Conclusion Alter midtrimester pregnancy, low ratio of lung-to-liver signal intensity no MRI indicates pulmonary hypoplasia with urinary anomaly in fetus, especially in those with bilateral anomalies.

• 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。