Santiago Aja-Fernandez

Summary

Affiliation: University of Valladolid
Country: Spain

Publications

  1. doi request reprint Soft thresholding for medical image segmentation
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid Spain
    Conf Proc IEEE Eng Med Biol Soc 2010:4752-5. 2010
  2. doi request reprint Noise estimation in parallel MRI: GRAPPA and SENSE
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Spain Electronic address
    Magn Reson Imaging 32:281-90. 2014
  3. doi request reprint Improving GRAPPA reconstruction by frequency discrimination in the ACS lines
    Santiago Aja-Fernandez
    Laboratorio de Procesado de Imagen LPI, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid, Spain
    Int J Comput Assist Radiol Surg 10:1699-710. 2015
  4. doi request reprint Spatially variant noise estimation in MRI: a homomorphic approach
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Spain Electronic address
    Med Image Anal 20:184-97. 2015
  5. doi request reprint Effective noise estimation and filtering from correlated multiple-coil MR data
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid 47011, Spain
    Magn Reson Imaging 31:272-85. 2013
  6. ncbi request reprint A computational TW3 classifier for skeletal maturity assessment. A Computing with Words approach
    Santiago Aja-Fernandez
    Laboratorio de Procesado de Imagen, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid, Spain
    J Biomed Inform 37:99-107. 2004
  7. doi request reprint DWI acquisition schemes and diffusion tensor estimation: a simulation-based study
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicación Universidad de Valladolid Spain
    Conf Proc IEEE Eng Med Biol Soc 2010:3317-20. 2010
  8. pmc Statistical noise analysis in GRAPPA using a parametrized noncentral Chi approximation model
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Spain
    Magn Reson Med 65:1195-206. 2011
  9. doi request reprint Influence of noise correlation in multiple-coil statistical models with sum of squares reconstruction
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Spain
    Magn Reson Med 67:580-5. 2012
  10. doi request reprint About the background distribution in MR data: a local variance study
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid, Spain
    Magn Reson Imaging 28:739-52. 2010

