Structural improvement of gray and white matter tissue has been associated with abstinence. Pfefferbaum et al. (1995) found a trend for increases in anterior cortical gray matter volumes after 20 days of sobriety, and Agartz et al. (2003) reported whole-brain increases in white matter volumes and corresponding decreases in CSF after one month of abstinence. Recovery of white matter microstructure has been demonstrated in longitudinal studies, with improvements in fractional anisotropy (a measure of microscopic abnormalities in axons) in the corpus callosum after one year of abstinence (Alhassoon et al., 2012) and decreases in mean radial diffusivity (a measure related to axonal demyelination) after only one month of sobriety, suggesting recovery of axonal integrity (Gazdzinski et al., 2010b). However, Monnig et al. (2012) reported persistent widespread fractional anisotropy deficits in bilateral parietal regions after a year of abstinence. Another marker for detecting reversal of global alcoholism-related brain damage that remains understudied is cerebral perfusion. The few studies examining perfusion improvements using arterial spin labeling MRI have yielded conflicting results. Mon et al. (2009) reported improvement of frontal and parietal gray
