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 promisesto 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 scanneris based on two rotatable discretized Halbach dipole rings creating a FFL between them, that is orthogonalto their common axis. Using a solenoid coil the FFL can be translated in the imaging plane. The combinedrotation and translation of the FFL results in a native 2D image acquisition that can be extended to 3D by amoving table approach. Due to the high gradient of 5 Tm????1, the addition of a focus field is needed to extend thefield of view to the full 40mm bore size. Both the drive and focus field are generated by superimposed currentsin 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-planespatial resolution smaller than 0.7mm. The hardware and software concept of the scanner will be presented, aswell as the iterative improvements and design decisions that were made based on inter-dependencies betweenthe individual components. In conclusion, a platform for a scanner will be shown that is aimed directly atmolecular imaging.