Premium
T 1 corrected B 1 mapping using multi‐TR gradient echo sequences
Author(s) -
Voigt Tobias,
Nehrke Kay,
Doessel Olaf,
Katscher Ulrich
Publication year - 2010
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.22333
Subject(s) - flip angle , echo time , sequence (biology) , noise (video) , range (aeronautics) , algorithm , pulse sequence , pulse (music) , amplitude , reliability (semiconductor) , signal to noise ratio (imaging) , gradient echo , imaging phantom , computer science , nuclear magnetic resonance , physics , mathematics , materials science , optics , artificial intelligence , chemistry , image (mathematics) , magnetic resonance imaging , medicine , biochemistry , power (physics) , composite material , quantum mechanics , detector , radiology
This work presents a new approach toward a fast, simultaneous amplitude of radiofrequency field ( B 1 ) and T 1 mapping technique. The new method is based on the “actual flip angle imaging” (AFI) sequence. However, the single pulse repetition time (TR) pair used in the standard AFI sequence is replaced by multiple pulse repetition time sets. The resulting method was called “multiple TR B 1 / T 1 mapping” (MTM). In this study, MTM was investigated and compared to standard AFI in simulations and experiments. Feasibility and reliability of MTM were proven in phantom and in vivo experiments. Error propagation theory was applied to identify optimal sequence parameters and to facilitate a systematic noise comparison to standard AFI. In terms of accuracy and signal‐to‐noise ratio, the presented method outperforms standard AFI B 1 mapping over a wide range of T 1 . Finally, the capability of MTM to determine T 1 was analyzed qualitatively and quantitatively, yielding good agreement with reference measurements. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.