孕中晚期胎儿脑皮层折叠分级与孕龄相关性的MRI研究

Correlation between MRI grading of fetal cerebral cortical infolding and gestational age in the middle and late stages of pregnancy

目的基于MRI探讨孕中晚期胎儿脑皮层折叠分级与孕龄之间的相关性。方法横断面研究。纳入2017年5月—2024年2月在青岛大学附属泰安市中心医院进行MRI检查的89例正常单胎胎儿作为研究对象。孕妇年龄21~43(29.8±5.3)岁,孕龄25+1~35+6(31.2±2.8)周,胎儿均发育正常。根据胎儿脑皮层的折叠特征,将其折叠程度分为1~4级四个等级,并对每个胎儿的折叠等级进行评价和记录。利用描述性统计分析脑皮层折叠分级的孕龄分布情况,通过Spearman相关系数评估脑皮层折叠分级与孕龄之间的相关性。结果89例胎儿中,脑皮层1级折叠8例出现在孕25~27周,2级折叠21例出现在孕26~30周,3级折叠40例出现在孕29~34周,而4级折叠20例出现在孕32~35周。胎儿脑皮层折叠分级与孕龄呈高度正相关(r_(s)=0.92,P<0.001)。孕龄<26周的4例胎儿脑皮层折叠分级均为1级,孕龄≥28周的74例胎儿脑皮层折叠分级均≥2级,孕龄≥31周的51例胎儿脑皮层折叠分级均≥3级,孕龄≥35周的7例胎儿脑皮层折叠分级均为4级。结论孕中晚期胎儿脑皮层折叠分级随孕龄增加从低级向高级发展,两者间存在高度正相关关系;基于产前MRI的胎儿脑皮层折叠分级可作为评估脑沟回发育的重要指标。

Objective This study aimed to investigate the correlation between the grading of fetal cortical infolding and gestational age in the second and third trimesters on the basis of prenatal MRI.Methods A total of 89 normal singleton pregnant women who underwent MRI examination at the Affiliated Tai'an City Central Hospital of Qingdao University from May 2017 to February 2024 were included in this cross-sectional study.The maternal age ranged from 21 to 43(29.8±5.3)years,and the gestational age ranged from 25+1 to 35+6(31.2±2.8)weeks.All fetuses were developmentally normal.The degree of cortical infolding was classified into four grades(from grade 1 to grade 4)on the basis of its characteristics,and the infolding grade of each fetus was evaluated and recorded.Descriptive statistics was used to assess the distribution of cortical infolding grades across gestational ages,and the correlation between cortical infolding grades and gestational age was evaluated using Spearman's correlation coefficient.Results Among the 89 fetuses,grade 1 cortical infolding was observed in eight cases between 25 and 27 weeks of gestation,grade 2 in 21 cases between 26 and 30 weeks,grade 3 in 40 cases between 29 and 34 weeks,and grade 4 in 20 cases between 32 and 35 weeks.A highly positive correlation was found between fetal cortical infolding grade and gestational age(r_(s)=0.92,P<0.001).Fetuses with a gestational age of<26 weeks(4 cases)all had Grade 1 cortical infolding;those with a gestational age of≥28 weeks(74 cases)had Grade≥2 cortical infolding;fetuses with a gestational age of≥31 weeks(51 cases)had Grade≥3 cortical infolding;and those with a gestational age of≥35 weeks(7 cases)had Grade 4 cortical infolding.Conclusion The grading of fetal cortical infolding in the second and third trimesters develops from lower to higher grades with increasing gestational age,demonstrating a highly positive correlation between the two.The grading of fetal cortical infolding based on prenatal MRI can serve as an important indicator for assessing the development of sulci and gyri.