Evangelou I E, du Plessis A J, Vezina G, Noeske R, Limperopoulos C
From the Divisions of Diagnostic Imaging and Radiology (I.E.E., G.V., C.L.) Departments of Pediatrics (I.E.E. A.J.D.P., G.V., C.L.) Radiology (I.E.E., G.V.), The George Washington University School of Medicine and Health Sciences, Washington, DC.
Fetal and Transitional Medicine (A.J.D.P., C.L.), Children's National Medical Center, Washington, DC Departments of Pediatrics (I.E.E. A.J.D.P., G.V., C.L.).
AJNR Am J Neuroradiol. 2016 Feb;37(2):360-6. doi: 10.3174/ajnr.A4512. Epub 2015 Sep 24.
(1)H-MRS provides a noninvasive way to study fetal brain maturation at the biochemical level. The purpose of this study was to characterize in vivo metabolic maturation in the healthy fetal brain during the second and third trimester using (1)H-MRS.
Healthy pregnant volunteers between 18 and 40 weeks gestational age underwent single voxel (1)H-MRS. MR spectra were retrospectively corrected for motion-induced artifacts and quantified using LCModel. Linear regression was used to examine the relationship between absolute metabolite concentrations and ratios of total NAA, Cr, and Cho to total Cho and total Cr and gestational age.
Two hundred four spectra were acquired from 129 pregnant women at mean gestational age of 30.63 ± 6 weeks. Total Cho remained relatively stable across the gestational age (r(2) = 0.04, P = .01). Both total Cr (r(2) = 0.60, P < .0001) as well as total NAA and total NAA to total Cho (r(2) = 0.58, P < .0001) increased significantly between 18 and 40 weeks, whereas total NAA to total Cr exhibited a slower increase (r(2) = 0.12, P < .0001). Total Cr to total Cho also increased (r(2) = 0.53, P < .0001), whereas total Cho to total Cr decreased (r(2) = 0.52, P < .0001) with gestational age. The cohort was also stratified into those that underwent MRS in the second and third trimesters and analyzed separately.
We characterized metabolic changes in the normal fetal brain during the second and third trimesters of pregnancy and derived normative metabolic indices. These reference values can be used to study metabolic maturation of the fetal brain in vivo.
（1）氢质子磁共振波谱（¹H-MRS）提供了一种在生化水平上研究胎儿脑成熟度的非侵入性方法。本研究的目的是使用¹H-MRS对妊娠中期和晚期健康胎儿脑内的体内代谢成熟情况进行特征描述。
对18至40孕周的健康孕妇志愿者进行单体素¹H-MRS检查。对磁共振波谱进行回顾性校正以去除运动诱导伪影，并使用LCModel进行定量分析。采用线性回归分析绝对代谢物浓度以及总NAA、Cr和Cho与总Cho和总Cr的比值与孕周之间的关系。
从129名平均孕周为30.63±6周的孕妇中采集了204个波谱。总Cho在整个孕周期间保持相对稳定（r² = 0.04，P = 0.01）。总Cr（r² = 0.60，P < 0.0001）以及总NAA和总NAA与总Cho的比值（r² = 0.58，P < 0.0001）在18至40周之间显著增加，而总NAA与总Cr的比值增加较慢（r² = 0.12，P < 0.0001）。总Cr与总Cho的比值也增加（r² = 0.53，P < 0.0001），而总Cho与总Cr的比值随孕周下降（r² = 0.52，P < 0.0001）。该队列还被分层为在妊娠中期和晚期接受MRS检查的人群并分别进行分析。
我们描述了妊娠中期和晚期正常胎儿脑内的代谢变化，并得出了正常代谢指标。这些参考值可用于研究胎儿脑内的代谢成熟情况。
