Distributed self-capacitance of magnetic resonance imaging birdcage coils.

Presented is a theoretical description of the self-capacitance of a low-pass birdcage coil. The problem considered is that the modification of the distributed self-capacitance produced by the electric interaction between the coil and a cylindrical Faraday screen and illustrates the phenomenon of coil self-capacitance as well as the influence of Faraday screens. Changes in coil self-capacitance produced by the presence of the screens are shown to be consistent with measured shifts in coil resonant frequencies.