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Advantage of sampling density weighted apodization over postacquisition filtering apodization for sodium MRI of the human brain
Author(s) -
Stobbe Robert,
Beaulieu Christian
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.21738
Subject(s) - apodization , sampling (signal processing) , noise (video) , projection (relational algebra) , filter (signal processing) , mathematics , optics , computer science , artificial intelligence , algorithm , image (mathematics) , computer vision , physics
For sodium imaging of the human brain, Gibbs' ringing can degrade image appearance and confound image analysis; k ‐space filtering is generally required. In this work, the signal to noise ratio (SNR) advantage of sampling density weighted apodization (SDWA) over uniform k ‐space sampling with postacquisition filtering apodization (UPFA) is quantified for sodium three‐dimensional (3D) twisted projection imaging (TPI) of the human brain. A direct comparison was conducted with the creation of two TPI projection data sets (each with an equal number of projections of equal length): one generating uniform sampling density, and the other a “generalized Hamming” sampling density that conformed to 3D‐TPI constraints for full k ‐space sampling. In this work it is shown theoretically, and then experimentally with sodium imaging of the human brain, that an SNR advantage of 17% is associated with the use of SDWA over UPFA for the filter presented, along with a significant noise‐coloring benefit. Magn Reson Med 60:981–986, 2008. © 2008 Wiley‐Liss, Inc.