Volume array coil with enforced uniform element currents for improved excitation homogeneity

Abstract

Each of the coils in a transmit coil array of a magnetic resonance imaging apparatus is electrically connected to a common voltage point by a transmission line. By controlling the electrical length of the transmission line connecting each of the coils to the common voltage point to an odd integer multiple of one quarter wavelength, the current delivered to each coil is independent of coil impedance. This principle of forced current excitation enables equal currents to be delivered to each coil of a magnetic resonance imaging transmit coil array regardless of the unique loading of the individual coils and mutual impedance between the coils.