磁共振扩散张量成像多参量评估早产与足月新生儿脑白质发育  

Evaluation of the development on the preterm and term neonatal brain white matter based on metrics derived from diffusion tensor imaging

作　　者：李贤军[1] 刘哲[1] 孙亲利[1] 王苗苗[1] 刘聪聪 侯欣 刘黎明[2] 杨健[1] 

机构地区：[1]西安交通大学第一附属医院影像科,陕西西安710061 [2]西安交通大学第一附属医院儿保科,陕西西安710061

出　　处：《西安交通大学学报（医学版）》2018年第2期168-173,共6页Journal of Xi’an Jiaotong University（Medical Sciences）

基　　金：国家重点研发计划资助(No.2016YFC0100300);国家自然科学基金面上项目资助(No.81471631和81171317);教育部新世纪优秀人才支持计划(No.NCET-11-0438);陕西省自然科学基金青年项目资助(No.2017JQ8005);西安交通大学第一附属医院青年创新基金资助(No.2011YK.19;2017QN-09)~~

摘　　要：目的基于磁共振扩散张量成像(DTI)各参量的变化组合特点评估早产与足月新生儿脑白质不同区域的发育状态。方法纳入行常规磁共振成像未见异常的新生儿66例:早产儿33例(男21例,女12例;胎龄30.143~36.286周)、足月儿33例(男22例,女11例;胎龄37.000~41.429周)。行DTI扫描并获取参量:各向异性分数(FA)、平行扩散率(AD)以及垂直扩散率(RD)。运用Spearman秩相关分析分别评价早产儿与足月儿DTI参量与校正胎龄的相关性,并根据Dubois方法对脑白质发育状态进行评估:AD升高、RD降低、FA升高反映轴突排列有序化;AD降低、RD降低、FA不变或升高反映白质预髓鞘化;AD不变、RD降低、FA升高反映白质髓鞘化;采用Mann-Whitney U检验比较各参量的组间差异。结果根据Dubois的评估方法发现,内囊后肢、胼胝体在早产儿期已经处于髓鞘化阶段;大脑脚在足月儿期才开始髓鞘化;早产儿与足月儿放射冠上部、下额枕束以及外囊均处于预髓鞘化阶段。足月儿各感兴趣区域内FA高于早产儿(P<0.05),而除了大脑脚以外的其他区域足月儿的AD和RD均低于早产儿(P<0.05)。结论基于DTI多参量的发育变化和Dubois的方法可以量化评估新生儿脑白质发育状态,其符合髓鞘化和预髓鞘化阶段DTI参量变化特点,早产儿较足月儿的脑白质发育落后。Objective To explore developmental states on the preterm and term neonatal brain white matter based on the co-variation of metrics derived from diffusion tensor imaging(DTI).Methods This work enrolled66 neonates,consisting of 33 preterm(21 males and 12 females;gestational age:30.143-36.286 weeks)and 33 fullterm neonates(22 males and 11 females;gestational age:37.000-41.429 weeks).DTI derived metrics included axial diffusivity(AD),radial diffusivity(RD),and fractional anisotropy(FA).Spearman's rank correlation between metrics and postmenstrual age was analyzed in the preterm and term neonates.Developmental states were evaluated according to the method proposed by Dubois:fiber organization was associated with increased AD,decreased RD and increased FA;pre-myelination was related to decreased AD,decreased RD and unchanged/increased FA;myelination was revealed by unchanged AD,decreased RD and increased FA.Mann-Whitney U test was used to compare DTI metrics between the preterm and term neonates.Results According to the method proposed by Dubois,posterior limb of internal capsule and corpus callosum underwent myelination in the preterm-neonate period.Cerebral peduncle started myelination in the term-neonate period.Superior corona radiate,inferior frontooccipital fasciculus and external capsule underwent pre-myelination on preterm and term neonates.FA values were higher in term neonates than those in preterm neonates in all the selected regions(P<0.05).AD and RD values were lower in term neonates than those in preterm neonates in the selected regions except for cerebral peduncle(P<0.05).Conclusion Changes in DTI metrics and the method of Dubois can be used to quantitatively evaluate developmental states of the neonatal brain white matter.The changes coincided with DTI variations associated with pre-myelination and myelination.White matter development is delayed in preterm neonates compared with term neonates.

关 键 词：新生儿 脑白质 发育评估 扩散张量成像 早产儿 

分 类 号：R445.2[医药卫生—影像医学与核医学]