Speaker
Description
Magnetic Particle Imaging (MPI) is an imaging modality that uses the nonlinear magnetization characteristics of superparamagnetic iron oxide particles (SPIOs) and a relatively high magnetic moment compared to general paramagnetic materials. Since MPI can directly measure the concentration and location of SPIOs distributed in space, it is one of the emerging medical imaging techniques that are being studied for its use in tumor imaging, magnetic hyperthermia, cardiovascular and cell tracking(1). In all MPIs developed to date, the concentration and location information of SPIOs is obtained by forming a Field Free Line (FFL) or Field Free Point (FFP) in the space to be measured. Therefore, it is the most essential part from the manufacturing method to the resolution of the equipment according to the method of forming FFL and FFP in MPI. In this study, instead of using electromagnets or large magnets, we would like to present MPI, which generates FFLs by arranging small magnets in three-dimension and moves them mechanically (2). By applying the above FFL generating system, there is no need for drive coils, cooling equipment, and power supply systems required to obtain location information from MPI that has been developed so far. In order to secure the usefulness of the above MPI system, images were obtained using capillaries filled with SPIOs at intervals of 2 to 10 mm and spiral-shaped tubing. As a result of the experiment, it was possible to secure images up to 3D with a resolution of about 2.0 mm. In addition, it showed that even specific letters can be imaged successfully, showing the possibility of being used as medical imaging equipment or molecular imaging equipment in the various fields mentioned above. Accordingly, the MPI developed through this study was used to track SPIOs deposited in organs after SPIOs were injected into small animals for testing. And, as a result of checking the MPI image and the concentration of MNP after extraction, it was confirmed that the MPI image information and the concentration matched (3). Therefore, the results of this study showed that the method proposed in this study has advantages in manufacturing and operation compared to the electromagnet type MPI, which consumes a huge amount of power, or the MPI using large magnets.
References
(1) Talebloo, N., Gudi, M., Robertson, N. & Wang, P. Magnetic Particle Imaging: Current Applications in Biomedical Research. Journal of magnetic resonance imaging : JMRI 51, 1659-1668, doi:10.1002/jmri.26875 (2020).
(2) Choi, S.-M. et al. A novel three-dimensional magnetic particle imaging system based on the frequency mixing for the point-of-care diagnostics. Scientific Reports 10, 11833, doi:10.1038/s41598-020-68864-9 (2020).
(3) P-J, Park. et. al. In vivo Preclinical Tumor-Specific Imaging of Superparamagnetic Iron Oxide Nanoparticles Using Magnetic Particle Imaging for Cancer Diagnosis. Int. Journal of Nanomedicien, 17,3711-3722 (2022).
| Keywords | MPI, SPIOs, Permanent Magnets |
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