Hybrid stents can be used in cardiovascular applications and in hollow organ tumor therapy. They open the occluded area and can induce local hyperthermia by application of an alternating magnetic field (AMF) destroying cancer cells. Here, we investigate hybrid fibers made of polypropylene (PP) fibers with incorporated magnetic nanoparticles (MNP) via magnetic particle imaging (MPI). An influence of the MNP mobility and MNP agglomeration state as well as the orientation of elongated MNP agglomerations with respect to the drive field of the system matrix reference on the image reconstruction were determined. Best image resolution for a phantom consisting of two parallel fibers was achieved with reconstructions using system matrices of a fiber where MNP agglomerations point in the same direction as the ones of the phantom with respect to the drive field. Changes in MNP mobility, agglomeration state and their preferred directions have effects on the resulting image quality and must be considered in future measurements of complex structures of hybrid fibers
