Test-Retest Reliability of Diffusion Measures in Cerebral White Matter: A Multiband Diffusion MRI Study

Background: To investigate the test-retest (TRT) reliability of the diffusion measures in cerebral white matter obtained from the diffusion MRI dataset acquired with multiband acceleration. Methods: With the multiband diffusion MRI dataset with two repeated scanning sessions, the TRT reliability of diffusion measures (fractional anisotropy [FA], mean diffusivity [MD], primary diffusivity [PD] and transverse diffusivity [TD]) was investigated through several fully automated analysis methods, including two voxel-level analyses (voxel-based analysis [VBA] and tract-based spatial statistics [TBSS]) and an atlas ROI-based analysis. The reproducibility was assessed by the intra-class correlation coefficient (ICC). Results: Our results demonstrated moderate to high reproducibility (ICC > 0.4) of diffusion measures from the multiband EPI sequence with different analysis approaches. Across different measures, FA exhibited the highest reproducibility (mean ICC = 0.70), while MD showed the lowest reliability (mean ICC = 0.55) (P=0.006). Additionally, ICCs varied across different tract ROIs: Commissural tracts showed higher reproducibility than other categories of tracts (projection, association and brainstem), while the brainstem tracts exhibited the poorest reliability (P=0.004). Conclusion: Our findings suggest a potential utility of the multiband EPI sequence for exploring individual differences of cerebral white matter and provide reference for future white matter studies.