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Motion artifact reduction in pediatric diffusion tensor imaging using fast prospective correction
Author(s) -
Alhamud A.,
Taylor Paul A.,
Laughton Barbara,
van der Kouwe André J.W.,
Meintjes Ernesta M.
Publication year - 2015
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.24678
Subject(s) - artifact (error) , diffusion mri , reduction (mathematics) , motion (physics) , diffusion , radiology , medicine , computer science , computer vision , magnetic resonance imaging , physics , mathematics , geometry , thermodynamics
Purpose To evaluate the patterns of head motion in scans of young children and to examine the influence of corrective techniques, both qualitatively and quantitatively. We investigate changes that both retrospective (with and without diffusion table reorientation) and prospective (implemented with a short navigator sequence) motion correction induce in the resulting diffusion tensor measures. Materials and Methods Eighteen pediatric subjects (aged 5–6 years) were scanned using 1) a twice‐refocused, 2D diffusion pulse sequence, 2) a prospectively motion‐corrected, navigated diffusion sequence with reacquisition of a maximum of five corrupted diffusion volumes, and 3) a T 1 ‐weighted structural image. Mean fractional anisotropy (FA) values in white and gray matter regions, as well as tractography in the brainstem and projection fibers, were evaluated to assess differences arising from retrospective (via FLIRT in FSL) and prospective motion correction. In addition to human scans, a stationary phantom was also used for further evaluation. Results In several white and gray matter regions retrospective correction led to significantly ( P < 0.05) reduced FA means and altered distributions compared to the navigated sequence. Spurious tractographic changes in the retrospectively corrected data were also observed in subject data, as well as in phantom and simulated data. Conclusion Due to the heterogeneity of brain structures and the comparatively low resolution (∼2 mm) of diffusion data using 2D single shot sequencing, retrospective motion correction is susceptible to distortion from partial voluming. These changes often negatively bias diffusion tensor imaging parameters. Prospective motion correction was shown to produce smaller changes. J. Magn. Reson. Imaging 2014. © 2014 Wiley Periodicals, Inc. J. Magn. Reson. Imaging 2015;41:1353–1364. © 2014 Wiley Periodicals, Inc.