Diffusion tensor imaging (DTI) is an MRI technique that can characterize tissue microstructure such as the principle direction of axonal fibers based on restricted diffusion of water molecules in tissue (Nixon et al., 2014). DTI has been used, albeit limitedly, to examine SG differences in AUD. For example, abstinent men with AUD had lower fractional anisotropy in corpus callosum, superior longitudinal fasciculus, and the arcuate fasciculus plus extreme capsule (FA; mean=0.68, 0.44, 0.43, respectively) compared to same-sex controls (mean=0.73, 0.47. 0.47, respectively), whereas abstinent women with AUD had higher FA (mean=0.72, 0.50, 0.49, respectively) in the same regions compared to same-sex controls (mean=0.69, 0.45, 0.45, respectively) (Sawyer et al., 2018). Findings were similar in the medial forebrain bundle, a white matter pathway connecting the VTA to the NAcc; abstinent men with AUD had lower FA (mean=0.54 vs. 0.62) and higher radial diffusivity (RD; mean=0.53 vs. 0.44) compared to same-sex controls, whereas abstinent women with AUD had higher FA (mean=0.58 vs. 0.55) and lower RD (mean=0.47 vs. 0.50) compared to same-sex controls (Rivas-Grajales et al., 2018). These findings suggest sexual dimorphism
