Radiofrequency Coil Array Design and Optimisation for Magnetic Resonance Low Field Imaging

Radiofrequency (RF) coil phased arrays are getting more and more important for accelerating the imaging speed and for gaining better signal to noise ratio (SNR) in magnetic resonance imaging (MRI). The approach is conceptually similar to phased array used in radar techniques hence it is used to be called MRI phased array coils. To get maximum benefits from this technique, coil and preamp decoupling and coil geometry optimization are necessary to ensure independence of the individual coil channels. Qualitative design and a method for optimization of geometric properties of the coil elements in phased arrays, with aim to increase SNR, G-factor and to limit noise correlation, are proposed in this paper. Simulating by the finite element method (FEM) using Comsol Multiphysics we obtained the sensitivity maps of coils. The introduced Matlab program is primarily calculating the Gfactor along with other parameters that can be calculated from sensitivity maps. By an optimization algorithm the program is setting the parameters of the coil and afterwards is driving the FEM simulations.