Resolution improvement by decreasing the drive field amplitude

In Magnetic Particle Imaging the signal is generated by an oscillating magnetic field, the so-called Drive Field. Thereby, increasing the Drive Field amplitude (DFA) yields higher signal strength [1]. Furthermore, the sensitive area which is covered by the field-free point is determined by the ratio between the DFA and the gradient strength [2]. This area scaling with the DFA is referred to as drive field field-of-view (DF-FoV). While the spatial shape of a certain system function component (SFC) does not change with varying DFA [3], its spatial extent scales with the DFA and therefore the same component describes a different resolution for different DFA values. In general, decreasing the DFA reduces the signal strength of each SFC, but at the same time SFCs determining a certain resolution level typically appear at lower frequencies with higher signal intensities. In this work a 2D simulation study is performed to evaluate the effect of decreasing the DFA.