# Computer-assisted analysis of pleural and subpleural lung ultrasound correlates with oxygenation in preterm infants

## TL;DR

This study shows that quantitative lung ultrasound can predict oxygenation levels in preterm infants, with some measurements being consistent across different ultrasound machines.

## Contribution

The study introduces Q-LUScorrelation as a machine-independent measure of oxygenation in preterm infants.

## Key findings

- Mean-grey-value showed fair correlation with oxygenation metrics in preterm infants.
- Q-LUScorrelation was moderately correlated with oxygenation and consistent across ultrasound systems.
- Textural features outperformed MGV as a reliable oxygenation indicator.

## Abstract

Lung ultrasound (LUS) is increasingly used in neonatal intensive care, however visual scoring of LUS images remains subjective. Quantitative LUS (Q-LUS) is objective and whilst it detects small lung aeration changes in preterm animals, human data are limited. We hypothesised that Q-LUS would correlate strongly with oxygenation in very preterm infants born before 32 weeks’ gestation. We examined two quantitative image properties to assess whether Q-LUS correlates with oxygen status in very preterm infants: (1) mean-grey-value (MGV) and (2) second-order textural features (angular second moment, contrast, grey-level correlation (Q-LUScorrelation), inverse difference moment, entropy). 560 LUS images were acquired from 70 very preterm infants using Venue 50 and Venue Go systems and analysed in Fiji ImageJ. Oxygenation was assessed using oxygen saturation index (OSI) and peripheral oxygen saturation to fraction of inspired oxygen (S/F) ratio. Spearman’s rank correlation coefficient (ρ) was used to determine correlations between Q-LUS measurements and infant oxygenation. We found that MGV correlated fairly with OSI (ρ=-0.46, [-0.68,-0.23], p<0.01) and S/F ratio (ρ=0.38, [95% CI: 0.16,0.61]; p<0.01), though results varied by ultrasound system (Venue 50 (OSI: ρ=-0.43, [-0.69,-0.18], p<0.01; S/F ratio: ρ=0.34, [0.06,0.63], p=0.02) and Venue Go (OSI: ρ=0.12, [-0.61,0.83], p=0.71; S/F ratio: ρ=-0.24, [-0.85,0.37], p=0.36). Among textural features, Q-LUScorrelation was moderately correlated with OSI (ρ=0.48, [0.25,0.71], p <0.01) and S/F ratio (ρ=-0.54, [-0.74,-0.34], p <0.01), and was consistent across systems. Overall, Q-LUS showed fair-to-moderate correlation with oxygenation in very preterm infants. Q-LUScorrelation was the only textural feature unaffected by machine type, supporting its potential as a machine-independent, indirect measure of oxygenation.

The online version contains supplementary material available at 10.1038/s41598-026-39333-6.