Comparison of two alternative sequences for human in-vivo brain MR Current Density Imaging (MRCDI)

MRCDI is a novel technique, utilizing dierent phase-sensitive MR methods for non-invasive measurements of weak currents in the human body, which is important in several neuroscience applications. Here, we compare the in-vivo performance of two dierent MR methods, multi-echo spin echo (MESE) and steady-state free precession free induction decay (SSFP-FID), with single- vs. multi-gradient-echo readouts. We demonstrate that multi-gradient-echo readouts improve both methods. We validate the linear dependence of the measured current-induced magnetic eld on the injected current strength for both methods, and propose the more ecientSSFP-FID method as being well suited for highly sensitive single-slice human in-vivo MRCDI.