Main Article Content
Copyright (c) 2022 Masaomi Washino, Kota Nomura, Kazuki Yamauchi, Tetsuya Matsuda, Yasuaki Susumu, Satoshi Seino, Takashi Nakagawa, Toshiyasu Sakane, Toshihiko Kiwa, Shun Tonooka
This work is licensed under a Creative Commons Attribution 4.0 International License.
Magnetic Particle Imaging (MPI) is an imaging modality that directly detects the nonlinear response of magnetic nanoparticles (MNPs). Spatial encoding is realized by saturating the magnetic moment of MNPs most everywhere except in the special point called the field free reagion in which magnetic field vanishes. Recently, it has been shown that the sensitivity of MPI can be improved by using a field free line (FFL) in which the field free region formed as a line. We developed a MPI equipmemt with FFL using a neodymium magnet and an iron yoke, and magnetic particle imaging of a mouse brain phantom was successfully performed. In addition, we studied the magnetization response of MNPs in the brain and found that the magnetic response of magnetic moment to external magnetic field in the brain is different from that in buffer solution.
 T. Yoshida, S. Bai, A. Hirokawa, K. Tanabe, K. Enpuku, Dynamics of Magnetization and Easy Axis of Individual Ferromagnetic Nanoparticle Subject to Anisotropy and Thermal Fluctuations, J. Magn. Magn. Mat., 380, 105 (2015).
 R. M. Ferguson, K. R. Minard, and K. M. Krishnan, Optimization of nanoparticle core size for magnetic particle imaging, J. Magn. Magn. Mater, 321, 10 (2009).
 K. Murase, S. Hiratsuka, R. Song, and Y. Takeuchi, Development of a system for magnetic particle imaging using neodymium magnets and gradiometer, Japanese Journal of Applied Physics 53, 067001 (2014).
 K. Jinno, T. Kiwa et al., Magnetic characterization change by solutions of magnetic nanoparticles in liquid-phase magnetic immunoassay, AIP Advances 9, 125317 (2019).