Simulation results for sensitivity of the proposed approach to high-frequency oscillating magnetic field.
a: Effects of the number of dynamic scans (200, 500, and 1000). Oscillating magnetic fields ΔB(t) with strength and frequency of 1nT and 25 Hz were used. Frequency range of the spectra was adjusted to the sampling period of 10 ms, which was derived from TR of 10 ms and the target frequency of 25 Hz. Mean SNR spectra were derived by ROI averaging. b: Comparison of constant (left) and random ON/OFF (right) oscillating magnetic fields with a frequency of 25 Hz. In random ON/OFF oscillation, ΔB(t) was alternatingly turned on and off and the off-state was about 36% of the total states.