Discrimination of Different Nanoparticles Based on Narrowband Magnetic Particle Imaging

Magnetic Particle Imaging (MPI) is a new imaging modality that allows to visualize the spatial distribution of magnetic nanoparticles (MNPs) based on the measurement of their nonlinear dynamic magnetization. In MPI, the unique spectral signatures of different particles induced in an ac magnetic field allow to distinguish the types of MNPs via color-MPI techniques, which is of great importance to disease diagnosis and treatment. Successful signal separation has been reported with broadband MPI approach. In this paper, a new method of dual-color MPI based on single-harmonic-based narrowband MPI approach is proposed to quantitatively visualize the spatial distribution of two different MNPs. The imaging principle of narrow-band MPI is introduced while the mathematical expression of dual-color MPI is derived. Simulations are performed to evaluate the performance of the proposed method for the discrimination of the different MNPs. Only the 3^rd harmonics are used for image reconstruction in the narrowband MPI. A row-based iterative reconstruction is adopted in the simulations. Different parameters in the algorithm are tested and the reconstruction images are compared for parameter selection. Simulation results confirm the feasibility of the proposed approach for effective discrimination of two different MNPs. The cross-talk between different channels is analyzed and discussed in the last section.