超声OmniView技术联合VCI技术测量正常胎儿脑干-小脑幕夹角和脑干-小脑蚓部夹角

Ultrasonic Omni View technology combined with VCI technology in evaluation of fetal brainstem-vermis angle and brainstem-tentorium angle

目的:测量正常胎儿脑干-小脑蚓部夹角(BV角)和脑干-小脑幕夹角(BT角),定量评估脑干上方小脑蚓部旋转角度和小脑幕插入角度,并检测上述参数测量的可重复性,探讨其与孕周的相关性。方法:应用三维超声自由解剖切面(Omni View)技术联合三维超声容积对比成像(VCI)技术获取216胎孕20~37周正常胎儿的小脑蚓部正中矢状切面图像,测量BV角与BT角;并进行重复性检验,分析其与孕周相关性。结果:216胎正常胎儿的BV角的正常范围为2.50°~18.05°,BT角的正常值范围为20.9°~43.2°;BV角与BT角测量的可重复性较好(组内相关系数(ICC)均>0.9),且两者与孕周均无相关(r=-0.31、0.36,P均>0.05)。结论:BV角和BT角作为定量衡量脑干上方小脑蚓部旋转角度和小脑幕插入角度指标,操作简单,可重复性强;计算两者的正常值范围可为鉴别诊断胎儿颅后窝池畸形提供帮助。

Objective:To quantitatively evaluate the normal rotation of the cerebellar vermis and normal tentorium insertion over the brainstem,using two novel measurements:the brainstem-vermis angle(BV angle)and brainstem-tentorium angle(BT angle).We also aimed to detect the reproducibility of these measurements and explore its correlation with gestational weeks.Method:A total 216 normally developing fetuses were examined prospectively at 20~37 weeks gestation.3D mid-sagittal planes were obtained with VCI and OmniView technology,and the BV angle and BT angle were measured in this section.Then intra-observer and inter-observer variations were calculated,and the relationship between BV angle and BT angle and gestational weeks were analyzed.Results:BV angle and BT angle in these normally developing fetuses ranged from 2.50°~18.05°and 20.9°~43.2°,respectively.The repeatability was good for both measurements(ICC>0.9).The estimated BV and BT angles had no relationship with gestational weeks(r=-0.31,0.36,both P>0.05).Conclusion:The BV and BT angle may be helpful in differentiating fetal posterior fossa malformation,giving a standardized and reproducible measurement of normal rota-tion of cerebellar vermis and normal tentorium insertion over the brainstem.