新生儿和婴幼儿脑髓鞘发育的DTI

Diffusion tensor imaging for neonatal and infantile brain myelination

目的:探讨平均扩散率(MD)和部分各向异性(FA)在新生儿和婴幼儿脑髓鞘发育过程中的变化规律。方法:将97例围产史正常、无器质性神经系统疾病的足月新生儿和婴幼儿按年龄段分为7组,行颅脑扩散张量成像(DTI)扫描,测量主要白质结构的MD值和FA值,分析其在不同脑区的差异及随年龄变化的规律。结果:脑各部位的MD值随着年龄的增长而减低(P<0.01),FA值随年龄的增长而增高(P<0.01)。脑同一部位的MD值和FA值在不同年龄段的变化速率有所不同,同一年龄段脑不同部位MD值和FA值的变化幅度不尽相同,不同部位的MD值和FA值也存在差异。结论:MD值和FA值相结合,能定量的分析髓鞘化进程,评估脑白质发育情况。

Objective：To discuss the changes of mean diffusivity（MD） and fractional anisotropy（FA） values in developing brain of normal neonates and infants.Methods：97 term neonates and infants were investigated by DTI.Their perinatal medical records and nervous system examinations were nothing remarkable.They were divided into 7 groups according to the age.MD/FA values in main white matter（WM） structures were analyzed.Results：Accompanied with the increase of age,MD values in the WM decreased（P〈0.01）,while FA values increased（P〈0.01）.The change rates of MD/FA values in the same region of the different age groups were different.The MD/FA values and their change ranges in different regions of the same age group were different too.Conclusion：MD/FA values can be used for analyzing myelination process quantitatively and evaluating brain WM development.