An overview on the recent progress in the biomedical application of
magnetic materials and on the most used magnetic resonance imaging techniques is
presented. After briefly mentioning the basic aspects of Magnetic Resonance Imaging
(MRI), some of the most frequently used pulse sequences are illustrated with
particular emphasis on those used in Diffusion Tensor Imaging, Magnetic Resonance
Spectroscopy and functional MRI. Then the basis of the Dynamical Nuclear Polarization
technique, which allows to perform in vivo molecular imaging of the metabolic
processes, is presented. The physical properties of smart nanosized magnetic materials
which can further improve the potential of these diagnostic techniques are
described in the following sections. These magnetic nanoparticles may be used as
MRI contrast agents, for the magnetic transport and drug delivery or even for the
therapy of certain pathologies through magnetic fluid hyperthermia. The possible
combination of some of these functionalities into just one multifunctional nanoparticle
is also considered