Fast and Efficient Birdcage Coil Design Process for High Field MRI System by Combining Equivalent Circuit Model and 3D Electromagnetic Simulation

Abstract

A novel method has been established to mitigate the complexity of a birdcage coil design process for use in a MRI (Magnetic Resonance Imaging) system. It can reduce the time consumptions of the typical coil design process based on 3D (three-dimensional) simulations. The method combines an equivalent circuit model and a 3D electromagnetic simulation. It makes it possible to understand the coil properties intuitively and to solve the major engineering problems by using just the circuit model not by using the complex 3D simulation. The concept of the dominant resonance path length of the coil has also been introduced, which facilitates the design process by considering the skin effect of the coil. We have verified that the skin effect of the birdcage coil can be evaluated through a simple circular loop circuit instead of the whole 3D geometry. Base on the design proposed method, we also have successfully demonstrated that the birdcage coil based on a FPCB (Flexible Printed Circuit board) technique can be used in high filed (3.0 T and 4.7 T) MRI systems for small animal NMR (Nuclear Magnetic Resonance) imaging.