Apparatus and method for influencing and/or detecting magnetic particles

摘要

The present invention relates to an MPI (Magnetic Particle Imaging) apparatus and a method for influencing and/or detecting magnetic particles in a field of view. Rather than moving the FFP (field free point) along a single, time-consuming high density trajectory it is proposed to use a number of low density trajectories with travelling phase, wherein each of said low density trajectories has the form of a closed curve differently located within the field of view.

主权项

1. An apparatus for influencing magnetic particles in a field of view, which apparatus comprises:
selection means comprising a selection field signal generator unit and selection field elements for generating a magnetic selection field having a pattern in space of its magnetic field strength such that a first sub-zone having a low magnetic field strength and a second sub-zone having a higher magnetic field strength are formed in the field of view, drive means comprising drive field signal generator units and drive field coils for changing the position in space of the two sub-zones in the field of view by means of a magnetic drive field so that the magnetization of the magnetic material changes locally, and control means for controlling said drive field signal generator units to generate drive currents for causing the drive field coils to generate a magnetic drive field such that the first sub-zone moves along a number p of predetermined low density trajectories each having the form of a closed curve differently located within the field of view, wherein each drive current has a drive current frequency and a drive current phase, wherein the drive currents are generated such that their drive current frequencies are equal or have a frequency ratio in the range from 0.5 to 0.98 and that the drive current phases of at least one drive current are different for the plurality p of low density trajectories, resulting in a high density sampling of the field of view by said first sub-zone after movement along said number p of predetermined low density trajectories.