Collaborators

Detail Information

Publications30

  1. doi request reprint Soft thresholding for medical image segmentation
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid Spain
    Conf Proc IEEE Eng Med Biol Soc 2010:4752-5. 2010
    ..As a consequence, each pixel will belong to different regions with a different level of membership. This feature is exploited through spatial processing to make the thresholding robust to noisy environments...
  2. doi request reprint Noise estimation in parallel MRI: GRAPPA and SENSE
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Spain Electronic address
    Magn Reson Imaging 32:281-90. 2014
    ..In both cases, some additional information must be known beforehand: the sensitivity maps of each receiver coil in the SENSE case and the reconstruction coefficients for GRAPPA. ..
  3. doi request reprint Improving GRAPPA reconstruction by frequency discrimination in the ACS lines
    Santiago Aja-Fernandez
    Laboratorio de Procesado de Imagen LPI, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid, Spain
    Int J Comput Assist Radiol Surg 10:1699-710. 2015
    ..We propose a simple, yet powerful method to eliminate reconstruction artifacts, based on the discrimination of the low-frequency spectrum...
  4. doi request reprint Spatially variant noise estimation in MRI: a homomorphic approach
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Spain Electronic address
    Med Image Anal 20:184-97. 2015
    ..Results in real and synthetic experiments evidence the better performance and the lowest error variance of the proposed methodology when compared to the state-of-the-art methods. ..
  5. doi request reprint Effective noise estimation and filtering from correlated multiple-coil MR data
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid 47011, Spain
    Magn Reson Imaging 31:272-85. 2013
    ..At the same time, the proper statistical characterization of noise through effective parameters drives to improved accuracy (both qualitatively and quantitatively) for both of the problems studied...
  6. ncbi request reprint A computational TW3 classifier for skeletal maturity assessment. A Computing with Words approach
    Santiago Aja-Fernandez
    Laboratorio de Procesado de Imagen, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid, Spain
    J Biomed Inform 37:99-107. 2004
    ..e., to find out the classification rules, since the classifier is built upon rules given by the TW3 method. Only small data records are needed to fine-tune the fuzzy sets used to implement the rulebase...
  7. doi request reprint DWI acquisition schemes and diffusion tensor estimation: a simulation-based study
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicación Universidad de Valladolid Spain
    Conf Proc IEEE Eng Med Biol Soc 2010:3317-20. 2010
    ..Reconstructed subsampled data will show an acceleration in the acquisition process, but also greater variance and bias in the DT estimation...
  8. pmc Statistical noise analysis in GRAPPA using a parametrized noncentral Chi approximation model
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Spain
    Magn Reson Med 65:1195-206. 2011
    ..Extensive experiments over both synthetic and in vivo data sets have been performed to show the goodness of fit of out model...
  9. doi request reprint Influence of noise correlation in multiple-coil statistical models with sum of squares reconstruction
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Spain
    Magn Reson Med 67:580-5. 2012
    ..This implies a reduced effective number of coils and an increased effective variance of noise. In addition, the effective variance of noise becomes signal-dependent...
  10. doi request reprint About the background distribution in MR data: a local variance study
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid, Spain
    Magn Reson Imaging 28:739-52. 2010
    ..As an example, the model is used to study the effect of the background size over noise estimation techniques and a method to test the validity of background-based noise estimators is presented...
  11. ncbi request reprint On the estimation of the coefficient of variation for anisotropic diffusion speckle filtering
    Santiago Aja-Fernandez
    E T S Ingenieros de Telecomunicación, Universidad de Valladolid, 47011 Valladolid, Spain
    IEEE Trans Image Process 15:2694-701. 2006
    ..Then, we show that, as long as the estimates are good enough, the filter proposed here and the SRAD perform fairly closely, a fact that emphasizes the importance of the correct estimation of the coefficients of variation...
  12. doi request reprint Noise estimation in single- and multiple-coil magnetic resonance data based on statistical models
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid 47011, Spain
    Magn Reson Imaging 27:1397-409. 2009
    ....
  13. ncbi request reprint Image quality assessment based on local variance
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicación Valladolid Univ, Spain
    Conf Proc IEEE Eng Med Biol Soc 1:4815-8. 2006
    ..We show that this new index outperforms other methods for the assessment of image quality in medical images...
  14. pmc A new methodology for the estimation of fiber populations in the white matter of the brain with the Funk-Radon transform
    Antonio Tristan-Vega
    Laboratory of Image Processing, Universidad de Valladolid, Spain
    Neuroimage 49:1301-15. 2010
    ..Extensive experiments with both synthetic and real data have been intended to show that the new techniques improve existing ones in many situations...
  15. pmc Bias of least squares approaches for diffusion tensor estimation from array coils in DT-MRI
    Antonio Tristan-Vega
    Laboratory of Image Processing, Universidad de Valladolid, Spain
    Med Image Comput Comput Assist Interv 12:919-26. 2009
    ..Results show that the bias in the computation of the components of the DT may be comparable to their variance in many cases, stressing the importance of unbiased filtering previous to DT estimation...
  16. pmc Optimal real-time estimation in diffusion tensor imaging
    Pablo Casaseca-de-la-Higuera
    Laboratorio de Procesado de Imagen LPI, Universidad de Valladolid, Valladolid, Spain
    Magn Reson Imaging 30:506-17. 2012
    ..Results on both synthetic and real data show that our method outperforms those so far proposed, reaching the best performance of the existing proposals by processing a substantially lower number of diffusion images...
