Quantification of liver herniation in fetuses with isolated congenital diaphragmatic hernia using two-dimensional ultrasonography.
[congenital diaphragmatic hernia]
To describe a method of quantifying the amount of liver herniation in fetuses with isolated congenital diaphragmatic hernia using two-dimensional ulrasonography (2DUS) and to correlate this finding with outcome.Ultrasound images were reviewed from 77 consecutive fetuses who presented with isolated CDH between January 2004 and July 2012. The liver herniation area and the thorax area were measured in a cross section of the fetal chest on a 4-chamber heart view (the same established section used to measure the lung-to-head ratio, LHR), and the ultrasound liver-to-thorax ratio (US-LiTR) was calculated by dividing the liver herniation area to the thorax area. The US-LiTR was compared to outcome (survival at 6 months of life and need for ECMO). In addition, the US-LiTR was compared to the MRI-derived liver-to-thorax ratio (MRI-LiTR) and percentage of liver herniation (MRI-%LH).The overall neonatal mortality was 20.7% (n = 16/77). ECMO was needed in 35.5% (n = 27/76) of newborns with a survival rate of 51%. The US-LiTR was associated statistically with mortality (p < 0.01) and with the need for ECMO (p < 0.01). Good correlations were observed between the US-LiTR and MRI-LiTR (r = 0.87; p < 0.01) and US-LiTR and MRI-%LH (r = 0.90; p < 0.01). Based on the ROC curve analysis, all three parameters had similar accuracy in predicting mortality (US-LiTR - AUC: 0.78, 95% CI: 0.65-0.92, p < 0.01; MRI-LiTR -AUC: 0.77, 95% CI: 0.63-0.90, p < 0.01 and,MRI-%LH - AUC: 0.79, 95% CI: 0.65-0.92, p < 0.01 respectively) as well as the need for ECMO (US-LiTR - AUC: 0.72, 95% CI: 0.60-0.84, p < 0.01; MRI-LiTR - AUC: 0.73, 95% CI: 0.60-0.85, p < 0.01 and MRI-%LH - AUC: 0.77, 95% CI: 0.64-0.89, p < 0.01, respectively).2DUS measurement of the amount of liver herniation in fetuses with isolated CDH is feasible and demonstrates an outcome predicting accuracy similar to MRI.
