超声和MRI在胎儿中枢神经系统畸形诊断中的对比应用

Comparison of ultrasound and MRI in fetuses with central nervous system abnormalities

目的对比分析超声和MRI在胎儿中枢神经系统畸形诊断中的应用价值。方法在超声检出的529例中枢神经系统畸形胎儿中,有62例于超声检查后48h内接受产前MRI检查。此62例患者均经引产后尸检、尸体影像学检查或分娩后随访证实。将超声、MRI及随访结果进行对比分析。结果MRI与超声诊断结果一致39例(62.9%),MRI较超声提供更多诊断信息19例(30.6%),超声较MRI提供更多诊断信息3例(4.8%),MRI不能提供有效诊断信息1例(1.6%)。结论对于脑室扩张、颅内囊性病变、颅内团状异常回声、后颅窝异常及全前脑的评价MRI优于超声;而对于颈枕部肿块或囊性包块及开放性神经管缺陷的评价,MRI未见明显优势。超声检查仍是胎儿中枢神经系统畸形筛查的首选方法。在超声检查基础上进一步行MRI检查,有助于弥补超声检查的不足,甚至更正超声诊断,可作为产前胎儿检查的重要手段。

Objective To compare the diagnostic value of prenatal ultrasound with prenatal magnetic resonance imaging(MRI)in fetuses with central nervous system(CNS) abnormalities.MethodsIn 529 fetuses suspected as CNS abnormalities on ultrasound,62 fetuses received MRI examination within 48 hours after ultrasound,confirmed by autopsy,postmortem imaging or paediatric follow-up.The results of prenatal ultrasound and MRI were retrospectively analysed and were compared.Results The diagnoses obtained on ultrasonography and MRI were identical in 39(62.9%) fetuses.MRI provided more accurate informations than those of ultrasonography in 19 fetuses(30.6%),but less accurate in three fetuses(4.8%).MRI did not provide useful information in one fetus(1.6%).Conclusions MRI is superior to ultrasonography in the assessment of ventriculomegaly,intracranial cyst,intracranial abnormal echoic masses,posterior fossa abnormalities,and holoprosencephaly,but is not superior in the assessment of occipital masses or cysts,and open neural tube defects.Ultrasound may be still the first method for screening fetuses with CNS abnormalities.Based on ultrasound findings,prenatal MRI is a valuable complement to sonography in difficult cases,which can conform,complete and even correct ultrasonic diagnosis.