An optimized receive-chain for MPI

The drive field suppression and the particle signal amplification are key components in Magnetic Particle Imaging (MPI) [1]. However, for high signal-to-noise ratio (SNR) the noise contribution of the receive chain has to be minimized as well. Main noise sources are the receive coil, the coils in the filter stage and the semiconductor elements in the pre-amplifier. The voltage induced by the drive field is about six orders of magnitude higher then the particle signal [2], and must be suppressed by at least 80 dB to keep the pre-amplifier in its linear region. Usually this problem is adressed by applying a notch filter [1] to remove the drive field signal as well as the particle signal at the excitation frequency prior to amplifying the signal. However, this removes the strongest particle signal as well, and therefore induces problems to the reconstruction which have to be addressed, e.g. DC drifts in x-space MPI [3].