  17. doi request reprint Noise and signal estimation in magnitude MRI and Rician distributed images: a LMMSE approach
    Santiago Aja-Fernandez
    LPI, ETSI Telecomunicacion, Universidad de Valladolid, Valladolid, Spain
    IEEE Trans Image Process 17:1383-98. 2008
    ..This paper also includes the derivation of the probability density function of several local sample statistics for the Rayleigh and Rician model, upon which the estimators are built...
  18. doi request reprint A magnetic resonance software simulator for the evaluation of myocardial deformation estimation
    Lucilio Cordero-Grande
    Laboratorio de Procesado de Imagen, ETSIT, University of Valladolid, Paseo de Belén 15, 40011 Valladolid, Spain
    Med Eng Phys 35:1331-40. 2013
    ....
  19. pmc A generalized gamma mixture model for ultrasonic tissue characterization
    Gonzalo Vegas-Sanchez-Ferrero
    Laboratorio de Procesado de Imagen, ETSI Telecomunicación Edificio de las Nuevas Tecnologías, Campus Miguel Delibes s n, Universidad de Valladolid, 47011 Valladolid, Spain
    Comput Math Methods Med 2012:481923. 2012
    ..Results showed the better performance of the GG distribution in characterizing the speckle of blood and myocardial tissue in ultrasonic images...
  20. pmc Impact of MR Acquisition Parameters on DTI Scalar Indexes: A Tractography Based Approach
    Gonzalo Barrio-Arranz
    Laboratorio de Procesado de Imagen, Departamento de Teoría de la Señal y Comunicaciones e Ingeniería Telemática ETSI Telecomunicación, Universidad de Valladolid, Valladolid, Espana
    PLoS ONE 10:e0137905. 2015
    ..Even if the choice of a tractography algorithm has an effect on the numerical values of the final scalar measures, the evolution of these measures when acquisition parameters are modified is parallel. ..
  21. ncbi request reprint Group-Slicer: a collaborative extension of 3D-Slicer
    Federico Simmross-Wattenberg
    Laboratorio de Procesado de Imagen, ETSI Telecomunicacion, Universidad de Valladolid, 47011 Valladolid, Spain
    J Biomed Inform 38:431-42. 2005
    ..We show how this tool can be easily modified to make it collaborative so that it may constitute an integrated environment for expertise exchange as well as a useful tool for academic purposes...
  22. doi request reprint A 3-D collision handling algorithm for surgery simulation based on feedback fuzzy logic
    Verónica García-Pérez
    Laboratorio de Procesado de Imagen, Universidad de Valladolid, Valladolid 47002, Spain
    IEEE Trans Inf Technol Biomed 13:451-7. 2009
    ..Experimental results show that the solution proposed in this paper is able to avoid the interpenetration among the multiple colliding points efficiently with physically and spatially coherent results...
  23. doi request reprint DWI filtering using joint information for DTI and HARDI
    Antonio Tristan-Vega
    Laboratory of Image Processing, University of Valladolid, E T S Telecomunicaciones, 47011 Valladolid, Spain
    Med Image Anal 14:205-18. 2010
    ..Among the techniques presented, the joint LMMSE is proved a very attractive approach, since it shows an accuracy similar to UNLM (or even better in some situations) with a much lighter computational load...
  24. doi request reprint Estimation of fiber orientation probability density functions in high angular resolution diffusion imaging
    Antonio Tristan-Vega
    Laboratory of Image Processing, University of Valladolid, Spain
    Neuroimage 47:638-50. 2009
    ....
  25. pmc On the blurring of the Funk-Radon transform in Q-Ball imaging
    Antonio Tristan-Vega
    Laboratory of Image Processing, University of Valladolid, Spain
    Med Image Comput Comput Assist Interv 12:415-22. 2009
    ....
  26. ncbi request reprint Design and construction of a realistic DWI phantom for filtering performance assessment
    Antonio Tristan-Vega
    Laboratory of Image Processing, University of Valladolid, Spain
    Med Image Comput Comput Assist Interv 12:951-8. 2009
    ....
  27. doi request reprint A maximum likelihood approach to diffeomorphic speckle tracking for 3D strain estimation in echocardiography
    Ariel H Curiale
    Laboratorio de Procesado de Imagen LPI, E T S Ingenieros de Telecomunicación, Universidad de Valladolid, Valladolid, Spain Electronic address
    Med Image Anal 24:90-105. 2015
    ..These results indicate that the proposed diffeomorphic speckle tracking method provides robust and accurate motion and strain estimation...
  28. doi request reprint Influence of ultrasound speckle tracking strategies for motion and strain estimation
    Ariel H Curiale
    Consejo Nacional de Investigaciones Cientificas y Tecnicas, FCEN, Universidad Nacional de Cuyo, Padre Jorge Contreras 1300, 5500 Mendoza, Argentina Departamento de Física Médica, Centro Atomico Bariloche, Avenida Bustillo 9500, 8400 S C de Bariloche, RN, Argentina Fundación Escuela Medicina Nuclear, Garibaldi 405 5500, Mendoza, Argentina Laboratorio de Procesado de Imagen LPI, E T S Ingenieros de Telecomunicación, Universidad de Valladolid, Valladolid, Spain Electronic address
    Med Image Anal 32:184-200. 2016
    ..They can be further use to evaluate and design new strategy into a Speckle Tracking system. ..
  29. doi request reprint Attention deficit/hyperactivity disorder and medication with stimulants in young children: a DTI study
    Rodrigo de Luis-Garcia
    Laboratorio de Procesado de Imagen LPI, Universidad de Valladolid, Spain Electronic address
    Prog Neuropsychopharmacol Biol Psychiatry 57:176-84. 2015
    ..These findings may help elucidate the nature of white matter alterations in ADHD, their relationship with symptoms and the effects of treatment with psychostimulants...
  30. doi request reprint Fully automatic detection of salient features in 3-d transesophageal images
    Ariel H Curiale
    Laboratorio de Procesado de Imagen, ETS Ingenieros de Telecomunicación, Universidad de Valladolid, Valladolid, Spain Thoraxcenter Biomedical Engineering, Erasmus University Medical Center, Rotterdam, The Netherlands Electronic address
    Ultrasound Med Biol 40:2868-84. 2014
    ..01, 0.03); right atrium (-0.04, 0.13); and aorta (-0.05, 0.14). These results indicate that the proposed approach provides robust and accurate detection to initialize a multicavity segmentation approach without any user interaction. ..