Magnetic particle imaging allows to determine the spatial distribution of magnetic nanoparticles in vivo. The system matrix in magnetic particle imaging is commonly acquired in a tedious calibration scan and requires to measure the system response at numerous positions in the field-of-view. In this paper, we propose a method that significantly reduces the number of required calibration scans. It exploits the special structure of the system matrix and applies sparse reconstruction techniques. Experiments show that the number of calibration scans can be reduced by a factor of ten with only marginal loss of image quality.
