System calibration unit for magnetic particle imaging: Focus field based system function

Abstract

Magnetic particle imaging usually requires image reconstruction in order to obtain the distribution of the superparamagnetic iron oxide particle concentration from the measured signal. An integral part of the reconstruction is the system function, which relates the superparamagnetic iron oxide distribution to the signal it generates in the MPI scanner. Traditionally, the system function is obtained by measuring the signal generated by a known point-like concentration throughout the imaging volume. This however, requires a robot and is very time consuming. In this contribution we demonstrate a method for estimating the system function using focus fields, which avoids the need for a robot.