  In magnetic particle imaging (MPI), simultaneous excitation and signal
acquisition leads to direct feedthrough interference. While this interference
can be mitigated up to some extent with passive compensation, its time-varying
nature necessitates active compensation methods to achieve the sensitivity
levels needed for applications such as stem cell tracking. We have recently
proposed an active compensation technique for MRI, which uses a vector
modulator and a lookup-table-based algorithm for reducing the direct
feedthrough in the analog domain. Here, we adapt this technique to MPI,
demonstrating a successful recovery of the fundamental frequency and a
significant increase in detection sensitivity.
