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Fast T 2 relaxometry with an accelerated multi‐echo spin‐echo sequence
Author(s) -
Sénégas Julien,
Liu Wei,
Dahnke Hannes,
Song Hotaek,
Jordan E. Kay,
Frank Joseph A.
Publication year - 2010
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.1521
Subject(s) - acceleration , computer science , echo (communications protocol) , spin echo , compressed sensing , undersampling , nuclear magnetic resonance , sampling (signal processing) , iterative reconstruction , algorithm , artificial intelligence , signal (programming language) , physics , pattern recognition (psychology) , magnetic resonance imaging , computer vision , medicine , computer network , filter (signal processing) , classical mechanics , radiology , programming language
A new method has been developed to reduce the number of phase‐encoding steps in a multi‐echo spin‐echo imaging sequence allowing fast T 2 mapping without loss of spatial resolution. In the proposed approach, the k ‐space data at each echo time were undersampled and a reconstruction algorithm that exploited the temporal correlation of the MR signal in k ‐space was used to reconstruct alias‐free images. A specific application of this algorithm with multiple‐receiver acquisition, offering an alternative to existing parallel imaging methods, has also been introduced. The fast T 2 mapping method has been validated in human brain T 2 measurements in a group of nine volunteers with acceleration factors up to 3.4. The results demonstrated that the proposed method exhibited excellent linear correlation with the regular T 2 mapping with full sampling and achieved better image reconstruction and T 2 mapping with respect to SNR and reconstruction artifacts than the selected reference acceleration techniques. The new method has also been applied for quantitative tracking of injected magnetically labeled breast cancer cells in the rat brain with acceleration factors of 1.8 and 3.0. The proposed technique can provide an effective approach for accelerated T 2 quantification, especially for experiments with single‐channel coil when parallel imaging is not applicable. Copyright © 2010 John Wiley & Sons, Ltd.