Approximately 7.3% of all live births in Egypt are premature; meaning they are born before 37 weeks of gestation1. One of the most significant complications of prematurity is respiratory distress syndrome (RDS), which is the most common cause of respiratory distress in premature infants, correlating with structural and functional lung immaturity, and this is the most common cause of neonatal mortality4. A number of biochemical tests have been developed to predict the risk of RDS. These tests, such as lecithin/sphingomyelin (L/S) ratio, require amniocentesis5. Non-invasive methods using ultrasound to assess foetal lung maturity (FLM) have long been proposed, such as measurement of lung volume, gestational age, epiphysis centres, placental grading, and estimated foetal weight, but none have been successful6–9. This prompted us to try to investigate other non-invasive sonographic techniques to evaluate lung maturity; namely, quantitative ultrasound texture analysis and pulmonary artery Doppler.

Quantus FLM foetal lung maturity test.

Our observational prospective cohort study included pregnant women between 28 and 40 weeks of gestation. The diagnostic accuracy of MPA Doppler measurements (pulsatility index [PI]), resistance index [RI] and acceleration time/ejection time [AT/ET]) for diagnosis of neonatal RDS was tested by comparing the Doppler findings with the clinical outcome.

Our study included 40 patients who delivered at Minia University Maternity and Children’s Hospital in Minia, Egypt, in the period from May to December 2018.

Of the 40 eligible foetuses, nine (22%) developed neonatal RDS. There was a significant correlation between the AT/ET and the development of RDS as the AT/ET was significantly lower in the RDS positive group (mean 0.27) in comparison to the RDS negative group (mean 0.34) (P 0.001), while both PI and RI showed no statistically significant difference between the two groups. A cut-off value of 0.3 for AT/ET predicted the development of RDS (sensitivity: 77.78%, specificity: 83.87%).

Spike and dome pattern of pulmonary artery Doppler ultrasound.

In conclusion, one can say that both Quantus FLM (a non-invasive foetal lung maturity test) and foetal pulmonary artery AT/ET are comparable in predicting foetal lung maturity.

Dr. Nasr Mohamed M. Osman, MD is Associate Professor of Radiology at El Minia University in Minia, Egypt.

References
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6 Osada H, Iitsuka Y, Masuda K, Sakamoto R, Kaku K, Seki K, Sekiya S. Application of lung volume measurement by three-dimensional ultrasonography for clinical assessment of fetal lung development. J Ultrasound Med 2002 Aug;21(8):841–847
7 Deter RL, Hadlock FP, Carollo BR. Ultrasonically determined menstrual age as an indicator of fetal lung maturity. J Clin Ultrasound 1982 April;10(4):153–157
8 Harman CR, Manning FA, Stearns E, Morrison I: The correlation of ultrasonic placental grading and fetal pulmonary maturation in five hundred sixty-three pregnancies. Am J Obstet Gynecol 1982 Aug 15; 143(8):941–943
9 Tabsh KM. Correlation of ultrasonic epiphyseal centers and the lecithin: sphingomyelin ratio. Obst Gynecol 1984 Jul;64(1):92–96

Research Presentation Session
RPS 1005a Radiomics and texture analysis

Quantitative ultrasound texture analysis of the foetal lung versus foetal pulmonary artery Doppler as a non-invasive predictor of neonatal respiratory distress syndrome (RDS)
N. Osman; Minia/EG

Read the full abstract in the ECR 2020 Book of Abstracts
Osman N. (2020) Quantitative ultrasound texture analysis of the foetal lung versus foetal pulmonary artery Doppler as a non-invasive predictor of neonatal respiratory distress syndrome (RDS). Abstract RPS 1005a-3 in: ECR 2020 Book of Abstracts. Insights Imaging 11, 34 (2020). DOI 10.1186/s13244-020-00851-0