A magnetic resonance system includes a magnetic resonance scanner (8) and a magnetic resonance scan controller (24). A plurality of markers (40, 140) are attached to the subject to monitor motion of a portion of a subject within an examination region. A motion control unit receives motion data from the markers indicative of the motion and controls the magnetic scan controller to adjust scan parameters to compensate for the motion. In one embodiment, the marker (40) includes a substance (44) which resonates at a characteristic frequency in response to radio excitations by the magnetic resonance scanner. A controller (52) switches an inductive circuit (48, 50) disposed adjacent the substance between a tuned state and a detuned state.