Estimating the apparent transverse relaxation time (R2(*)) from images with different contrasts (ESTATICS) reduces motion artifacts.

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Version: Final published version
Serval ID
serval:BIB_C299D50F5C16
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Estimating the apparent transverse relaxation time (R2(*)) from images with different contrasts (ESTATICS) reduces motion artifacts.
Journal
Frontiers in Neuroscience
Author(s)
Weiskopf N., Callaghan M.F., Josephs O., Lutti A., Mohammadi S.
ISSN
1662-4548 (Print)
ISSN-L
1662-453X
Publication state
Published
Issued date
2014
Peer-reviewed
Oui
Volume
8
Pages
278
Language
english
Notes
Publication types: Journal Article Publication Status: epublish
Abstract
Relaxation rates provide important information about tissue microstructure. Multi-parameter mapping (MPM) estimates multiple relaxation parameters from multi-echo FLASH acquisitions with different basic contrasts, i.e., proton density (PD), T1 or magnetization transfer (MT) weighting. Motion can particularly affect maps of the apparent transverse relaxation rate R2(*), which are derived from the signal of PD-weighted images acquired at different echo times. To address the motion artifacts, we introduce ESTATICS, which robustly estimates R2(*) from images even when acquired with different basic contrasts. ESTATICS extends the fitted signal model to account for inherent contrast differences in the PDw, T1w and MTw images. The fit was implemented as a conventional ordinary least squares optimization and as a robust fit with a small or large confidence interval. These three different implementations of ESTATICS were tested on data affected by severe motion artifacts and data with no prominent motion artifacts as determined by visual assessment or fast optical motion tracking. ESTATICS improved the quality of the R2(*) maps and reduced the coefficient of variation for both types of data-with average reductions of 30% when severe motion artifacts were present. ESTATICS can be applied to any protocol comprised of multiple 2D/3D multi-echo FLASH acquisitions as used in the general research and clinical setting.
Pubmed
Web of science
Open Access
Yes
Create date
17/01/2015 11:09
Last modification date
20/08/2019 15:37
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