A recent study discovered discordant changes in quantitative susceptibility mapping (QSM) and diffusion tensor imaging (DTI) metrics within the cingulate gyri and forceps major. Therefore, this may potentially reflect the influence of paramagnetic substrates such as iron, which could be decreased along these normal-appearing white matter (NAWM) tracts in multiple sclerosis (MS). 20 relapsing–remitting MS patients and 20 age-matched healthy controls (HC) were recruited for this prospective study. QS, radial diffusivity (RD), fractional anisotropy (FA), and R2* maps within the whole brain as well as individual tracts were generated for comparison between NAWM and HC white matter (HCWM). Researchers found:
- MS lesions demonstrated significant differences in QS, FA, RD, and R2* compared to HCWM.
- These metrics did not show a significant difference between whole-brain NAWM and HCWM.
- Among NAWM tracts, the cingulate gyri demonstrated significantly decreased QS compared to HCWM.
- The forceps major showed significant differences in FA and RD without corresponding changes in QS.
Yu FF, Chiang FL, Stephens N, et al. Characterization of normal-appearing white matter in multiple sclerosis using quantitative susceptibility mapping in conjunction with diffusion tensor imaging. [Published online ahead of print December 12, 2018]. Neuroradiology. doi:10.1007/s00234-018-2137-7.