Fig. 3
i B0 field homogeneity across the nine phantom compartments as a measure of off-resonance in Hertz (Hz) at 1.5 T (blue) and 3 T (green) are shown (bottom). The associated B0 field maps with the field of view capturing the whole phantom at 1.5 T and 3 T are also presented (top–tube positions are overlaid in red). ii) B1 field homogeneity across the nine phantom compartments as a measure of the FA (in degrees) at 1.5 T (red) and 3 T (blue) are shown (bottom). These represent small shifts in FA or frequency (e.g.,10 Hz = 0.08 ppm at 3 T) and should not be regarded as significantly different between the tube compartments. As expected, the variation of relative FA is larger at 3 T (0.590–0.656) compared to 1.5 T (0.849–0.866). The associated B1 field maps of at 1.5 T and 3 T are also presented (top–tube positions are overlaid in red). FA flip angle. Other abbreviations as in Fig. 2