First phantom and in vivo MPI images with an extended field of view

Abstract

Magnetic Particle Imaging (MPI) is a high-potential new medical imaging modality that has been introduced in 2005. MPI uses the non-linear magnetization behavior of iron-oxide based nano-particles, named tracer, to perform quantitative measurements of their local concentration. Previous publications demonstrated the feasibility of real-time in vivo 3D imaging with clinical concentration of Resovist®. Given MPI's fast and sensitive imaging as well as its overall versatility, it has potential to support various medical applications spanning from diagnostics to therapy. As an example, ongoing research investigates the use of MPI in cardiovascular diagnostics for myocardial perfusion measurement. While previous publications reported results from experimental systems with limited bore size (3cm), this contribution presents first phantom and in vivo images acquired on the next hardware generation, an experimental system with an effective bore size of 12cm. The system is designed for pre-clinical studies and can capture image data from an extended field of view compared to the previous, experimental system. The contribution introduces concepts for the encoding of a larger field of view by means of additional magnetic fields, named focus-fields, and outlines the path to stitching of images from multiple focus field settings, called "multi-station reconstruction". To prove the feasibility of imaging of an extended field of view, volumetric images of a moving phantom as well as of a living rat were acquired.