  Magnetic Particle Imaging (MPI) is a novel and versatile imaging modality
developing towards human application. When up-scaling to human size, the
sensitivity of the systems naturally drops as the coil sensitivity depends on
the bore diameter. Thus, new methods to push the sensitivity limit further have
to be investigated to cope for this loss. In this paper a dedicated surface
coil for mice is developed, improving the sensitivity in cerebral imaging
applications. Similar to MRI the developed surface coil improves the
sensitivity due to the closer vicinity to the region of interest. With the
developed surface coil presented in this work, it is possible to image tracer
samples containing only 896 pg Fe and detect even small vessels and anatomical
structures within a wild type mouse model. As current sensitivity measures
require a tracer system a new method for determining a sensitivity measure
without this requirement is presented and verified to enable comparison between
MPI receiver systems.
