正常胎儿小脑蚓部发育MRI评价

MR evaluation of normal fetal cerebellar vermis development

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.