Premium
Application of k ‐space energy spectrum analysis for inherent and dynamic B 0 mapping and deblurring in spiral imaging
Author(s) -
Truong TrongKha,
Chen Nankuei,
Song Allen W.
Publication year - 2010
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.22485
Subject(s) - deblurring , spiral (railway) , computer science , dynamic imaging , k space , amplitude , energy (signal processing) , residual , algorithm , noise (video) , artificial intelligence , temporal resolution , computer vision , physics , image processing , image (mathematics) , mathematics , image restoration , optics , mathematical analysis , quantum mechanics , digital image processing , fourier transform
Abstract Spiral imaging is vulnerable to spatial and temporal variations of the amplitude of the static magnetic field ( B 0 ) caused by susceptibility effects, eddy currents, chemical shifts, subject motion, physiological noise, and system instabilities, resulting in image blurring. Here, a novel off‐resonance correction method is proposed to address these issues. A k ‐space energy spectrum analysis algorithm is first applied to inherently and dynamically generate a B 0 map from the k ‐space data at each time point, without requiring any additional data acquisition, pulse sequence modification, or phase unwrapping. A simulated phase evolution rewinding algorithm and an automatic residual deblurring algorithm are then used to correct for the blurring caused by both spatial and temporal B 0 variations, resulting in a high spatial and temporal fidelity. This method is validated against conventional B 0 mapping and deblurring methods, and its advantages for dynamic MRI applications are demonstrated in functional MRI studies. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.