Table 2.

Summary of the MRI performance of the RF applicators using the objective of maximization of minimum B₁⁺ (Equation (2)), minimization of the coefficient of variation (CoV, Equation (3)), and maximization of mean B₁⁺ across the brain of the human head voxel model Duke. Green and red numbers highlight the results obtained for each optimization goal outlined in the very left column. Gray numbers review results obtained outside of the optimization goal outlined in the very left column.

Optimization Goal	pTx Shimming Method	Min B1+ (µT/√kW)		Coefficient of Variation		Mean B1+ (µT/√kW)
		Helmet Array	Annular Array	Helmet Array	Annular Array	Helmet Array	Annular Array
Max (min B1+)	PS	2.12	2.04	0.98	1.41	8.82	9.89
	APS	2.71	1.75	2.87	1.62	8.78	10.81
min (CoV)	PS	0.06	0.48	0.96	0.97	8.10	11.01
	APS	0.02	1.62	0.51	0.88	3.68	11.47
Max (Mean B1+)	PS	0.047	0.087	0.95	1.12	10.6	13.61
	APS	0.34	0.01	1.33	1.99	11.1	13.71