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Pseudo‐gating: Elimination of periodic motion artifacts in magnetic resonance imaging without gating
Author(s) -
Haacke E. Mark,
Lenz Gerald W.,
Nelson A. Dennis
Publication year - 1987
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.1910040209
Subject(s) - gating , multislice , signal (programming language) , motion (physics) , computer science , noise (video) , echo (communications protocol) , nuclear magnetic resonance , magnetic resonance imaging , periodic function , artifact (error) , encoding (memory) , computer vision , artificial intelligence , physics , mathematics , medicine , mathematical analysis , image (mathematics) , physiology , computer network , radiology , programming language
This note explains and illustrates a technique of reducing artifacts produced by periodic motion without using physiologic gating. The method is simple and can be applied on any standard MRI unit. For periodic motion, effective gating can be attained by setting the product of the number of acquisitions (at each phase‐encoding step), N , times the repeat time, T R , equal to the period of the motion, T . This pseudo‐gating can be used with any T R but, if changes in the period occur, is most robust with short T R values. The method is also applicable to multislice and volume imaging. For fast field echo methods, the above rule can be used if the period of the motion is smaller than the total scan time. Otherwise, the scan need only be repeated N times to avoid artifacts and improve signal‐to‐noise. The method has been implemented to remove both respiratory and/or cardiac motion artifacts. © 1987 Academic Press, Inc.