Effects of scanning rate on relaxation-induced blurring in magnetic particle image

Abstract

We measured the relaxation times of PSFs acquired at a range of scanning rate, which was varied by changing the excitation field strength. As excitation scanning rate increased, measured relaxation times decreased (Figure 1b). This effect is likely due to the stronger magnetic torque acting on the particles. Relaxation field delays were calculated for the same data to observe how relaxation time delays translated to delays in field after taking into account the scanning rate. As the excitation field was scanned faster, relaxation field delays increased (Figure 1c). FWHM measurements followed a similar trend as the relaxation field delays and increased as scanning rate increased (Figure 1d). Although faster scanning decreases relaxation times, increasing scanning rate exacerbates image blur due to relaxation.