RF shimming can increase B1+ availability, which is critical for robust localised MR spectroscopy at ultra-high field. Shim calibration is performed on a region-wise basis and is, therefore, time consuming. Additionally, B1 distributions become difficult to predict. Recent work has shown that ‘universal’ pulses can be generated offline – avoiding the need for calibration. Here, we determine static calibration-free RF shims, optimised over 5 heads, for 3 different brain regions. B1+ availability using calibration-free shims was significantly higher than quadrature and comparable to tailored shimming. High quality spectra were also obtained from 3 regions with the calibration-free shims.
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