A radio-frequency (RF) coil system that simplifies multi-nuclear magnetic resonance (MR) imaging is disclosed herein. The RF coil system comprises a transmitter coil (102) for transmitting an RF signal to excite a target region of a subject. The RF coil system also comprises an independent planar receiver coil assembly (110) for receiving an MR signal from at least a portion of the target region, the planar receiver coil assembly (110) being configured to include an on-board digital receiver circuit (112) for processing the received MR signal.