On the effect of finite magnetic relaxation on the magnetic particle imaging performance of magnetic nanoparticles

Magnetic particle imaging is an emerging imaging technique where contrast is provided by the non-linear response of magnetic nanoparticle tracers to an applied magnetic field consisting of a scanned field free point. Commonly the magnetic response of the nanoparticles is assumed to be instantaneous, which is at odds with experimental evidence that finite relaxation affects both the signal and resolution provided by the tracers. Here, we apply rotational Brownian dynamics simulations to obtain insight into the effect of finite relaxation and of the conditions of the magnetic field on the performance of magnetic nanoparticle tracers used for magnetic particle imaging.