A custom low-noise preamplifier for Magnetic Particle Imaging

The sensitivity of Magnetic Particle Imaging (MPI), at fewer than 1000 detectable iron-labeled cells, is already comparable to imaging techniques like nuclear medicine [1-2]. However, the true physical sensitivity limits in MPI have not yet been achieved. Importantly, the preamplifier stage of an MPI receiver chain must be optimized to achieve low noise figures (NF) for the reactive inductor sensors used in MPI [3]. For FET-based amplifiers, this can be achieved through the parallelization of multiple amplifiers [3], or through increasing the number of turns in the receiver coil, or through the use of a matching transformer [4]. The work presented here is the development of a MPI preamplifier that is noise-matched to standard MPI preclinical receiver systems. In particular, we aim to achieve 3 dB noise figure for a high inductance receiver coil (>300 μH) at a bandwidth approximately 400 kHz and gain >1000.