Patent ID: 7683621

Claim:
A magnetic resonance imaging (MRI) apparatus comprising: a plurality of gradient coils positioned about a bore of a magnet; an RF coil assembly coupled to a pulse generator to emit RF pulse sequences and arranged to receive resulting MR signals from a subject of interest; and a system control coupled to the plurality of gradient coils and the RF coil assembly, the system control programmed to: cause the RF coil assembly to emit a first RF pulse comprising a first pair of two-dimensional (2D) spatially selective beams, each of the beams being directed to a respective tagging location in the subject of interest and wherein the tagging locations are equidistant from a pre-determined point-of-interest; acquire a first series of MR images from the subject of interest; identify the first pair of 2D spatially selective beams in each MR image in the first series of MR images; and track a position of the point-of-interest based on the identified 2D spatially selective beams in the first series of MR images.