Fig. 2

TBSS results showing the differences in diffusion indices between moderate COPD patients and the comparison group Note: Green represents the mean WM skeleton of all subjects; yellow, red and blue represent regions with increased MD, increased AD and increased RD, respectively, in moderate COPD patients (P < 0.05, FWE corrected). Abbreviations: TBSS, tract-based spatial statistics; COPD, chronic obstructive pulmonary disease; NCs, normal controls; WM, white matter; MD, mean diffusivity; AD, axial diffusivity; and RD, radial diffusivity