Cryogenic RF coil versus higher magnetic field strength for 1H fast FID-MRSI in the rat brain

Motivation: MRSI in small rodents is challenging due to inherent low sensitivity. This could be alleviated by higher magnetic field strengths or cryogenic RF coils. Goal(s): Compare 1H FID-MRSI in the rat brain between 9.4T with a cryogenic coil and 14.1T with a room-temperature coil. Approach: The quality of metabolic maps obtained from both setups was compared Results: Overall, both setups achieve metabolic quantification and mapping of similar qualities. The 9.4T setup provides better spatial coverage, higher SNR and more homogeneous B0, while the 14.1T benefits from better spectral resolution. Impact: High quality metabolite quantification and mapping with fast 1H FID-MRSI is achieved in the rat brain benefiting from either the unmatched sensitivity of cryogenic coils at 9.4T, or enhanced spectral resolution at 14.1T.