TOPLINE:

Computerised chest radiograph analysis revealed that the surfactant treatment led to better aeration in the right lung than in the left lung among infants born extremely preterm with respiratory distress syndrome (RDS). Basal regions showed improved aeration compared to apical regions regardless of surfactant treatment, suggesting anatomical influences on distribution patterns.

METHODOLOGY:

• Researchers conducted an observational study of 66 newborns with extremely low gestational age (22-27 weeks; 42% girls) at Uppsala University Children's Hospital, Sweden, between January 2021 and December 2022.
• The analysis included chest radiographs taken within 6 hours after surfactant administration in the surfactant-treated group (n = 52) and at matched timepoints before treatment in the pre-surfactant group (n = 8).
• Infants in the surfactant-treated group received a median of two doses of surfactant, whereas those in the pre-surfactant group received a single dose, both prophylactically immediately after birth.
• Digital images of the chest radiographs were obtained from the database (Telerad) and processed using ImageJ software in which 12 regions of interest were selected manually in the intercostal segments two to seven bilaterally.
• Outcomes included changes in the mean pixel intensity (MPI) that described the focal lung density and the focal heterogeneity in pixel intensity (FHPI) that estimated variation in the distribution of air in the regions of interest. Additionally, an independent visual grading of RDS was performed by two radiologists and compared with the computerised image analysis.

TAKEAWAY:

• The MPI was higher in the left lung than in the right lung for infants in the surfactant-treated group (P = .008) but not for those in the pre-surfactant group, indicating lower aeration in the left lung after surfactant administration.
• The MPI was significantly higher in apical than in basal regions bilaterally for infants in both the surfactant-treated group (right lung, P = .024; left lung, P = .015) and the pre-surfactant group (right lung, P = .047; left lung, P < .001), showing that this distribution was not influenced by the treatment.
• The FHPI was higher in the right than in the left seventh intercostal segment for infants in the surfactant-treated group (P = .006) and higher in the right seventh segment than in the matched one for those in the pre-surfactant group (P < .001).
• The grading by the radiologists was positively correlated with the computerised analysis of the MPI performed in ImageJ (P < .001).

IN PRACTICE:

"We hypothesize that surfactant probably reaches the right side more easily and the basal regions of the lung to a greater extent than the apical ones, leading to focal heterogeneous air distribution that might reflect a combination of both over-expanded and collapsed alveoli, observations that warrant continued future studies," the authors wrote.

SOURCE:

This study was led by Julia Fall, Department of Women's and Children's Health, Uppsala University Children's Hospital, Uppsala, Sweden. It was published online on October 14, 2025, in the European Journal of Pediatrics.

LIMITATIONS:

The initial selection of infants on the basis of surfactant treatment status and the timing of chest radiographs within 6 hours of administration might have introduced selection bias. The pre-surfactant group likely included infants with less severe initial RDS who did not meet the criteria for early surfactant replacement therapy. Additionally, the small sample size may have limited the ability to establish correlations between imaging findings and long-term outcomes.

DISCLOSURES:

This study was funded by Gillbergska Stiftelsen, Uppsala, Sweden. Open access funding was provided by Uppsala University. The authors declared having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.