Regions showing lower fractional anisotropy (FA) values in methadone maintenance treatment (MMT) and normal control (NC).

Boldfaced tmax values represent clusters that passed the cluster based statistical criteria with t>3, corrected p2/s) multiplied by 10−6.*Significant differences (p≤0.05, Bonferroni-adjusted) with age, sex, education, and histories of smoking and alcohol consumption as covariates.Abbreviations: MNI, Montreal Neurological Institute; BA, Brodmann area.