| 摘要 |
A method related to Magnetic Particle Imaging (MPI) includes a signal processing step in which MPI time signals are acquired and successive acquisition cycles are completed within one scanning period. From the scanning period, an image acquisition period is selected for which a composite time signal is generated by concatenating measured values acquired in immediate succession. A corrected time signal is determined from the composite time signal by windowing, performing a Fourier transform, and reducing a number of frequency values by eliminating intermediate frequencies of the Fourier transform of the windowed, composite time signal. In a reconstruction step, a spatial assignment and/or distribution of the magnetic particles is computed, and in an outputting step, the results of the reconstruction and/or one or more parameters derived therefrom are stored and/or displayed. |
| 主权项 |
1. A method of determining a spatial assignment and/or spatial distribution of magnetic particles in a specified analysis volume performed by a Magnetic Particle Imaging (MPI) measuring device, comprising:
in an acquisition step performed with a receiving device of the MPI measuring device, acquiring m MPI time signals with a total of m·N measured values Aq, where q=0, . . . , m·N−1, completing m successive acquisition cycles within a scanning period, and in each of the acquisition cycles acquiring an MPI time signal of duration T0 with N time-assigned measured values by repeatedly executing a specified measurement sequence, where m≧1 and N≧1; in a signal processing step:
a) selecting one image acquisition period from the scanning period and, for the selected image acquisition period, generating a composite time signal z with signal values zj, where j=0, . . . , n·N−1, by concatenating n·N measured values acquired in immediate succession, where n≦m, acquiring at a desired starting time of the image acquisition period a measured value Ar, with 0≦r≦(m−n)·N−1, and assigning the measured value Ar to a start signal value z0 so that z0=Ar, and an image acquisition period of duration n·T0, is covered; andb) determining a corrected time signal {tilde over (z)} from the composite time signal z, wherein the determining the corrected time signal {tilde over (z)} comprises windowing the composite time signal z to produce a windowed composite time signal, computing a Fourier transform of the windowed composite time signal to produce a windowed, Fourier-transformed, composite time signal having a number of frequency values, and reducing the number of frequency values by eliminating intermediate frequencies among the number of frequency values to produce a reduced frequency spectrum; in a reconstruction step, computing the spatial assignment and/or the spatial distribution of the magnetic particles from either the reduced frequency spectrum or the corrected time signal {tilde over (z)}; and in an outputting step, providing results of the reconstruction and/or at least one parameter derived from the reconstruction. |
