Premium
Blipped multi gradient‐echo slice excitation profile imaging (bmGESEPI) for fast T 2 * measurements with macroscopic B 0 inhomogeneity compensation
Author(s) -
Truong TrongKha,
Chakeres Donald W.,
Scharre Douglas W.,
Beversdorf David Q.,
Schmalbrock Petra
Publication year - 2006
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.20916
Subject(s) - excitation , wafer , field (mathematics) , nuclear magnetic resonance , relaxation (psychology) , gradient echo , physics , field strength , compensation (psychology) , magnetic field , materials science , computer science , optics , magnetic resonance imaging , mathematics , optoelectronics , pure mathematics , radiology , medicine , psychology , social psychology , quantum mechanics , psychoanalysis
With the rapid development of human MRI at field strengths ≥ 7 T, knowledge of T 2 *relaxation times at such field strengths is needed to optimize acquisition parameters and understand relaxation mechanisms in many applications. However, standard T 2 *measurements (e.g., using conventional multiecho gradient‐echo (GE) sequences) are affected by macroscopic static magnetic field ( B 0 ) inhomogeneities, which are particularly severe at high field strength. The multi‐GE slice excitation profile imaging (mGESEPI) method was developed for T 2 *measurements in the presence of macroscopic B 0 inhomogeneity, but it requires excessive acquisition times at field strengths ≥ 7 T. In this paper a more efficient technique, named blipped mGESEPI (bmGESEPI), is proposed. To demonstrate its advantages, T 2 *maps were acquired using a conventional multiecho GE method, the mGESEPI method, and the bmGESEPI method in postmortem and in vivo human brains at 8 T. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.