Circular and elliptical birdcage coil design for magnetic resonance imaging

In the design of birdcage coils, the capacitance is dependent on the coil´s dimensions and resonant frequency. This capacitance is obtained by either trial-and-error or by complicated calculations of inductance, capacitance, and resonant frequency. These approaches are either time-consuming or require substantial knowledge of coil theory. A simple method and graphical-user-interface (GUI) software program have been developed to facilitate the design of circular or elliptical birdcage coils. The program encapsulates the detail of calculations with a user-friendly interface. Users are allowed to design their coils with various construction materials, a high-pass (HP) or low-pass (LP) configuration, and can choose whether the birdcage coil is shielded or unshielded. Implemented following the authors´ method, this program can accurately calculate the necessary capacitance, and provides a simple and efficient solution for birdcage coil design. The performance of the program was experimentally verified on several different coils. Deviations between the measured resonant frequency and the desired resonant frequency were less than a few percent