Imaging of Magnetic Nanoparticles Using AC Susceptibility Data

Magnetic nanoparticle tomography (MNT) can estimate the position of magnetic nanoparticles (MNPs) via inverse problem analysis. In MNT studies, a system matrix is experimentally acquired for inverse problem analysis. However, the long acquisition time causes large temperature fluctuations in the excitation coil and electric circuit, resulting in noise in the system matrix. In this study, to remove this noise, the system matrix was calculated using ac susceptibility (ACS) data experimentally obtained via magnetic particle spectroscopy (MPS). The inverse problem was solved using the calculated system matrix. As a result, spatial fluctuation was suppressed. Moreover, the position of MNPs was accurately estimated. These results confirmed that the proposed method is useful for estimating the position of MNPs in MNT systems.