIA: Integrating cardiac function and muscular architecture for a better diagnosis " In Association for Computing Machinery (Ed.), 14th International Symposium on Applied Sciences in Biomedical and Communication Technologies. Barcelona, Spain.
Abstract: Deep understanding of myocardial structure of the heart would unravel crucial knowledge for clinical and medical procedures. The MIOCARDIA project is a multidisciplinary project in cooperation with l'Hospital de la Santa Creu i de Sant Pau, Clinica la Creu Blanca and Barcelona Supercomputing Center. The ultimate goal of this project is defining a computational model of the myocardium. The model takes into account the deep interrelation between the anatomy and the mechanics of the heart. The paper explains the workflow of the MIOCARDIA project. It also introduces a multiresolution reconstruction technique based on DT-MRI streamlining for simplified global myocardial model generation. Our reconstructions can restore the most complex myocardial structures and provides evidences of a global helical organization.
|
|
|
|
David Roche, Debora Gil, & Jesus Giraldo. (2012). "Assessing agonist efficacy in an uncertain Em world " In A. Christopoulus and M. Bouvier (Ed.), 40th Keystone Symposia on mollecular and celular biology (79). Keystone Symposia.
Abstract: The operational model of agonism has been widely used for the analysis of agonist action since its formulation in 1983. The model includes the Em parameter, which is defined as the maximum response of the system. The methods for Em estimation provide Em values not significantly higher than the maximum responses achieved by full agonists. However, it has been found that that some classes of compounds as, for instance, superagonists and positive allosteric modulators can increase the full agonist maximum response, implying upper limits for Em and thereby posing doubts on the validity of Em estimates. Because of the correlation between Em and operational efficacy, τ, wrong Em estimates will yield wrong τ estimates.
In this presentation, the operational model of agonism and various methods for the simulation of allosteric modulation will be analyzed. Alternatives for curve fitting will be presented and discussed.
|
|
|
|
Patricia Marquez, Debora Gil, & Aura Hernandez-Sabate. (2012). "Error Analysis for Lucas-Kanade Based Schemes " In 9th International Conference on Image Analysis and Recognition (Vol. 7324, pp. 184–191). Lecture Notes in Computer Science. Springer-Verlag Berlin Heidelberg.
Abstract: Optical flow is a valuable tool for motion analysis in medical imaging sequences. A reliable application requires determining the accuracy of the computed optical flow. This is a main challenge given the absence of ground truth in medical sequences. This paper presents an error analysis of Lucas-Kanade schemes in terms of intrinsic design errors and numerical stability of the algorithm. Our analysis provides a confidence measure that is naturally correlated to the accuracy of the flow field. Our experiments show the higher predictive value of our confidence measure compared to existing measures.
Keywords: Optical flow, Confidence measure, Lucas-Kanade, Cardiac Magnetic Resonance
|
|
|
|
Albert Andaluz, Francesc Carreras, Cristina Santa Marta, & Debora Gil. (2012). "Myocardial torsion estimation with Tagged-MRI in the OsiriX platform " In Wiro Niessen(Erasmus MC) and Marc Modat(UCL) (Ed.), ISBI Workshop on Open Source Medical Image Analysis software. IEEE.
Abstract: Myocardial torsion (MT) plays a crucial role in the assessment of the functionality of the
left ventricle. For this purpose, the IAM group at the CVC has developed the Harmonic Phase Flow (HPF) plugin for the Osirix DICOM platform . We have validated its funcionalty on sequences acquired using different protocols and including healthy and pathological cases. Results show similar torsion trends for SPAMM acquisitions, with pathological cases introducing expected deviations from the ground truth. Finally, we provide the plugin free of charge at http://iam.cvc.uab.es
|
|
|
|
A. M. Here, B. C. Lopez, Debora Gil, J. J. Camarero, & Jordi Martinez-Vilalta. (2013). "A new software to analyse wood anatomical features in conifer species " In International Symposium on Wood Structure in Plant Biology and Ecology.
Abstract: International Symposium on Wood Structure in Plant Biology and Ecology
|
|
|
|
Sergio Vera, Miguel Angel Gonzalez Ballester, & Debora Gil. (2013). "Volumetric Anatomical Parameterization and Meshing for Inter-patient Liver Coordinate System Deffinition " In 16th International Conference on Medical Image Computing and Computer Assisted Intervention.
|
|
