Towards Addressing Nanoparticle Relaxation in Model-Based Reconstruction

Magnetic Particle Imaging (MPI) is a tracer-based imaging modality that uses superparamagnetic nanoparticles as tracer. The Langevin model is a simple model that is capable of capturing the overall relation between the measured signal and the particles, but it ignores relaxation effects. Relaxation effects can be accounted for in the Debye model, which introduces a relaxation parameter ?, representing the delay in the alignment of the nanoparticles to the magnetic field. Starting from the Debye model, we propose a relaxation adaption step to account for the delay ? in model-based reconstructions that use the Langevin model.