儿童脑白质髓鞘发育的磁共振弥散张量成像

摘要

目的 探讨健康儿童脑白质发育的磁共振弥散张量成像(DTI)参数变化特点及其规律.方法 收集健康儿童49名,按年龄分5组,即第1组≤1岁,第2组>1～3岁,第3组>3～6岁,第4组>6～12岁,第5组>12～18岁.各组均行脑部常规MRI和DTI扫描,对DTI原始数据进行处理获得各感兴趣区的DTI参数,并对所得数据进行统计分析.结果 不同性别儿童的双侧对称共10个部位的DTI参数无明显差别;各部位FA、RA值随年龄而递增,ADC、1-VR值则呈递减趋势;各部位间的DTI参数值的排序:FA、RA值为额叶<顶叶<半卵圆中心<枕叶<颞叶,1-VR值为颞叶<枕叶<半卵圆中心<顶叶<额叶.结论 儿童脑白质髓鞘发育中DTI各参数的变化具有一定的规律特点.%Objective To study the parameters of magnetic resonance diffusion tensor imaging coefficients during the development of white matter of brain in healthy children. Methods 49 healthy children were classified into five groups (≤1 year, ＞1-3 years, ＞3-6 years, ＞6-12 years, ＞12-18 years) and underwent conventional MRI (magnetic resonance imaging) and DTI (diffusion tensor imaging). Postprocessed the DTI source data to obtain the coefficients of each ROI (region of interest) and made an analysis statistically. Results There were no significant differences between the symmetric bilateral ROIs in DTI coefficients among the 10 locations selected in the brain. The FA (fractional anisotropy) and RA (relative anisotropy) values increased alongside with the increased ages while the tendency of the ADC (apparent diffusion coefficient) and 1-VR (volume ratio) values was opposite. The DTI coefficients of different locations ranged as follows: frontal lobe ＜ parietal lobe ＜ centrum ovale ＜ occipital lobe ＜temporal lobe (FA and RA values) , temporal lobe ＜ occipital lobe ＜ centrum ovale ＜ parietal lobe ＜frontal lobe (1-VR values). Conclusions The DTI coefficients showed certain characteristics during the myelinization of white matter of brain in children.