神经突起方向离散度和密度成像定量评估肝豆状核变性患者脑核团微结构改变

目的 观察神经突起方向离散度与密度成像（NODDI）定量分析肝豆状核变性（WD）基底核及丘脑核团微结构改变的价值，并评估NODDI对WD的诊断效能。方法 收集27例WD患者（WD组）及性别、年龄与之匹配的健康志愿者26名（对照组）行MR扫描，采用NODDI后处理方法，获得双侧尾状核、壳核、苍白球、丘脑的NODDI参数，包括神经突内体积分数（Vic）、神经突方向离散度（ODI）和脑脊液体积分数（Viso），比较两组间差异；分析各参数与临床Young评分的相关性，并采用随机森林模型评估各参数的相对重要性及对WD的诊断效能。结果 WD组双侧尾状核、壳核、苍白球的Vic值和ODI值均低于对照组，而Viso值高于对照组（P均<0.05）；与对照组比较，丘脑的Vic值降低而Viso值升高（P均<0.05），ODI值差异无统计学意义（P=0.055）。WD患者双侧尾状核、壳核、苍白球的Vic值和ODI值与临床Young评分呈负相关，壳核、苍白球的Viso值与临床评分呈正相关。采用随机森林模型，NODDI预测WD的准确率为96.23%，ROC曲线下面积为0.96。结论 NODDI可有效评估WD患者脑部铜沉积所致微观结构和代谢变化，有望用于检测WD患者脑深部核团结构改变，并评估其病情进展。

Quantitative evaluation of microstructural changes of brain nuclei in Wilson's disease with neurite orientation dispersion and density imaging

Objective To investigate the value of neurite orientation dispersion and density imaging (NODDI) in quantitative evaluation of the microstructural changes in basal ganglia and thalamus in Wilson''s disease (WD) patients, and to assess the diagnostic efficacy of NODDI. Methods Totally 27 WD patients (WD group) and 26 age-and sex-matched controls (control group) were enrolled. All subjects underwent MR scanning with NODDI. Parameters of NODDI, including intracellular volume fraction (Vic), orientation dispersion index (ODI) and isotropic volume fraction (Viso) of bilateral caudate nucleus, globus pallidus, putamen and thalamus were compared between the 2 groups. Correlation analysis was performed between each parameter of NODDI and clinical Young scores. Random Forest model was used to assess the relative importance of each parameter and to evaluate the diagnostic efficacy. Results The Vic and ODI of bilateral caudate nucleus, globus pallidus and putamen in WD patients were significantly lower than those in normal controls (all P<0.05), while Viso was significantly higher than that in normal controls (all P<0.05). The Vic of bilateral thalamus was lower, while Viso was higher in WD patients than those in normal controls (all P<0.05), and ODI had no significant difference between the 2 groups (P=0.055). In WD patients, Vic and ODI of bilateral caudate nucleus, globus pallidus and putamen were negatively correlated with clinical Young scores. Viso of globus pallidus and putamen were positively correlated with clinical scores. The prediction accuracy of NODDI was 96.23%, and the area under ROC curve was 0.96. Conclusion NODDI can effectively evaluate changes in microstructures and metabolism during copper deposition in WD patients, and it may be useful in detecting changes of brain deep nuclei and assessing the progression of WD.