Improved Volume Localization for MRSI at 7T Using RF Shimming and RF Multiplexing

Hoby P. Hetherington¹, Nikolai I. Avdievich¹, Jullie Pan¹

At 7T, increased spectral dispersion and decreased B1 results in increased spectral dispersion artifacts when using slice or slab selective pulses. Recent developments of RF shimming based localization using ring distributions generated solely by RF shimming eliminate spectral dispersion artifacts. However, with only 8 independent RF coils/RF channels, the ring distribution can reduce SNR for the neocortical periphery. In this work we describe an improved RF shimming based localization method using a 16 coil transceiver array and RF multiplexing to dramatically improve the selectivity of the ring distribution and preserve SNR for MRSI in the cortical periphery.