Simultaneous Reconstruction and Resolution Enhancement for Magnetic Particle Imaging

Spatial resolution is an essential parameter for magnetic particle imaging (MPI). The spatial resolution of MPI depends, among other things, on the particles diameter and sampling frequency. The spatial resolution increases when increasing the particle diameter. However, large particles suffer from relaxation effects and are not preferred in some applications. On the other hand, spatial resolution increases with the sampling frequency, which in turn increases the number of sampling points. As an alternative solution for resolution enhancement, super-resolution (SR) is proved to be beneficial in improving the image quality of many medical imaging systems without the need for significant hardware alteration. In this paper, we propose to use small particle diameter and low sampling frequency to obtain multiple low-resolution (LR) magnetic particle measurements and apply a resolution enhancement technique to reconstruct a higher resolution magnetic particle concentration. Unlike the conventional SR techniques, we propose to reconstruct a high-resolution concentration from the measured LR signals instead of reconstructing LR concentrations and then post-process these concentrations to get a higher resolution concentration. Simulation results show that the resolution of MPI can be increased by incorporating resolution enhancement technique without increasing the particle diameter. In addition, simulation results show that using simultaneous reconstruction and resolution enhancement results in sharper concentrations and that this procedure is more robust against noise than using SR as a post-process.