磁共振弥散张量成像定量评价生长受限胎儿脑白质发育的研究

目的探讨胎儿生长受限(FGR)是否对胎儿脑白质发育造成不良影响。方法选择28例足月小于胎龄儿(SGA)为研究对象,15例足月适于胎龄儿(AGA)为对照组,均行头颅磁共振及磁共振弥散张量成像(DTI),将颅脑白质分为122个脑区,比较两组不同脑区各向异性分数(FA)、平均弥散系数(MD)、平行弥散系数(λ_//)及垂直弥散系数(λ_⊥)的差异。结果 SGA儿16个脑区的FA值低于对照组(P0.01);7个脑区的MD值高于对照组(P0.05);8个脑区的λ_//值高于对照组(P0.05);16个脑区的λ_⊥值高于对照组(P0.05)。结论宫内生长受限可导致脑白质纤维束成熟度及完整性异常。

Quantitative evaluation of white matter development in fetus with growth restriction by diffusion tensor imaging

Objective To investigate whether fetal growth restriction (FGR) has an adverse effect on white matter development. Methods A total of 28 full-term small for gestational age (SGA) infants were enrolled as study subjects and 15 full-term appropriate for gestational age infants were enrolled as control group. Conventional head magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) were performed for all infants. The white matter was divided into 122 regions. The two groups were compared in terms of fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity of different brain regions. Results Compared with the control group, the SGA group had a significantly lower fractional anisotropy in 16 brain regions (P<0.01), a significantly higher mean diffusivity in 7 brain regions (P<0.05), a significantly higher axial diffusivity in 8 brain regions (P<0.05), and a significantly higher radial diffusivity in 16 brain regions (P<0.05). Conclusions FGR may cause abnormalities in the maturity and integrity of white matter fiber tracts.