Ulrike Dydak1,2,
Malgorzata Marjanska3, Stefan Posse4,5
1School of Health Sciences, Purdue
University, West Lafayette, IN, United States; 2Department of
Radiology and Imaging Sciences, Indiana University School of Medicine,
Indianapolis, IN, United States; 3Center for Magnetic Resonance
Research and Department of Radiology, University of Minnesota, Minneapolis,
MN, United States; 4Department of Neurology, University of New
Mexico School of Medicine, Albuquerque, NM, United States; 5Department
of Electrical and Computer Engineering, University of New Mexico, Albuquerque,
NM, United States
The
feasibility of GABA-edited magnetic resonance spectroscopic imaging with
short scan times is demonstrated both in a phantom and in vivo by combining
the high-speed (Proton-Echo-Planar-Spectroscopic-Imaging) PEPSI sequence with
the MEGA editing scheme. We show MEGA-PEPSI spectra from an axial slice in
the human brain acquired at 3 T within < 5 min with a nominal resolution
of 8 ml. The signal of GABA and co-edited macromolecules is clearly
discernable in most spectra and was fitted with LCModel, using a simulated
basis for this sequence. Spectral fitting of the GABA resonance was feasible
with Cramer Rao lower bounds < 20 %.
Keywords