Heterogeneity Index in Neonatologist-performed Lung Ultrasound in Neonates Receiving Respiratory Support - a Pilot Study

Lung ultrasound is gaining importance in intensive care medicine, particularly in neonatology, as a rapidly available, and radiation-free alternative to X-ray imaging. Neonatologist-performed lung ultrasound (NPLUS) enables reliable diagnosis of various respiratory conditions in both preterm and term neonates. It relies on interpreting ultrasound artifacts, pleural line analysis, and detecting consolidations or effusions, thus significantly improving differential diagnosis of neonatal respiratory symptoms. Semi-quantitative lung ultrasound scoring systems have been developed to assess pulmonary aeration patterns and guide clinical decisions-e.g., detecting surfactant deficiency in preterm infants or identifying 'wet lung' in term neonates. However, subtle sonographic changes related to respiratory symptoms may not be adequately captured on the current 0-3 scale and are subject to interobserver variability. In obstetrics, a heterogeneity index has been introduced to quantitatively assess fetal lung texture with high diagnostic accuracy for postnatal respiratory outcomes. This study aims to introduce a quantitative ultrasound method into clinical routine to improve diagnostic precision in NPLUS. To our knowledge, this approach has not yet been applied in this context. In this pilot study, 20 preterm (28+0 to 36+6 weeks) and 20 term (≥37+0 weeks) neonates receiving non-invasive or invasive respiratory support in the NICU will undergo NPLUS at two time points. From the raw ultrasound data, a mean pixel value will be calculated to derive the heterogeneity index, which will then be compared to the traditional lung ultrasound score to assess its clinical relevance.