Magnetic particle imaging (MPI) estimates the spatial distribution of
super-paramagnetic iron-oxide nanoparticles (SPIOs) via the
magnetization response of the particles subjected to static and
ocillatory magnetic fields. This book focuses on the physics of the
SPIOs with emphasis to the application in MPI and gives a brief
introduction to the related particle physics. Stochastical Langevin
equations are used to simulate the magnetization response. The
stochastic differential equations, which incorporate the Néel and the
Brown relaxation processes, are derived in detail and solved
numerically. The solutions are validated with respect to the related
Fokker-Planck equation. Subsequently, simulation studies are carried out
to compare different particle parameters like the hydrodynamic diameter
or the particle anisotropy with respect to the frequency of the magnetic
excitation fields. In addition, a less complex particle model based on
ordinary differential equations is presented to fit measurement data of
a magnetic particle spectrometer. This optimization task is carried out
by a new 2-dimensional continuous genetic algorithm.