A system for MR imaging of a body placed in an examination volume including main coils for establishing a substantially homogeneous main magnetic field in the examination volume, gradient coils for generating switched magnetic field gradients superimposed upon the main magnetic field, RF coils for radiating RF signals towards the body, a controller for controlling the generation of the magnetic field gradients and the RF signals, a processor for forming MR images from received MR signal samples, and an object having an RF antenna for receiving RF signals generated by the RF coils which are configured to generate circularly polarized RF signals having a selectable sense of rotation.