Blipped multi gradient-echo slice excitation profile imaging (bmGESEPI) for fast T2 * measurements with macroscopic B0 inhomogeneity compensation.
With the rapid development of human MRI at field strengths > or = 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 > or = 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.
Truong
Trong-Kha
TK
Department of Radiology, The Ohio State University, Columbus, 43210, USA.
Chakeres
Donald W
DW
Scharre
Douglas W
DW
Beversdorf
David Q
DQ
Schmalbrock
Petra
P