双胎妊娠胎儿脑异常的MR诊断价值(附6例报告及文献复习)

MR diagnostic value of fetal brain abnormalities in twin pregnancy(enclosed six cases and literature review)

目的通过对双胎妊娠胎儿脑部磁共振成像(magnetic resonance imaging,MRI)及超声影像比较分析,探讨MRI对双胎妊娠胎儿脑异常的初步评价。方法产前超声筛查303例胎儿异常或可疑异常中6例双胎妊娠孕妇,在1周内行MRI检查。结果单绒毛膜单羊膜囊1例,单绒毛膜双羊膜囊4例,双绒毛膜双羊膜囊1例。6例双胎妊娠中,1例胎儿MRI显示两侧脑室轻度扩张,超声示脑室轻度扩张;1例胎儿MRI显示两侧脑室重度扩张伴重度脑室周围白质软化(periventricular leukomalacia,PVL),超声示未见明显异常;1例胎儿MRI显示后颅窝池增宽,胼胝体压部发育不良,超声未见明显异常;1例胎儿单纯性后颅窝池增宽,超声未见明显异常;2例胎儿5、6脑室形成,超声未见明显异常;2例胎儿MRI显示胎儿失活,超声显示失活,减胎胎儿为术后4周复查。结论双胎妊娠胎儿脑异常超声漏诊率高,同时或邻近妊娠晚期行MRI检查,观察胎儿脑部发育情况具有重要产前价值。

Objective To study the preliminary evaluation of brain abnormality of twin pregnancy fetus by comparing and analyzing the magnetic resonance imaging(MRI)and ultrasonic imaging.Methods Prenatal ultrasound screening of six twin pregnant women in three hundred and three cases of fetal abnormality or suspicious abnormality,MRI was performed within one week.Results There were one case of single chorioamniotic sac,four cases of single chorioamniotic sac and one case of double chorioamniotic sac.Of the six twin pregnancies,one case showed mild expansion of bilateral ventricles on MRI and mild expansion of ventricles on ultrasound;one case showed severe expansion of bilateral ventricles with severe periventricular leukomalacia(PVL)on MRI and no obvious abnormality on ultrasound,one case showed enlargement of posterior fossa cistern and dysplasia of corpus callosum on MRI and no obvious abnormality on ultrasound,one case showed simple enlargement of posterior fossa cistern and no obvious abnormality on ultrasound,two cases showed formation of five and six ventricles,there was no obvious abnormality in ultrasound;two cases showed fetal deactivation on MRI,and two cases showed fetal deactivation on ultrasound,the reduced fetus was reviewed four weeks after operation.Conclusion The rate of missed diagnosis of fetal brain abnormality in twin pregnancy is high by ultrasound.At the same time,or near the end of pregnancy,MRI examination is of important prenatal value to observe the development of fetal brain.