Safety Aspects of Utilized Instruments for Cardiovascular Interventions in Magnetic Particle Imaging (MPI)

Magnetic particle imaging (MPI) has been introduced in 2005 [1] and has emerged as a new three-dimensional imaging method delivering images with a high spatial and temporal resolution while free of ionizing radiation. Imaging is based on the nonlinear magnetic response of superparamagnetic iron oxide nanoparticles (SPIOs) in a sinusoidal oscillating magnetic excitation field. The modality is able to directly quantify the spatial distribution of SPIOs [1-5]. Recent studies demonstrated the feasibility of Magnetic particle spectroscopy (MPS) to differentiate between signal-generating and non signal-generating devices and to visualize commercially available catheters and guide wires in MPI by loading or coating them with superparamagnetic iron oxide particles (SPIOs) [6,7]. Thus, MPI seems to be a promising imaging tool for cardiovascular interventions [8,9]. However, there are no studies addressing safety aspects, such as heating of interventional devices in MPI although this is one of the most important safety issues and obstacles for in vivo use in MPI. For this purpose, several commercially available catheters and guide wires were tested in this study regarding heating corresponding to signal characteristics in the MPI scanner.