Magnetic Particle Imaging Using an Optically Pumped Magnetometer Coupled With a Flux Transformer

We propose a magnetic particle imaging (MPI) scanner using an optically pumped magnetometer (OPM) that is connected via a flux transformer. The OPM has high sensitivity, but it cannot operate in the excitation magnetic field used to magnetize the magnetic nanoparticles because of its narrow dynamic range. As a result, a flux transformer is used in this work to overcome the problem. Furthermore, the excitation current amplitude was maintained at a constant level using real-time feedback control and wavelet denoising was used to reduce the measurement noise. The results demonstrate that the position of a 100 μg-Fe Resovist magnetic nanoparticle sample can be estimated successfully via an inverse problem analysis approach to within an error of 5 mm even when the sample is located at depths of 25–50 mm from the pickup coil.