磁共振弥散张量成像技术在新生儿脑白质发育中的研究

目的运用磁共振弥散张量成像(DTI)技术研究分析新生儿脑白质发育规律和特点。材料与方法本研究纳入38名新生儿,包括18例适于胎龄早产儿,20例正常出生体重足月儿,按胎龄分为3组,分别测量各兴趣区FA值进行分析。结果新生儿脑实质FA值无左右差异。外周白质FA值小于深部白质,在深部脑白质中,胼胝体压部FA值高于膝部,内囊后肢高于前肢,胼胝体压部高于内囊后肢;在外周脑白质中,半卵圆中心层面中部白质FA值最高,半卵圆中心前、后白质的FA值均无统计学差异(P0.05)。Ⅲ组各兴趣区FA值均高于Ⅰ组,且差异有统计学意义(P0.05),相邻胎龄组比较,只有部分兴趣区有统计学差异。结论 DTI技术在研究新生儿脑白质成熟方面具有重要价值,FA值可定量评估髓鞘发育。

Diffusion tensor imaging study of normal neonatal brain maturation

Objective:The purpose of this study was to investigate the developing status and characteristics of cerebral white matter during the neonatal period by using diffusion tensor imaging technique. Materials and Methods:In this study, 38 newborns were selected, including eighteen preterm infants (appropriate for gestational age) and twenty term infants (normal birth weight), they were divided into three groups according to their gestational age, fractional anisotropy obtained from each region of interest was analyzed. Results:The differences of FA values between left and right hemispheric white matter regions were no signiifcant statistically. FA values for the peripheral white matter regions were lower than the values for deep white matter structures,in the deep white matter, the splenium of corpus callosum showed larger FA than genu, and the anterior limb of internal capsule showed smaller FA than posterior limb of internal capsule, the FA values for the splenium were higher than the values for the posterior limb of internal capsule. Among peripheral white matter, FA in central white matter (the level of central semiovale) were the highest, no signiifcant differences were observed between anterior and posterior white matter (the level of central semiovale) (all P>0.05). FA values for all measured regions in groupⅢwere more than that values in groupⅠ, and the differences were signiifcant statistically (all P<0.05), comparison between adjacent groups, there were signiifcant statistically only in part of regions of interest. Conclusion:Diffusion tensor imaging technique is very usefull in the study of neonatal white matter maturation, FA value can assess myelin development quantitatively.