Fig. 1

a. 6 pulse train numerically optimized for 3 T (\( {\widehat{B}}_1 \) = 0.4–1.2, B₀ = ±240 Hz, B₁ field = 14 μT), with a total duration of 32.8 ms. Gradient areas are the effective areas across all three gradient directions. b. 4 pulse train numerically optimized for 1.5 T (\( {\widehat{B}}_1 \) = 0.7–1.0, B₀ = ±120 Hz, B₁ field = 26.9 μT), with a total duration of 23.6 ms. The first four spoilers are the same for the 4 and 6 pulse trains and the last spoilers have the same pattern, but with the polarity in the slice select axis reversed to maintain alternating polarity. c. The optimized BIR4-90 pulse, with a total duration of 12.2 ms. All saturation pulses are shown on the same time, RF amplitude and gradient strength scale