This study was conducted at the ‘Dr. Victor Babes’ Clinical Hospital of Infectious Diseases and Pneumophthisiology Timisoara between February 2022 and October 2023.

A total of 85 children, aged 1 month to 14 years, were prospectively recruited following a clinical diagnosis of LRTIs. All patients underwent comprehensive clinical evaluation, including history-taking, physical examination, and laboratory testing.

Fig 1: Flow diagram of the progress through the stages (enrollment, allocation, and analysis of the patients).

LUS was performed using a 12-zone scoring system to quantify lung involvement, with scores assigned based on the presence and severity of specific ultrasound features, including B-lines, pleural abnormalities, subpleural consolidations, and large consolidations (> 1 cm).

A multiplex PCR test was utilized to confirm the viral or bacterial etiology of pneumonia.

Statistical analysis was conducted using the Mann-Whitney U test to compare LUSS between groups, with Bonferroni correction applied to account for multiple comparisons. Receiver operating characteristic (ROC) curve analysis was used to determine the sensitivity and specificity of LUS findings in differentiating bacterial from viral pneumonia.