Quantitative evaluation of normal fetal posterior fossa anatomy using transabdominal three-dimensional ultrasound / 中华超声影像学杂志

ABSTRACT

Objective:To analyze the consistency and repeatability for quantitative evaluation of normal fetal posterior fossa anatomy using transabdominal three-dimensional ultrasound, and assess the clinical value.Methods:The midsagittal planes of fetal brain from 127 normal singleton fetuses with 22-34 weeks of gestation were obtained using transabdominal three-dimensional ultrasound between May, 2020 and May, 2021. The quantitative three-dimensional indicators were measured by two observers, then were measured twice by one of the two observers. The double blind was performed in course of measuring procedures. The intraobserver and interobserver agreements were evaluated. The relationships between three-dimensional indicators and gestational age were analyzed.Results:The quantitative three-dimensional indicators expressing the size of vermis, including area, perimeter, suprainferior diameter and anteroposterior diameter, had positive correlations with advanced gestational age ( r=0.934, 0.936, 0.920, 0.879; all P<0.001). The intra- and interobserver reproducibilities of measurements were very good with all intraclass correlation coefficients >0.80 (all P<0.001). Brainstem-vermis (BV) angle and Brainstem-tentorium (BT) angle had negative and positive correlations with advanced gestational age respectively ( r=-0.317, 0.366; both P<0.001). The intra-and interobserver reproducibilities of measurements were moderate or poor. Conclusions:The quantitative three-dimensional indicators describing the size of vermis are worthy of clinical application for evaluation of fetal posterior fossa owing to the excellent reproducibility and simple and feasible method of measurement. BV angle and BT angle are not applicable for junior physicians due to the poor reproducibility of measurement.