PSF, numerical, and phantom simulations. Top row: PSF magnitude and phase for four different frequency-offsets: 0, 50, 150, 250 Hz. The phase images were thresholded with the magnitude image, the phase values were nulled for the corresponding magnitude points with <15% of the peak magnitude. The images are zoomed in to the centre, original FOV=370mm. Middle row: The effects of those frequency-offsets on a numerical simulated homogeneous disc. Bottom row: Phantom results for the same frequency-offsets.