Pulse shaping for localized magnetic resonance tagging

Magnetic resonance tagging is usually achieved by means of a train of non-selective radio-frequency pulses separated by gradient pulses. Thus, the modulation of the M₂ magnetization component expands all over the imaging plane. It has been proposed that the use of selective excitation pulses may limit the modulation only to regions of interest, thus preserving anatomical data in the rest of the image. In this paper, we intend to expand the tagging k-space concept in order to account for pulse selectivity, and offer a prediction and design tool for localized MR tagging sequences.