The quantitative lung index (QLI): a gestational age–independent sonographic predictor of fetal lung growth

Quantitative Lung Index, Contralateral Lung Area, or Lung-to-Head Ratio to Predict the Neonatal Outcome in Isolated Congenital Diaphragmatic Hernia?

“…In this study, our aim was to estimate and compare the accuracies of the various available predictive models for neonatal morbidity and mortality in cases of isolated congenital diaphragmatic hernia. More specifically, we sought to estimate the accuracy of the quantitative lung index as proposed by Quintero et al 13 compared to the observed‐to‐expected contralateral lung area, lung‐to‐head ratio, observed‐to‐expected lung‐to‐head ratio, and observed‐to‐expected total lung volume. Although, as suggested by Quintero et al, 13 there is a theoretical mathematical discussion to correct the ratio between the contralateral lung area and fetal head circumference for prediction of the neonatal outcome in isolated congenital diaphragmatic hernia, our results continue to support the concept that measuring the contralateral lung sizes is less effective than measuring the total lung volume 12 …”

“…Fetal biometric and lung measurements were performed with a Voluson 730 ultrasound machine (GE Healthcare, Zipf, Austria) between 26 and 30 weeks' gestation. The observed‐to‐expected contralateral lung area was obtained by measuring the contralateral lung area at 26 to 30 weeks' gestation and using the nomogram reported by Peralta et al 11 The quantitative lung index was calculated according to the formula of Quintero et al 13 The lung‐to‐head ratio and observed‐to‐expected total lung volume were calculated using the formulas of Metkus et al 8 and Ruano et al 14 , 15 …”

“…However, the discussion on the best prenatal sonographic predictors of the neonatal outcome in isolated congenital diaphragmatic hernia continues. In fact, citing the impact of gestational age, Quintero et al 13 recently suggested the use of the quantitative lung index, which is calculated as quantitative lung index = contralateral lung area/(head circumference/10) 2 .…”

Pulmonary hypoplasia in fetuses with congenital conotruncal defects

“…[7][8][9] In this study, we use the lung areas and Z-scores as the major PH measurements and take the other PH variables into account as well. [7][8][9] In this study, we use the lung areas and Z-scores as the major PH measurements and take the other PH variables into account as well.…”

Reference Ranges for 2‐Dimensional Sonographic Lung Measurements in Healthy Fetuses

“…To avoid the influence of menstrual age, some authors suggested using the observed‐to‐expected lung‐to‐head ratio, and others advocated changing the mathematical equation to the quantitative lung index 14 , 23 . Theoretically, the quantitative lung index would not vary with respect to menstrual age, based on the mathematical theory.…”