全面性发育迟缓患儿大脑白质纤维束微结构异常的扩散峰度成像研究

Diffusion kurtosis imaging reveals microstructural abnormalities in cerebral white matter fiber tracts in children with global developmental delay

目的使用扩散峰度成像(diffusion kurtosis imaging,DKI)评估全面性发育迟缓(global developmental delay,GDD)患儿大脑白质纤维束微结构的改变。材料与方法这项前瞻性研究纳入了37例GDD儿童作为试验组和32例性别、年龄相匹配的健康儿童作为对照组。对所有参与者进行了DKI序列扫描,经过后处理得到扩散张量和峰度张量参数。使用基于束的空间统计学方法(tract-based spatial statistics,TBSS)比较了这些参数在两组之间的差异,并将组间有显著差异纤维束内的参数值与GDD儿童的神经发育得分进行Spearman相关分析。结果与对照组相比,GDD组右侧皮质脊髓束和右侧丘脑前辐射的平均扩散率(mean diffusivity,MD)均显著升高(P均<0.05);双侧丘脑前辐射、双侧皮质脊髓束和右侧上纵束的径向扩散系数(radial diffusivity,RD)也显著升高(P均<0.05)。此外,GDD组的径向峰度(radial kurtosis,RK)则显著降低(P均<0.05),包括双侧丘脑前辐射、双侧皮质脊髓束、双侧下额枕束、双侧上纵束、双侧下纵束、小钳、左侧钩状束和右侧扣带回。相关性分析发现,左侧下纵束和左侧钩状束的平均RK值与适应性行为得分呈正相关(r=0.349、0.486,P均<0.05);左侧钩状束的平均RK值与精细动作得分和个人-社交行为得分均呈正相关(r=0.365、0.590,P均<0.05)。结论DKI技术能够检测到GDD儿童大脑白质纤维束微结构的异常,为探索GDD潜在病理机制提供了有用的价值。

Objective:Diffusion kurtosis imaging(DKI)was employed to evaluate microstructural changes in the white matter fiber tracts of the brain in children with global developmental delay(GDD).Materials and Methods:This prospective study included 37 children with GDD in the experimental group and 32 age-and gender-matched healthy children in the control group.All participants underwent DKI sequence scanning,and diffusion tensor and kurtosis tensor parameters were obtained following post-processing.The parameters were compared between the two groups using tract-based spatial statistics(TBSS).Spearman correlation analysis was conducted between the parameter values within the fiber bundles showing significant intergroup differences and the neurodevelopmental scores of children with GDD.Results:Compared to the control group,the mean diffusivity(MD)of the right corticospinal tract and right anterior thalamic radiation were significantly increased in the GDD group(all P<0.05);the radial diffusivity(RD)of the bilateral anterior thalamic radiation,bilateral corticospinal tract,and right superior longitudinal fasciculus were also significantly increased(all P<0.05).Additionally,the radial kurtosis(RK)in the GDD group was significantly decreased(all P<0.05),including the bilateral anterior thalamic radiations,bilateral corticospinal tracts,bilateral inferior fronto-occipital fasciculi,bilateral superior longitudinal fasciculi,bilateral inferior longitudinal fasciculi,forceps minor,left uncinate fasciculus,and right cingulum.Correlation analysis revealed that the average RK values of the left inferior longitudinal fasciculus and left uncinate fasciculus were positively correlated with adaptive behavior scores(r=0.349,0.486,respectively;all P<0.05);the average RK value of the left uncinate fasciculus was positively correlated with fine motor and personal-social behavior scores(r=0.365,0.590,respectively;all P<0.05).Conclusions:The DKI technique can detect abnormalities in the microstructure of the white matter fiber bundles in children with GDD,providing useful insights into the potential pathophysiological mechanisms of GDD.