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Rapid multicomponent relaxometry in steady state with correction of magnetization transfer effects
Author(s) -
Liu Fang,
Block Walter F.,
Kijowski Richard,
Samsonov Alexey
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.25672
Subject(s) - relaxometry , magnetization transfer , macromolecule , proton , chemistry , steady state (chemistry) , biological system , transferability , nuclear magnetic resonance , magnetization , magnetic resonance imaging , computer science , physics , radiology , spin echo , medicine , machine learning , biochemistry , biology , quantum mechanics , logit , magnetic field
Purpose To study the effects of magnetization transfer (MT) on multicomponent T 2 parameters obtained using mcDESPOT in macromolecule‐rich tissues and to propose a new method called mcRISE to correct MT‐induced biases. Methods The two‐pool mcDESPOT model was modified by the addition of an exchanging macromolecule proton pool to model the MT effect in cartilage. The mcRISE acquisition scheme was developed to provide sensitivity to all pools. An incremental fitting was applied to estimate MT and relaxometry parameters with minimized coupling. The interaction between MT and relaxometry parameters, efficacy of MT correction, and feasibility of mcRISE in vivo were investigated in simulations and in healthy volunteers. Results The MT effect caused significant errors in multicomponent T 1 /T 2 values and in fast‐relaxing water fraction f F , which is consistent with previous experimental observations. f F increased significantly with macromolecule content if MT was ignored. mcRISE resulted in a multifold reduction of MT biases and yielded decoupled multicomponent T 1 /T 2 relaxometry and quantitative MT parameters. Conclusion mcRISE is an efficient approach for correcting MT biases in multicomponent relaxometry based on steady state sequences. Improved specificity of mcRISE may help to elucidate the sources of the previously described high sensitivity of noncorrected mcDESPOT parameters to disease‐related changes in cartilage and the brain. Magn Reson Med 75:1423–1433, 2016. © 2015 Wiley Periodicals, Inc.