三维超声观察正常胎儿额骨和额缝的变化规律

摘要

目的 运用三维超声观察9至32孕周正常胎儿的额骨和额缝的变化规律.方法 观察150例9至32孕周胎儿的额骨和额缝,分9～13孕周、14～16孕周、17～24孕周、25～28孕周和29～32孕周5个时段,每一时段各30例.运用经腹或经阴道二维扫查胎儿头面部全貌,用经腹或经阴道三维超声获取胎儿整个颅骨的容积数据,处理容积数据直至获得清晰胎儿面部的图像,观察分析不同孕周胎儿的额骨高度和额缝角度、宽度的变化规律.结果 在第9孕周,胎儿两侧额骨眶上部位的中点分别出现一个小骨化中心,至第11孕周时额骨像两道稠密的眉毛,从第13孕周至24孕周,双侧额骨高度随孕周逐渐增高,额缝的宽度随孕周逐渐缩小,双侧额骨逐步向中线汇合勾绘出额缝.额骨之间的缝隙在第16孕周左右从鼻骨区开始闭合,在28孕周向前囟门延伸,到第32孕周从鼻骨区至前囟门额缝明显闭合.结论 胎儿额骨的骨化和额缝的形成及闭合是有规律的,运用三维超声可以直观观察胎儿额骨和额缝的形成和发展过程,从而为临床早期诊断胎儿颅骨异常提供重要信息.%Objective To visualize the growth rhythm of frontal bone and metopic suture in normal fetuses,gestational weeks between 9 and 32,with use of three-dimensional ultrasound.Methods Visualizations of frontal bone and metopic suture were performed in 150 pregnant women,gestational weeks between 9 and 32, among which 30 cases was 9-13 gestational weeks, 30 cases 14 ～ 16 gestational weeks, 30 cases 17 ～ 24 gestational weeks, 30 cases 25 ～ 28 gestational weeks,and 30 cases 29 ～ 32 gestational weeks,respectively.Scan fetal heads and faces by 2D u ltrasonography,obtain volumes of the whole fetal skull by 3D ultrasonography,then analyze the growth rhythm of fetal frontal bone's height and metopic suture's width in different gestational weeks.Results At the ninth gestational week,the first ossification center appeared at frontal bone supraorbit centers.On the 11th gestational week, frontal bone looked like dense eyebrow.During 13-24 gestational weeks,fetal bilateral frontal bone gradually converged and metopic suture was delineated.The frontal bone's height is bigger with the longer gestational weeks, but the metopic suture's width is smaller.The suture between frontal bones began to fuse from nasal bone area at the 16th gestational week, followed by extension of suture to anterior fontanelle,and suture between nasal bone area and anterior fontanelle clearly occluded on the 32nd gestational week.Conclusions The sclerotization of fetal frontal bone and metopic suture development show a growth rhythm and three-dimensional ultrasound plays an nimportant role in the visualization of frontal bone,metopic suture development,and growth process,and may provide important data to clinical early diagnosis of anomalous skull.