FIGURE 6.

Effect of fetal rotation by 20° (BCH4-2-2), 160° (BCH4-2-3), and 180° (BCH4-2-4) inside the uterus on maternal and fetal peak local SAR (pSAR10g), fetal average SAR (aveSAR), average $\left|{\text{B}}_1^{+}\right|$ and $\left|{\text{B}}_1^{+}\right|$ coefficients of variation (CV) for body model BCH4-2-1. Worst-case: RF shim setting that maximizes an individual SAR metric, CP mode: circularly polarized birdcage mode, RFS: RF shim settings that improve imaging performance in any of the four models BCH4-2-1, BCH4-2-2, BCH4-2-3, and BCH4-2-4