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On the nature and reduction of the displacement artifact in flow images
Author(s) -
Nishimura Dwight G.,
Jackson John I.,
Pauly John M.
Publication year - 1991
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.1910220255
Subject(s) - artifact (error) , offset (computer science) , encoding (memory) , projection (relational algebra) , displacement (psychology) , computer science , flow (mathematics) , reduction (mathematics) , artificial intelligence , computer vision , algorithm , mathematics , geometry , psychology , psychotherapist , programming language
In flow‐imaging experiments with 2‐D Fourier transform sequences, the time difference between phase encoding and readout leads to a potentially misleading displacement artifact. This artifact arises in regions of rapid flow and high shear, and manifests as an intensity distortiion in additton to a bulk shift. We have studied methods of mitigating the artifact, including offset‐echo acquisition, backward‐evolving phase encoding, moment‐compensated phase encoding, and projection‐reconstruction imaging. Experiments on flow phantoms verified the nature and reduction of this displacement artifact. Of the four methods studied, the projection‐reconstruction sequence proved to be the most effective, completely eliminating the artifact. © 1991 Academic Press, Inc.