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An iterative spherical mean value method for background field removal in MRI
Author(s) -
Wen Yan,
Zhou Dong,
Liu Tian,
Spincemaille Pascal,
Wang Yi
Publication year - 2014
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.24998
Subject(s) - imaging phantom , artifact (error) , truncation (statistics) , radius , deconvolution , field (mathematics) , spherical mean , computer science , algorithm , reduction (mathematics) , spherical harmonics , mathematics , physics , artificial intelligence , optics , statistics , mathematical analysis , geometry , computer security , pure mathematics
Purpose The sophisticated harmonic artifact reduction for phase data (SHARP) method has been proposed for the removal of background field in MRI phase data. It relies on the spherical mean value (SMV) property of harmonic functions, and its accuracy depends on the radius of the sphere used for computing the SMV and truncation threshold needed for deconvolution. The goal of this study was to develop an alternative SMV‐based background field removal method with reduced dependences on these parameters. Methods The proposed background field removal method, termed iterative SMV (iSMV), consists of applying the SMV operation repeatedly on the field map. It was validated in a phantom and in vivo brain data of five healthy volunteers. Results The iSMV method demonstrates accurate background field removal in the phantom. Compared with SHARP, the iSMV method shows a significantly reduced dependence on the SMV radius both in phantom and in human data. Because a smaller radius can be chosen, the iSMV method allows retaining a larger part of the region of interest compared with SHARP. Conclusion The iSMV method is an effective background field removal method with a reduced dependence on method parameters. Magn Reson Med 72:1065–1071, 2014. © 2013 Wiley Periodicals, Inc.