Superspeed Bolus Visualization for Vascular Magnetic Particle Imaging.

Magnetic Particle Imaging (MPI) is a fast imaging technique to visualize the distribution of superparamagnetic iron-oxide nanoparticles (SPIONs). For spatial encoding, a field free area is moved rapidly through the field of view (FOV) generating localized signal. Fast moving samples, e.g., a bolus of SPIONs traveling through the large veins in the human body carried by blood flow with velocities in the order of ~45 cm/s, cause temporal blurring in MPI measurements using common sequences and reconstruction techniques. This hampers the evaluation of dynamics of fast moving samples. In this manuscript, a first study on fast moving samples visualized within an MPI scanner is demonstrated. By optimizing parameters for imaging and reconstruction, the dynamics of a fast moving bolus at different velocities can be visualized with high temporal resolution without blurring artifacts.