Assessing inter-tract independence across microstructural metrics

We aimed to identify potential redundancies in microstructural measures between major white matter tracts and asked which microstructural metrics correlate most within a tract. Using a combination of microstructural imaging techniques, including diffusion imaging, relaxometry and quantitative magnetisation transfer imaging, we identified strong correlations between homologous left and right fasciculi in the cingulum bundles, inferior longitudinal fasciculi, uncinate fasciculi and arcuate fasciculi as well as similar patterns of tissue microstructure between heterologous tracts. However, corticospinal tracts showed weak correlations with other tracts and a unique pattern of inter-metric correlations, suggesting that summarising metrics across all tracts would be inappropriate.