Improving the Imaging Quality in Magnetic Particle Imaging by a Traveling Phase Trajectory

Introduction: Magnetic particle imaging (MPI) is a new quantitative tomographic imaging method for measuring the spatial distribution of super-paramagnetic iron-oxide nanoparticles (SPIOs) in real-time [1, 2, 3, 4]. MPI takes advantage of the nonlinear magnetization behavior of the SPIOs. Spatial encoding is achieved by moving a field-free point (FFP) through the field of interest. For moving the FFP, different trajectories were analyzed [5]. The Lissajous curve was evaluated as an adequate trajectory and is used in actual scanners. In these scanner implementations, the different transmit frequencies cannot be varied due to resonance matching of the transmit coils. This results in a fixed sampling trajectory as well as in fixed resolution and repetition time. In this contribution, we present a new method, which allows for changing the sampling trajectory and the resulting resolution.