MRI肺与肝脏信号强度比值评估胎儿肺发育不良的价值

目的分析在泌尿系统畸形伴发的肺发育不良胎儿中肺信号强度降低的诊断价值。方法根据产前核磁共振成像诊断结果,33例孕20~34周的胎儿按照不同病变分为3组(单侧泌尿系统畸形组、双侧泌尿系统畸形组和其他畸形组),计算并比较各组肺与肝脏信号强度比值。结果双侧泌尿系统畸形胎儿的肺与肝脏信号强度比值明显降低(P<0.01),而单侧病变者相对正常。结论中期妊娠后,胎儿肺与肝脏信号强度比值降低可以高度提示泌尿系统畸形伴发的肺发育不良,尤其在双侧性病变中。

Assessment of fetal lung development by MRI signal intensity ratio of lung to liver

Objective To evaluate the monitoring and diagnostic potential of MRI in fetal lung development using lung signal intensity changes in fetuses with urinary anomalies. Methods Thirty-three fetuses with the gestational ages between 20 to 34 weeks were divided into three groups according to the MRI findings: unilateral urinary anomalies group,bilateral urinary anomalies group and other anomalies group.The lung-to-liver intensity ratio was calculated by means of region-of-interest analysis. Results Significangly lower ratios of lung-to-liver signal intensity were found in fetuses with bilateral urinary anomalies(P<0.01),while normal ones were observed in those with unilateral urinary anomalies. Conclusion After midtrimester pregnancy,low ratio of lung-to-liver signal intensity on MRI indicates pulmonary hypoplasia with urinary anomaly in fetus,especially in those with bilateral anomalies.