胎儿孤立性单侧侧脑室扩张对脑实质体积影响的MRI研究

MRI study of the effect of isolated unilateral ventriculomegaly on the volume of brain parenchyma

目的研究不同程度单侧侧脑室扩张对脑实质体积的影响并探讨其对胎儿诊疗的临床价值。方法收集经超声证实的孤立性单侧侧脑室扩张的胎儿,行胎儿颅脑1.5T MR扫描。测量扩张侧及正常侧的侧脑室宽度、相邻外侧脑实质厚度、侧脑室体积、大脑半球体积,并计算脑实质体积。每隔1月随访侧脑室宽度随孕周的变化情况。结果最终纳入研究的23~31孕周的孤立性单侧侧脑室扩张胎儿共49例,按扩张程度分为3组:轻度扩张组12例、中度扩张组27例、重度扩张组10例。对比研究结果如下:(1)3组病例的扩张侧与正常侧比较,扩张侧邻近脑实质厚度减小,脑实质体积未见明显差异;(2)3组病例间的扩张侧侧脑室宽度、体积及大脑半球体积均存在差异(P<0.05),扩张侧脑实质厚度及体积未见明显差异;(3)随访发现轻中度扩张组侧脑室宽度逐渐减小者占76%,重度扩张组流产率达80%。结论孤立性单侧侧脑室扩张对脑实质的体积没有影响,轻中度扩张胎儿预后好,这为侧脑室扩张胎儿的评估、预后和干预提供了重要影像学信息。

Objective To investigate the effect of fetal isolated unilateral ventriculomegaly on the volume of brain parenchyma and its clinical value in fetal diagnosis and treatment.Methods Isolated unilateral ventriculomegaly confirmed by ultrasound underwent fetal brain examination at 1.5T MRI.The width of lateral ventricle,the thickness of adjacent lateral brain parenchyma,the volume of lateral ventricle and the volume of cerebral hemisphere were measured on the dilated side and the normal side,and the volume of brain parenchyma was calculated.The changes of the width of lateral ventricle with gestational age were followed up at an interval of 1 month.Results A total of 49 fetuses with isolated unilateral ventricular dilatation at 23-31 gestational weeks were finally included in the study.They were divided into three groups according to the degree of dilatation:12 cases in the mild dilatation group,27 cases in the moderate dilatation group and 10 cases in the severe dilatation group.The results of comparative study were as follows:⑴Compared with the normal side,the thickness of adjacent brain parenchyma on the dilated side decreased,and the volume of brain parenchyma was no significant difference;⑵There were differences in the width and volume of the dilated lateral ventricle and the volume of the cerebral hemisphere among the three groups(P<0.05),and there was no significant difference in the thickness and volume of the brain parenchyma on the dilated side.⑶The follow-up showed that the width of lateral ventricle gradually decreased in 76%in the mild and moderate dilation groups,and the abortion rate in the severe dilation group was 80%.Conclusions Isolated unilateral lateral ventricular dilatation has no effect on the volume of brain parenchyma,and the prognosis of fetuses with mild to moderate dilatation is good,which provides important imaging information for the evaluation,prognosis and intervention of fetuses with lateral ventricular dilatation.