Recently, Associate Professor Li Tanping of the School of Physics, as the corresponding author, published an academic paper entitled "Gradient Based Pulsed Exception and Relaxation Encoding in Magnetic Particle Imaging" in IEEE Transaction on Medical Imaging (top journal of JCR District I, Chinese Academy of Sciences, impact factor=11.037), the top journal in the field of medical imaging. An innovative imaging technology of magnetic nanoparticles based on gradient pulse excitation magnetic field for spatial coding was proposed. Based on Langevin equation, the dynamic and thermodynamic properties of magnetic particles were studied.

In this paper, the gradient excitation magnetic field is introduced into Magnetic Particle Imaging (MPI) to achieve spatial coding, that is, the gradient pulse magnetic field is used to excite magnetic nanoparticles and generate relaxation attenuation signals, and the magnetic nanoparticles are excited along the free line of the magnetic field, and then the high-resolution one-dimensional image on the FFL is reconstructed using the system matrix. This innovative method in this paper is called "relaxation encoding", which is considered as a supplement to the "frequency encoding" and "phase encoding" of MPI and can effectively improve image resolution to meet the needs of clinical patient scanning. It is expected to be applied to achieve high-resolution human clinical imaging.

Other units involved in this work include the School of Computer Science and Technology and the School of Life Science and Technology of Xidian University, Lanzhou University, and the Institute of Automation of the Chinese Academy of Sciences. This work has been supported by the projects of the National Key R&D Plan and the National Natural Science Foundation of China.

LINK：https://ieeexplore.ieee.org/document/9837082