Turning the tide (and the probe)-sonographic liver measurement in the right lateral anterior axillary line is a reliable alternative to the standard frontal approach in term and preterm infants.

Purpose: In term and preterm infants, liver size is important for assessing growth and detecting conditions such as hepatomegaly, infections, or cardiac failure. The German Society for Ultrasound in Medicine (DEGUM) recommends measuring craniocaudal liver length in two frontal planes: the midsternal line (MSL) and the right anterior axillary line (AAL). This study evaluated whether liver length measurements in the right AAL from a lateral view yield results comparable to the standard frontal view, as the lateral approach may be technically more accessible and less stressful for neonates.

Material and methods: In this prospective single-center study conducted in a level III neonatal intensive care unit, 62 term and preterm infants underwent 107 liver measurements between July and December 2024. Each measurement was performed in both the frontal and the alternative lateral AAL plane. Statistical analysis included Wilcoxon matched-pairs signed rank test, Pearson Correlation Coefficient, and Bland-Altman analysis.

Results: The median liver length was 4.7 cm in both methods (interquartile range 1.5 cm frontal, 1.4 cm lateral). The correlation between approaches was excellent (r = 0.9971), and Bland-Altman analysis showed a median difference of 0 cm, with 99.1% of measurements within the limits of agreement (- 0.3 cm to 0.2 cm).

Conclusion: Sonographic liver measurement in the lateral AAL yields results equivalent to the standard frontal method and may offer a practical alternative when standard access is limited. Supporting minimal handling of newborns, the approach is particularly relevant in neonatal intensive care and provides a methodological basis for further evaluation of the lateral view.