Figure 4:
Simulated versus measured dependency of MP-FLAIR image intensity to B₁⁺. Dots: Measured MP-FLAIR intensities as a function of measured DREAM B1+. Colors depict different RF gains. Other sources of signal loss (e.g. B₁^-/B₀, fluid-content) cause the measured intensities to “fill out” the area under the curve. Black line: Simulated FLAIR intensities. Increasing discrepancy between simulation and measurements is seen below 60% and above 140% of B₁⁺, which is ascribed to inherent bias in the measured B₁⁺. Red line: The MP-FLAIR dependency to B₁⁺ used for bias-field correction.

Figure 3:
5 repetitions of an MP-FLAIR scan with different RF gains (0.6 – 1.4). For low RF gains, only the mid brain (where B₁⁺ is relatively large) experience close to nominal flip-angles. For RF gains higher than 0.8, the mid brain shows as hypo-intense due to flip-angles being larger than the nominal flip-angle. The lower occipital lobe (where B₁⁺ is relatively small), show as hypo-intense for all but the highest RF gain, where it experiences close to nominal flip angles and shows as hyper-intense, due to the surrounding tissue experiencing higher than nominal flip-angles.