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 %.