Standardization of Sonographic Lung-to-Head Ratio Measurements in Isolated Congenital Diaphragmatic Hernia: Impact on the Reproducibility and Efficacy to Predict Outcomes

J Ultrasound Med. 2015 Oct;34(10):1721-7. doi: 10.7863/ultra.15.14.11064. Epub 2015 Aug 25.


Objectives: The purpose of this study was to evaluate the impact of standardization of the lung-to-head ratio measurements in isolated congenital diaphragmatic hernia on prediction of neonatal outcomes and reproducibility.

Methods: We conducted a retrospective cohort study of 77 cases of isolated congenital diaphragmatic hernia managed in a single center between 2004 and 2012. We compared lung-to-head ratio measurements that were performed prospectively in our institution without standardization to standardized measurements performed according to a defined protocol.

Results: The standardized lung-to-head ratio measurements were statistically more accurate than the nonstandardized measurements for predicting neonatal mortality (area under the receiver operating characteristic curve, 0.85 versus 0.732; P = .003). After standardization, there were no statistical differences in accuracy between measurements regardless of whether we considered observed-to-expected values (P > .05). Standardization of the lung-to-head ratio did not improve prediction of the need for extracorporeal membrane oxygenation (P> .05). Both intraoperator and interoperator reproducibility were good for the standardized lung-to-head ratio (intraclass correlation coefficient, 0.98 [95% confidence interval, 0.97-0.99]; bias, 0.02 [limits of agreement, -0.11 to +0.15], respectively).

Conclusions: Standardization of lung-to-head ratio measurements improves prediction of neonatal outcomes. Further studies are needed to confirm these results and to assess the utility of standardization of other prognostic parameters.

Keywords: congenital diaphragmatic hernia; fetal lung; lung-to-head ratio; obstetric ultrasound; pulmonary hypoplasia; standardization.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anatomic Landmarks / diagnostic imaging
  • Female
  • Head / diagnostic imaging*
  • Head / embryology
  • Hernias, Diaphragmatic, Congenital / diagnostic imaging*
  • Hernias, Diaphragmatic, Congenital / therapy
  • Humans
  • Image Interpretation, Computer-Assisted / standards
  • Infant, Newborn
  • Lung / diagnostic imaging*
  • Lung / embryology
  • Male
  • Outcome Assessment, Health Care / standards*
  • Practice Guidelines as Topic*
  • Pregnancy
  • Pregnancy Outcome
  • Prognosis
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Texas
  • Treatment Outcome
  • Ultrasonography, Prenatal / standards*