Novel Method to Improve the Uniformity of 7T Body MR Images

Table 3

Mean and SD of 2D-|Mt| and unaveraged SAR within the human body model, Ella (Figures 5 and 6).

	Quad. driving	RF shimming (single mode)			RSMR Case I			RSMR Case II (η = 1.0)
		η = 1.0	0.5	0.0	η = 1.0	0.5	0.0
Mean |Mt| − 2D (A/m)	0.64	0.89 (39%)	0.87	0.69	0.94 (47%)	0.93	0.51	0.92 (44%)
SD |Mt| − 2D	0.31	0.19 (39%)	0.20	0.30	0.16 (48%)	0.17	0.32	0.17 (45%)
Max SAR − 2D (W/kg)	205	11.7 (94%)	10.2	6.32	12.3 (94%)	9.56	6.32	16.6 (92%)
Mean SAR − 2D (W/kg)	12.8	0.38 (97%)	0.35	0.32	0.38 (97%)	0.34	0.28	0.36 (97%)

Cost function: η×|M_t|-inhomogeneity +(1−η)×SAR-Max, Case I: (0–80) + (80–150) + (150–500 mm), Case II: (0–200) + (200–500 mm).