FIG. 2.
Monte Carlo simulation of effect of off-resonance on the phase-sensitive method. The left panels (a) show the effect of off-resonance on the mean bias and standard deviation of the phase-sensitive flip angle estimate when B0 correction is performed, as described in Ref. 14. The right panels (b) show the effect of off-resonance if no B0 correction is performed. Off-resonance phase accrual during the RF excitation causes mean bias, but has little effect on the standard deviation of the estimate for the values of off-resonance precession of 7° and 14° shown. Note that these values were informed by the in vivo study shown in Fig. 5, where the maximum off-resonance precession angle across the breast was measured to be about 7°.