Analytical Examination on Asymmetric Distributions of Transmission and Reception RF Fields by a Quadrature Coil at High Magnetic Field

Hidehiro Watanabe¹

Maps of the transmission field B_1t⁺ and the reception filed B_1r^- by a quadrature coil differ and show mirror symmetry in human brain at high field. This is similar to a feature in a linear coil. We analytically examined the source of this mirror symmetry in a quadrature coil. We found that B_1t⁺ and B_1r^- differ in the sign of the sinusoidal phase difference. This relationship is similar to that in a linear coil. We also examined maps of magnitude and phase components in the laboratory frame computed from B_1t⁺ and B_1r^- maps of human brains at 4.7 T.