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Robust MRI brain tissue parameter estimation by multistage outlier rejection
Author(s) -
Manjón José V.,
Tohka Jussi,
GarcíaMartí Gracian,
CarbonellCaballero José,
Lull Juan J.,
MartíBonmatí Luís,
Robles Montserrat
Publication year - 2008
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.21521
Subject(s) - outlier , partial volume , voxel , computer science , brain tissue , pattern recognition (psychology) , artificial intelligence , data set , feature (linguistics) , magnetic resonance imaging , set (abstract data type) , neuroimaging , biomedical engineering , radiology , medicine , linguistics , programming language , psychiatry , philosophy
Abstract This article addresses the problem of the tissue type parameter estimation in brain MRI in the presence of partial volume effects. Automatic MRI brain tissue classification is hampered by partial volume effects that are caused by the finite resolution of the acquisition process. Due to this effect intensity distributions in brain MRI cannot be well modeled by a simple mixture of Gaussians and therefore more complex models have been developed. Unfortunately, these models do not seem to be robust enough for clinical conditions, as the quality of the tissue classification decreases rapidly with the image quality. Also, the application of these methods for pathological images with unmodeled intensities (e.g. MS plaques, tumors, etc.) remains uncertain. In the present work a new robust method for brain tissue characterization is presented, treating the partial volume affected voxels as outliers of the pure tissue distributions. The proposed method estimates the tissue characteristics from a reduced set of intensities belonging to a particular pure tissue class. This reduced set is selected by using a trimming procedure based on local gradient information and distributional data. This feature makes the method highly tolerant of a large amount of unexpected intensities without degrading its performance. The proposed method has been evaluated using both synthetic and real MR data and compared with state‐of‐the‐art methods showing the best results in the comparative. Magn Reson Med 59:866–873, 2008. © 2008 Wiley‐Liss, Inc.