Application of transabdominal two-dimensional ultrasonography in detection of cerebellar vermis in fetus

Abstract

Objective To establish the normal data of the fetal cerebellar hemispheres and vermis, analyse its relationship with different gestational age, and evaluate its clinical significance in the diagnosis of the cerebellar vermis abnormalities. Methods Totally 390 normal singleton fetuses between 18 and 40 gestational weeks (GW) were enrolled in this study, two-dimensional ultrasound(2DUS) technology was used to measure cerebellar width(CW), cerebellar height(CH), vermian width(VW) and vermian height(VH), then the correlation between all measurements and the gestational weeks was analyzed. Eighteen fetuses with mega cisterna magna and 6 fetuses with vermis hypoplasia were assessed and compared with the normal fetuses. Results In all healthy controls, CW, CH, VW, and VH increased with GW (R2=0.952, 0.712, 0.905, 0.894, respectively). VW/CW decreased with GW increasing (R2=0.659). VH/CH had no relationship with GW (R2=0.007). VH/CH in normal fetuses was 0.76±0.04, VH/CH in fetuses with CM was 0.74±0.03, there was no significant difference between them(Z=-1.35, P=0.18); VH/CH in fetuses with hypoplasia was 0.58±0.04, and was smaller than that of healthy controls (Z=-4.22, P=0.001). Conclusions Evaluating fetal cerebellar vermis development by two-dimensional ultrasound is a kind of simple, fast and effective method. VH/CH is an important reference indicators and can be used for prenatal diagnosis of cerebellar vermis abnormalities. Key words: Ultrasonography, prenatal; Fetus; Cerebellum; Vermis hypoplasia