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POCS‐enhanced inherent correction of motion‐induced phase errors (POCS‐ICE) for high‐resolution multishot diffusion MRI
Author(s) -
Guo Hua,
Ma Xiaodong,
Zhang Zhe,
Zhang Bida,
Yuan Chun,
Huang Feng
Publication year - 2016
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.25594
Subject(s) - computer science , computer vision , artificial intelligence , phase (matter) , diffusion mri , motion (physics) , convergence (economics) , image quality , diffusion , trajectory , image (mathematics) , algorithm , physics , magnetic resonance imaging , radiology , medicine , quantum mechanics , economics , economic growth , thermodynamics , astronomy
Purpose For multishot diffusion weighted imaging (DWI), one of the challenges is to remove phase variations induced by physiological motion among different shots. In this study, a new method is proposed to iteratively solve the phase errors and DWI images simultaneously, for navigator‐free acquisitions. Theory and Methods Instead of solving phase errors and the image sequentially in the two‐step parallel imaging, the proposed method, named POCS‐enhanced Inherent Correction of motion‐induced phase Errors (POCS‐ICE), treats both the phase and DWI image as unknowns and solves them simultaneously. Multishot DWI with constant density spiral trajectory served as a specific example. Simulation and in vivo experiments were performed to evaluate the proposed method. Results POCS‐ICE shows improved image quality in terms of higher SNR and fewer artifacts than the compared method, SENSE+CG. The improvement becomes more conspicuous as the number of shots increases. The convergence behavior of POCS‐ICE was also shown to be more stable. Conclusion POCS‐ICE can inherently and reliably correct motion‐induced phase errors in navigator‐free multishot DWI, and it is easier to determine the stopping criterion without manual interventions. The improved spatial resolution and image resolvability are beneficial to study of brain microstructures and physiological features for neuroscience. Magn Reson Med 75:169–180, 2016. © 2015 Wiley Periodicals, Inc.