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Rapid and robust variable flip angle T 1 mapping using interleaved two‐dimensional multislice spoiled gradient echo imaging
Author(s) -
Heule Rahel,
Bieri Oliver
Publication year - 2017
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.26246
Subject(s) - flip angle , echo (communications protocol) , multislice , gradient echo , nuclear magnetic resonance , physics , variable (mathematics) , echo planar imaging , spin echo , magnetic resonance imaging , materials science , computer science , medicine , mathematics , radiology , computer network , mathematical analysis
Purpose Conventional T 1 mapping using three‐dimensional (3D) radiofrequency (RF) spoiled gradient echo (SPGR) imaging with short repetition times (TR) is adversely affected by incomplete spoiling (i.e. residual T 2 dependency). In this work, an optimized interleaved 2D multislice SPGR sequence scheme and an adapted postprocessing procedure are evaluated for highly T 2 ‐insensitive T 1 quantification of human brain tissues. Methods An efficient 2D multislice SPGR protocol including a relatively long TR of 200 ms is investigated with careful consideration of cross talk and magnetization transfer effects. Based on the derived scan protocol, T 1 is quantified from the signal ratio of two SPGR datasets acquired at different flip angles. The effect of nonideal RF excitation profiles is incorporated into the SPGR signal model by performing Bloch simulations. Results Simulations showed that the parameters of the SPGR protocol (such as TR and the spoiler gradient moments) guarantee virtually complete spoiling. This result was confirmed by T 1 measurements both in vitro using a 2% agar probe doped with 0.1 mM Gd (Gadovist) and in vivo in the human brain. Conclusion The derived 2D multislice SPGR protocol offers efficient, highly reproducible, and in particular T 2 ‐insensitive T 1 quantification of human brain tissues. Magn Reson Med 77:1606–1611, 2017. © 2016 International Society for Magnetic Resonance in Medicine