In vivo liver visualizations with magnetic particle imaging based on the calibration measurement approach

Magnetic particle imaging (MPI) facilitates the rapid determination of three-dimensional in vivo magnetic nanoparticle distributions. In this work, liver MPI following intravenous injections of ferucarbotran (Resovist®) was studied. The image reconstruction was based on a calibration measurement, the so called system function. The application of an enhanced system function sample reflecting the particle mobility and aggregation status of ferucarbotran resulted in significantly improved image reconstructions. The finding was supported by characterizations of different ferucarbotran compositions with the magnetorelaxometry and magnetic particle spectroscopy technique, for instance, ferucarbotran embedded in freeze-dried mannitol sugar exhibited similar results compared to harvested liver tissue after ferucarbotran injection. In addition, the combination of multiple shifted measurement patches for a joint reconstruction of the MPI data increased the covering of liver MPI on magnetic resonance images noticeably.