扩散张量成像观察重度吸烟者脑白质微观结构完整性

目的 采用基于示踪空间统计分析的扩散张量成像（TBSS-DTI）观察重度吸烟者（HS）脑白质微观结构的完整性。方法 根据中文版尼古丁依赖量表（FTND）筛选34名HS（HS组）和年龄、性别及教育水平匹配的非吸烟志愿者（NS）34名（NS组），行TBSS-DTI采集，测量异常脑白质区扩散参数，包括轴向扩散系数（Da），径向扩散系数（Dr），平均扩散系数（MD）及FA，应用多元回归分析扩散参数与HS吸烟相关参数的相关性。结果 与NS组比较，HS组胼胝体左前部（包括胼胝体膝部和嘴体部）FA值降低。FA值降低脑区Da显著降低、Dr显著升高（P均<0.05）。胼胝体左前部Dr和MD与烟龄呈正相关（Dr：r=0.356，P=0.049；MD：r=0.405，P=0.024）。结论 HS胼胝体左前部白质微观结构完整性异常，并与烟龄相关，提示重度尼古丁依赖导致脑白质进行性退行性变。

Diffusion tensor imaging in observation on integrity of cerebral white matter microstructure in heavy smokers

Objective To explore the integrity of microstructure of cerebral white matter in heavy smokers (HS) with tract-based spatial statistics-DTI (TBSS-DTI). Methods Thirty-four HS were selected according to Chinese version of Fagerström test of nicotine dependence (FTND), while 34 non-smokers (NS) matched with age, sex and educational level were enrolled as controls. All HS and NS underwent TBSS-DTI, and then the parameters, including axial diffusivity (Da), radial diffusivity (Dr), mean diffusivity (MD) and fractional anisotropy (FA) were compared. The correlation between diffusion parameters and smoking-related parameters of HS was analyzed by using multiple regression analysis. Results Compared with NS, HS presented lower FA value in the left anterior corpus callosum (genu and rostral body). In the affected regions, FA reduction was accompanied with significant Da decrease and Dr increase (both P<0.05). Moreover, significant positive correlation was found between Dr or MD with smoking years (Dr: r=0.356, P=0.049; MD: r=0.405,P=0.024). Conclusion In HS, integrity of cerebral white matter microstructure in the anterior corpus callosum is abnormal and correlated with smoking years, indicating progressive degeneration of cerebral white matter with heavy nicotine dependence.