A comparison of in vivo MRI based cortical myelin mapping using T1w/T2w and R1 mapping at 3T

Raw and pre-processed data associated with the publication:
Zahra Shams, David G. Norris, José P. Marques, A comparison of in vivo MRI based cortical myelin mapping using T1w/T2w and R1 mapping at 3T, PLOSone, 2019 (DOI: 10.1371/journal.pone.0218089)

Publication abstract:
In this manuscript, we compare two commonly used methods to perform cortical mapping based on myelination of the human neocortex. T1w/T2w and R1 maps with matched total acquisition times were obtained from a young cohort in randomized order and using a test – retest design. Both methodologies showed cortical myelin maps that enhanced similar anatomical features, namely primary sensory regions known to be myelin rich. T1w/T2w maps showed increased robustness to movement artifacts in comparison to R1 maps, while the test re-test reproducibility of both methods was comparable. Myelin maps were parcellated into Brodmann areas and it was found that both methods showed comparable variability within each region, but R1 maps showed an increased distinguishability between neighbouring regions and increased variability between subjects. In combination with the test re-test evaluation, we concluded that this increased variability between subjects reflects relevant tissue variability. A high level of correlation was found between the R1 and T1w/T2w regions with regions of higher deviations being co-localized with those where the transmit RF field deviated most from its nominal value. We conclude that R1 mapping strategies might be preferable when studying different population cohorts where cortical properties are expected to be altered while T1w/T2w mapping will have advantages when performing cortical based segmentation.