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Respiration artifact correction in three‐dimensional proton resonance frequency MR thermometry using phase navigators
Author(s) -
Svedin Bryant T.,
Payne Allison,
Parker Dennis L.
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.25860
Subject(s) - artifact (error) , nuclear magnetic resonance , phase (matter) , materials science , magnetic resonance imaging , free induction decay , respiration , nuclear medicine , standard deviation , echo (communications protocol) , biomedical engineering , physics , computer science , spin echo , medicine , mathematics , radiology , artificial intelligence , statistics , anatomy , quantum mechanics , computer network
Purpose To develop reliable three‐dimensional (3D) segmented echo planar imaging (seg‐EPI) proton resonance frequency (PRF) temperature monitoring in the presence of respiration‐induced B 0 variation. Methods A free induction decay (FID) phase navigator was inserted into a 3D seg‐EPI sequence before and after EPI readout to monitor B 0 field variations. Using the field change estimates, the phase of each k‐space line was adjusted to remove the additional phase from the respiratory induced off‐resonance. This correction technique was evaluated while heating with MR‐guided focused ultrasound (MRgFUS) in phantoms with simulated breathing and during nonheating conditions in healthy in vivo breasts. Results With k‐space phase correction, the standard deviation of magnitude images and PRF temperature measurements in breast from five volunteers improved by an average factor of 1.5 and 2.1, respectively. Improved accuracy of temperature estimates was observed after correction while heating with MRgFUS in phantoms. Conclusion Phase correction based on two FID navigators placed before and after the echo train provides promising results for implementing 3D monitoring of thermal therapy treatments in the presence of field variations due to respiration. Magn Reson Med 76:206–213, 2016. © 2015 Wiley Periodicals, Inc.