Towards a Fully Integrated Preclinical Field-Free Line MPI Scanner

Abstract

As a radiation-free, highly sensitive and high resolution imaging technique, magnetic particle imaging promises
to provide deep insights into biological processes of living specimen. A permanent magnet-based, field-free line
(FFL) scanner for the scope of molecular imaging on cell level or in small animals is presented. The scanner
is based on two rotatable discretized Halbach dipole rings creating a FFL between them, that is orthogonal
to their common axis. Using a solenoid coil the FFL can be translated in the imaging plane. The combined
rotation and translation of the FFL results in a native 2D image acquisition that can be extended to 3D by a
moving table approach. Due to the high gradient of 5 Tm????1, the addition of a focus field is needed to extend the
field of view to the full 40mm bore size. Both the drive and focus field are generated by superimposed currents
in a single coil. The currents are driven by two separate sources which are decoupled by a protection filter.
Signal acquisition is realized with a gradiometric pickup coil and first phantom experiments suggest an in-plane
spatial resolution smaller than 0.7mm. The hardware and software concept of the scanner will be presented, as
well as the iterative improvements and design decisions that were made based on inter-dependencies between
the individual components. In conclusion, a platform for a scanner will be shown that is aimed directly at
molecular imaging.