正常胎儿小脑蚓部发育MRI评价

摘要

目的 通过测量正常活体胎儿蚓部及毗邻结构各径线及角度数值,计算参考值范围,分析蚓部随胎龄的发育规律.材料与方法 搜集本院2011年1月至2017年2月间中、晚孕期胎儿头部MR图像856例进行回顾分析,选取正中矢状面分别测量蚓部前后径、上蚓高度、下蚓高度、蚓部面积,选取标准小脑横切面测量蚓部长度与后颅窝池深度的比值(蚓部/后颅窝池)、蚓部长度与第四脑室前后径的比值(蚓部/四脑室前后径)、小脑蚓部与脑干背侧切线之间的夹角(BVo)、小脑幕切迹与脑干背侧切线之间的夹角(BTo),观察蚓部发育情况并进行统计分析.结果 23～40周胎儿蚓部前后径、上/下蚓高度、面积、蚓部/后颅窝池、蚓部/四脑室前后径整体均与胎龄呈线性正相关,为直线增长趋势,其中正中矢状位前后径、蚓部面积与胎龄呈现的相关性最强,蚓部/四脑室前后径相关性最差.随着胎龄增长BV角总体呈现减小趋势,而BT角与胎龄变化无相关性(P>0.05).结论 胎儿MR可以可靠地描绘蚓部的解剖结构,依据规范参考数据,动态评价蚓部发育.%Objective: By measuring normal fetal cerebellar vermis, adjacent structure and the angle value, calculate reference range, analyze development of different gestational age. Materials and Methods: MR images of 856 normal fetal heads in the middle and late pregnancy (from January 2011 to February 2017) were collected, separately measure vermis diameter, superior/inferior vermis height, area, vermis/posterior cranial fossa, vermis/anterior posterior diameter of the four ventricle, BV°, BT° to observe the vermis development and statistical analysis. Results: The overall and gestational age showed a linear positive correlation for linear growth, which the median sagittal anteroposterior diameter, vermis area and gestational age had the strongest correlation. Vermis/anterior posterior diameter of the four ventricle had the worst correlation. With the increase of gestational age, BV angle showed a decreasing trend, but BT was not correlated with the change of age. Conclusions: Fetal MR can reliably depict vermis of anatomical structure, dynamically evaluate the development of the vermis according to the normative reference data.