A comparison study of regularization techniques on the theoretical design of phased array RF coils in MRI

In MRI engineering, regularization techniques can be effectively used to solve ill-posed problems in electromagnetics, such as the inverse design of phased array RF coils. In this work, a comparison on various regularization methods which are employed to numerically reconstruct a divergence-free cylindrical surface of current distribution is investigated. It is found that a coil current pattern is very sensitive to the modes of the basis function describing the current densities on the coil surface; and iterative regularization techniques generally produce better B(1) field profiles compared with direct approaches.