Short TE Whole Brain MRSI with High-Bandwidth Adiabatic SLR Refocusing and Echo Planar Readout

Meng Gu¹, Priti Balchandani¹, ², Sulaiman Sheriff³, Mohammad Sabati³, Daniel Spielman¹, Andrew Maudsley³

MR spectroscopic imaging with localization schemes using conventional RF pulses suffer from B1 inhomogeneity and chemical shift localization error due to bandwidth limitations. Adiabatic refocusing RF pulses have been introduced to overcome the B1 inhomogeneity. However, conventional hyperbolic secant adiabatic refocusing pulses are limited by long pulse-width, prohibiting acquisition with short TE. Here, we present a localization scheme using adiabatic SLR refocusing pulses with broad bandwidth and short pulse-width. This localization scheme was incorporated into a volumetric MRSI sequence with echo planar readout. In vivo study showed high quality spectra and metabolite maps were obtained throughout the brain.