[The value of MR diffusion tensor imaging in assessing white matter changes in short-term methamphetamine withdrawal]

Objective: To explore the value of MRI diffusion tensor imaging (DTI) in the white matter changes of short-term methamphetamine (MA) abstinence. Methods: The data of DTI, demographics features, general information of addiction and impulsivity scale eleven (BIS-11) of 55 short-term MA addicts who were from Changsha, Zhuzhou and Yueyang compulsory detoxification centers in Hunan province, including 40 males and 15 females, aged 14-45 (37.24±7.31) years old, and 52 healthy controls, including 40 males and 12 females aged 18-59 (40.3±9.1) years were collected prospectively from August 2017 to December 2018. The differences of DTI indicators between the two groups were compared by tract-based spatial statistics (TBSS), and then the correlation between the different indicators and the age of first MA use, time of MA use, daily dose used, BIS-11 score were performed. Results: There were significant differences in BIS total score(P<0.001), BIS motivational impulsivity(P<0.001) and BIS attentional impulsivity(P=0.003) between MA group and healthy control group in short-term withdrawal. And compared with the healthy control group, the fractional anisotropy (FA) (0.58±0.02 vs 0.56±0.02,0.77±0.02 vs 0.75±0.04,0.79±0.04 vs 0.76±0.06; all P<0.05), axial diffusivity (AD) (0.57±0.01 vs 0.56±0.02,P=0.001) and mean diffusivity (MD) (0.66±0.02 vs 0.65±0.02,0.52±0.07 vs 0.51±0.06; both P<0.05)values in the MA group were all increased (P<0.05), but there was no significant difference in the radial diffusivity (RD) value (P>0.05). The white matter areas with increased FA value were located in the knee and body of corpus callosum, bilateral anterior corona radiata and left superior corona radiata; the areas with increased AD value were located in the knee, body and pressure of corpus callosum, bilateral anterior limb of internal capsule, posterior limb of internal capsule, anterior, superior and posterior corona radiata, external capsule and superior longitudinal fasciculus; and the areas with increased MD value were mainly located in the right superior longitudinal fasciculus, anterior and posterior limb of internal capsule. The corpus callosum, where there was a difference in FA between the two groups, was positively correlated with the daily dose of MA (r=0.301, P=0.026). Conclusion: MA addicted individuals with short-term withdrawal have white matter edema and damage, and the degree of corpus callosum damage is positively correlated with the daily dose of MA,which is helpful to understand the pathophysiological process of white matter damage in the nervous system and the potential mechanism of neuropsychiatric symptoms in short-term withdrawal MA addicted individuals.