Editing Magnetic Resonance Spectroscopy of Lactate at High Fields: Improved Efficiency by Inclusion of FOCI Pulses and Elimination of Co-Edited Macromolecules

Jannie P. Wijnen¹, Catalina S. Arteaga de Castro¹, Vincent Oltman Boer², Anna Andreychenko¹, Peter R. Luijten¹, Bas Neggers³, Dennis W.J. Klomp¹

The weakly coupled spin system of low concentrated lactate can be measured with MRS editing techniques. Obtaining this at the potentially high sensitivity of high field strength can be challenging due to the low available B1+ field resulting in narrow bandwidth refocusing pulses and therefore in large chemical shift displacement errors (CSDE). Frequency offset corrected inversion (FOCI) pulses substantially increase the bandwidth of adiabatic pulses and are used in this study in a MEGA-sLASER editing sequence for highly efficient measurements of lactate. Combined with nulling of co-edited macromolecules, we demonstrate that artefact free lactate signals can be detected in the human brain at 7T.