正常儿童和青少年胼胝体发育及其性别差异的MRI观察

Development of corpus callosum with emphasis on sex difference:an MRI study

目的：探讨正常儿童和青少年发育过程中胼胝体的变化规律及其性别差异。方法：在微型计算机e-film2.0工作站中选取81名正常儿童和青少年颅脑正中矢状面MRI扫描图像,导入Adobe Photoshop10.0后,测量端脑和胼胝体及其亚区的面积。并对胼胝体发育的形态学规律及性别差异进行统计分析。结果：81名正常儿童和青少年胼胝体各亚区及总面积均与年龄存在直线相关关系（P〈0.05～P〈0.01）;男性和女性胼胝体Ⅰ区面积与年龄均无相关关系（P〉0.05）,而胼胝体其他各区及总面积与年龄均有相关关系（P〈0.05～P〈0.01）。两性胼胝体总面积及Ⅰ区、Ⅳ区和Ⅵ区面积差异均有统计学意义（P〈0.05～P〈0.01）,但校正脑体积后差异均无统计学意义（P〉0.05）。结论：在儿童和青少年发育期,随年龄增长胼胝体各亚区面积同步增大。1～18岁年龄段胼胝体的性别差异可能是由脑体积在两性的系统差异所致。

Objective：To investigate the regularity of callosal development in children and adolescent and its sex difference.Methods：The midsagittal images of 81 normal children and adolescent were selected in e-film workstation and then imported to the Photoshop.The area of the cerebrum and the corpus callosum were measured in Adobe Photoshop 10.0.Pearson correlation analysis and test were adopted to analyze the development of corpus callosum and the sex difference.Results：In the total samples,significant linear correlation was observed between the corpus callosum/all the subregions and the age（P〈0.05-P〈0.01） ;when the analyses were performed separately for males and females,all subregions still linearly correlated with the age except areaⅠ（P〈0.05）.Although significant sexual difference was found in the total callosal area,as well as in the areaⅠ,Ⅳ and Ⅵ（P〈0.05-P〈0.01）,the difference was not statistically significant（P〉0.05） after the cerebral volume was corrected.Conclusions：In normal children and adolescent,the callosal area increases with the age,and all the subregions increase simultaneously.Sex difference of callosal area may be better explained by an underlying effect of cerebral size.