中晚孕期胎脑与胎盘表观扩散系数比值和孕周的相关性研究

Correlation between Gestational Age and Apparent Diffusion Coefficient Ratio of Fetal Brain to Placenta in Middle and Late Pregnancy

目的 探讨中晚孕期胎儿不同脑区与胎盘的ADC比值和孕周的相关性。方法 回顾性分析本院MRI检查的单胎妊娠孕妇98例,MRI检查未见明显胎儿颅脑异常。孕妇年龄19~40岁,平均(28.74±4.46)岁。孕周21~38周,平均(29.73±3.87)周。测量胎盘、脑干、双侧小脑半球、基底核、丘脑及双侧各脑叶深部白质的ADC值,分析胎脑各区域ADC值与胎盘ADC值的相关性;并计算出胎脑各区域与胎盘ADC比值,分析该比值和孕周的相关性。结果 左右两侧大脑半球及小脑半球对称部位ADC值无统计学差异(P>0.05)。幕上深部白质的平均ADC值高于小脑半球、基底核、丘脑、脑干。胎脑各区域ADC值与胎盘ADC值无相关性(P>0.05)。额叶深部白质与胎盘ADC比值(F/P)和孕周呈显著正相关(r=0.272,P<0.01);丘脑与胎盘ADC比值(Th/P)、脑干与胎盘ADC比值(S/P)、小脑与胎盘ADC比值(C/P)和孕周呈显著负相关(r值分别为-0.301、-0.399、-0.445,P值均<0.01)。结论 中晚孕期正常胎儿脑组织与胎盘ADC比值随胎儿孕周的增加有一定变化规律,可为产前诊断及预后提供一定的参考信息。

Objective To investigate the correlation between gestational age(GA)and ADC ratio of fetal brain to pla-centain the middle and late pregnancy.Methods A total of 98 fetuses performed fetal MRI from 2017 to 2021 were retro-spectively collected in Affiliated Hospital of Xuzhou Medical University.All fetuses found no central nervous system abnor-malities,which was confirmed by MRI.The age of pregnant women ranged from 19 to 40 years,with an average of(28.74±4.46)years.Gestational weeks ranged from 21 to 38 weeks,with an average of(29.73±3.87)weeks.The ADC values of placenta,brainstem,bilateral cerebellar hemispheres,basal ganglia,thalamus and deep white matter of bilateral cerebral lobes were measured on MRI images.The ADC ratio of fetal brain to placenta were calculated,and the correlation between the ratio values and GA were analyzed.Results There was no significant difference in ADC values between symmetrical parts of bilateral cerebral hemisphere and cerebellar hemisphere(P>0.05).The average ADC value of supratentorial deep white matter was higher than that of cerebellum,hemisphere,basal nucleus,thalamus and brainstem.There was no correla-tion between ADC value of fetal brain and that of placental(P>O.05).The F/P value was positively correlated with GA(r=0.272,P<0.01);The Th/P value,S/P value and C/P value were negatively correlated with GA(r values were-0.301,-0.399 and-0.445,respectively,P<0.01).Conclusion The ADC ratio of normal fetal brain tissue to placen-ta in the middle and late pregnancy are related with fetal GA,which can provide some information for prenatal diagnosis and prognosis.