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Motion‐insensitive susceptibility weighted imaging
Author(s) -
Berglund Johan,
Sprenger Tim,
Niekerk Adam,
Rydén Henric,
Avventi Enrico,
Norbeck Ola,
Skare Stefan
Publication year - 2021
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.28850
Subject(s) - snapshot (computer storage) , image quality , computer vision , artificial intelligence , computer science , scanner , image (mathematics) , operating system
Purpose To enable SWI that is robust to severe head movement. Methods Prospective motion correction using a markerless optical tracker was applied to all pulse sequences. Three‐dimensional gradient‐echo and 3D EPI were used as reference sequences, but were expected to be sensitive to motion‐induced B 0 changes, as the long TE required for SWI allows phase discrepancies to accumulate between shots. Therefore, 2D interleaved snapshot EPI was investigated for motion‐robust SWI and compared with conventional 2D EPI. Repeated signal averages were retrospectively corrected for motion. The sequences were evaluated at 3 T through controlled motion experiments involving two cooperative volunteers and SWI of a tumor patient. Results The performed continuous head motion was in the range of 5–8° rotations. The image quality of the 3D sequences and conventional 2D EPI was poor unless the rotational motion axis was parallel to B 0 . Interleaved snapshot EPI had minimal intraslice phase discrepancies due to its small temporal footprint. Phase inconsistency between signal averages was well tolerated due to the high‐pass filter effect of the SWI processing. Interleaved snapshot EPI with prospective and retrospective motion correction demonstrated similar image quality, regardless of whether motion was present. Lesion depiction was equal to 3D EPI with matching resolution. Conclusion Susceptibility‐based imaging can be severely corrupted by head movement despite accurate prospective motion correction. Interleaved snapshot EPI is a superior alternative for patients who are prone to move and offers SWI which is insensitive to motion when combined with prospective and retrospective motion correction.