MPI method

摘要

An MPI method determines calibration and measurement volumes, wherein the calibration volume is larger than the measurement volume and the overall measurement volume is arranged within the calibration volume. Calibration signals are detected and a system matrix S is created. An MPI measuring signal u is recorded, a location-dependent magnetic particle concentration c with magnetic particle concentration values ci within the calibration volume is reconstructed and the magnetic particle concentration values ci are associated with voxels in the calibration volume. Magnetic particle concentration values ci which were associated with voxels outside of the measurement volume are discarded and an MPI image is generated which exclusively contains magnetic particle concentration values ci which were associated with the voxels within the measurement volume. MPI image data are thereby generated with little artefacts within a short time even in case of high magnetic particle densities outside of the measurement volume.

主权项

1. An MPI method for localizing magnetic particles within a test sample, the method comprising the steps of:
a) generating a location-dependent magnetic field having a field-free region; b) determining a calibration volume and a measurement volume, wherein the calibration volume is larger than the measurement volume and the measurement volume is completely within the calibration volume; c) detecting calibration signals Sj; d) creating a system matrix S from the calibration signals Sj; e) recording an MPI measuring signal u; f) applying a magnetic control field in order to move the field-free region; g) repeating steps e) and f) until the field free region is moved through the measurement volume in a measuring sequence; h) reconstructing a location-dependent magnetic particle concentration c with magnetic particle concentration values ci within the calibration volume from the MPI measurement signal and the system matrix S i) associating the magnetic particle concentration values ci with voxels in the calibration volume; j) discarding magnetic particle concentration values ci which are associated with voxels outside of the measurement volume; and k) generating an MPI image which exclusively contains magnetic particle concentration values ci which were associated with voxels of a voxel grid within the measurement volume.