Fetal brainstem-vermis angle and brainstem-tentorium angle measured with three-dimensional ultrasonography and its application in mega cisterna magna / 中华超声影像学杂志

ABSTRACT

Objective To establish the ranges of normal reference values of fetal brainstem-vermis angle (BVA)and brainstem-tentorium angle (BTA)in normal fetuses at different gestational weeks,and to evaluate their clinical values in the diagnosis of mega cisterna magna.Methods Totally 320 normal singleton fetuses between 1 8 and 40 weeks of gestation were enrolled in this study.Three-dimensional ultrasound (3DUS)with volume contrast imaging (VCI)was used to measure their BVA and BTA,the correlations of BVA and BTA with gestational age were analyzed.The BVA and BTA of 24 fetuses with mega cisterna magna were also measured and were compared with those of the normal fetuses.Results In these normal fetuses,the BVA and BTA showed no correlations with gestational age (r=-0.05,0.04,both P >0.05);the ranges of normal reference values of BVA and BTA were 2.23°-19.30°and 18.53°-48.13°, respectively.The BVA and BTA of 24 fetuses with mega cisterna magna were 4.23°-17.42°and 20.41°-40.89°,respectively,which were not significantly different from those of normal fetuses (t =-0.55,0.92, both P >0.05).Conclusions 3DUS with VCI is feasible for measuring the BVA and BTA of fetuses,and the measured values can be used as the reference standards for BVA and BTA measurement in China.