Tracking system to monitor the position and orientation of a device using multiplexed magnetic resonance detection

A method for tracing a location of at least one invasive device within a subject employing magnetic resonance (MR) comprising the steps of:

• a) applying a homogeneous magnetic field having substantially uniform amplitude over said subject;
• b) transmitting radiofrequency (rf) energy into said subject of a selected duration, amplitude and frequency to cause nutation of a selected ensemble of spins within said subject;
• c) varying the amplitude of the magnetic field in at least one spatial dimension over said subject over time causing the ensemble of spins within said subject to emit an MR response signal;
• d) detecting an MR response signal from a selected ensemble of spins from each of a plurality of rf coils attached to the at least one invasive device;
• e) processing the detected MR resonance signals;
• f) calculating a location and orientation of the at least one invasive device from the processed MR response signals;
• and
• g) displaying the location of said invasive device to a operator.

A (MR) tracking system comprising:

• a) an invasive device adapted to be inserted into a subject;
• b) static magnetic field means for applying a homogeneous magnetic field having substantially uniform amplitude over the subject;
• c) radiofrequency (rf) transmitter means attached to the at least one invasive device adapted for transmitting rf energy into the subject of a selected duration, amplitude and frequency to cause nutation of a selected ensemble of spins within the subject;
• d) gradient means adapted for varying the amplitude of the magnetic field in at least one spatial dimension over the subject over time causing the selected ensemble of spins to emit an MR response signal;
• e) a plurality of rf coils each adapted for detecting a different respective MR response signal from the ensemble of spins in its vicinity;
• f) receiver means coupled to the rf coils adapted for processing the detected MR response signals from the selected ensemble of spins;
• g) calculation means adapted for calculating a location and orientation of the invasive device from the detected MR response signals;
• h) controller connected to the transmitter means, the receiver means, the calculation means and the gradient means, adapted for activating the rf transmitter means, the detection means, the calculation means and the gradient means according to a desired magnetic resonance sequence;
• and
• i) display means connected to the calculation means adapted for displaying the location of the invasive device to an operator.