超声和核磁共振成像在胎儿脑中线结构检查中的对比研究

目的前瞻性地探讨和比较超声和核磁共振成像(MRI)在胎儿脑中线结构产前诊断中的应用价值。方法对32例胎儿的中枢神经系统(CNS)进行超声和MRI检查,所有胎儿随访至出生后或引产病检证实,并将两种检查的结果与随访结果进行对比分析。结果在产前CNS超声检查有异常发现的20例胎儿(其中涉及脑中线结构18例)中,MRI诊断正常12例,胎儿均足月生产无特殊;MRI诊断异常8例,行引产且胎儿尸检均证实异常。在胎儿脑中线结构检查中:超声诊断符合率93.8%,敏感性100%,特异性87.5%,阳性预测值88.9%,阴性预测值100%;MRI检查与最终结果均符合,诊断符合率100%,敏感性和特异性均为100%,明确和修正超声结果共计4例。结论超声是产前胎儿CNS检查的首选,当超声检查怀疑胎儿脑中线结构发育异常时,MRI是重要的补充。

Comparative Study of Ultrasonography and Magnetic Resonance Imaging in Midline Structures of Fetal Brain

Objective To evaluate the accuracy of ultrasonography(US) and magnetic resonance imaging(MRI) in midline structures of fetal brain.Methods Thirty-two fetuses underwent US and MRI examinatiom.Imagings acquired from US and MRI were analysed,the results were compared with the final outcomes which were obtained after fetal birth or pathological study after induction of labor.Results There were 20 cases found abnormal in prenatal CNS ultrasonography(18 cases involving midline structures).Among these 20 cases,12 cases were normal in MRI and the fetuses were born in full-term without special problem,8 cases were abnormal in MRI and fetal autopsy confirmed their abnormalities.Diagnostic accuracy rate of US was 93.8%,sensitivity was 100%,specificity was 87.5%,positive predictive value was 88.9%,negatvie predictive value was 100%.Diagnostic accuracy rate of MRI was 100%,modifying the US results in 4 cases.Conclusion US and MRI examinations are important in fetal central nervous system.US could be the first line examination,and MRI is an important supplement because of the high diagnostic accuracy,especially in the image study of midline structures of fetal brain.