MRI calculation of lung volumes to predict outcome in fetuses with genitourinary abnormalities.

OBJECTIVE: The purpose of our study was to evaluate MRI total lung volumes (TLV) for predicting outcome in fetuses with genitourinary abnormalities and to compare lung volumes with the presence or absence of oligohydramnios.

MATERIALS AND METHODS: Fetuses with genitourinary abnormalities underwent blinded retrospective calculation of TLV. Distribution of the TLV-gestational age ratios for survivors and nonsurvivors were compared using the Wilcoxon's rank sum test. Lung volume calculation was compared with the presence or absence of oligohydramnios.

RESULTS: There were 21 survivor and 24 nonsurvivor outcomes based on neonatal discharge. TLV-gestational age ratios were significantly different between the survivor and nonsurvivor groups (p = 0.0001). No apparent difference was seen until after 26 weeks of gestation. TLV-gestational age ratios were equal to the presence or absence of oligohydramnios in predicting outcome after 26 weeks of gestation.

CONCLUSION: After 26 weeks' gestation, the prediction of outcome in fetal genitourinary abnormalities using the MRI TLV-gestational age ratio is comparable to the presence or absence of oligohydramnios.