Does RF spoiling enhance human in-vivo brain MR Current Density Imaging (MRCDI)?

MRCDI is an emerging modality for non-invasive measurement of weak currents in the human brain, which is important in several neuroscientific applications. It is based on current-induced field measurements and requires high sensitivity to the extrinsic field changes. Measurement sensitivity can be compromised by irrelevant field changes caused by physiological variation. Here, we compare the performance of the so far most sensitive MRCDI method based on steady-state free precession free induction decay (SSFP-FID) with its RF-spoiled counterpart fast low angle shot (FLASH). No significant sensitivity differences were observed in slices covering the upper part of the brain, butSSFP-FID had ~20% lower noise floors in lower slices. For the relevant acquisition parameters, FLASH exhibits no remarkable image quality enhancements in 2D.