Evaluation of the development on the preterm and term neonatal brain white matter based on metrics derived from diffusion tensor imaging / 西安交通大学学报(医学版)

ABSTRACT

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 enrolled 66 neonates,consisting of 33 preterm(21 males and 12 females;gestational age30.143-36.286 weeks)and 33 full-term neonates(22 males and 11 females;gestational age37.000 -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 Duboisfiber 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 fronto-occipital 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.