A high impedance radio-frequency system improves the decoupling between receiving coils in MRI

The decoupling between coils significantly impacts the amount of independent information between channels in a receiver coil array. Using a pre-amplifier with a low input impedance is limited by the technology in achieving the lowest possible impedance, typically around a few ohms. Here we propose a strategy to improve the decoupling between coil elements in a receiver array by increasing the impedance of the coil system. Simulations and bench measurements show that increasing the impedance from a typical 50 ohm to around 1,000 ohm can increase the decoupling by 25 dB.