Single-Shot Interleaved Gradient Compensation of Susceptibility Induced Spectral Line Broadening in Proton Spectroscopic Echo-Planar Imaging (PEPSI)
Caprihan A, Li T, Posse S
New Mexico Resonance, The MIND Institute
We present a novel, single-shot spectroscopic imaging method that compensates local gradients in regions that suffer from susceptibility related spectral line broadening. The method was integrated into a PEPSI sequence and uses a train of alternating gradient pulses of increasing strengths, interleaved into the spatial-spectral encoding scheme, to simultaneously collect an uncompensated and a compensated data set. Controlled spectral aliasing was used to overcome gradient slew rate and stimulation limitations. Metabolite maps show strongly reduced susceptibility effects in frontal lobe in human brain at 4 Tesla.