Among the 85 pediatric patients enrolled, 74 (87.1%) were diagnosed with viral infections, while 11 (12.9%) had bacterial pneumonia. LUS findings demonstrated a clear distinction between bacterial and viral pneumonia cases.

Patients with bacterial pneumonia exhibited significantly higher LUSS (median = 10, range 8–13.5) compared to those with viral infections (median = 3, range 1–6) (p < 0.0001).

Fig 2: LUSS Comparison: A box plot comparing the Lung Ultrasound Score (LUSS) between bacterial and viral pneumonia.

Specific LUS abnormalities, including confluent B-lines, pleural irregularities, and subpleural consolidations, were observed more frequently in bacterial pneumonia cases. Notably, large consolidations (> 1 cm) were detected exclusively in bacterial pneumonia cases. Conversely, viral pneumonia was characterized by more diffuse B-lines, indicative of interstitial involvement, and the absence of large consolidations.

Fig 3: Ultrasound Findings Prevalence: A bar chart showing the frequency of ultrasound findings in bacterial vs. viral pneumonia.

ROC curve analysis revealed that the presence of large consolidations had a sensitivity and specificity of 100% for bacterial pneumonia diagnosis.

Fig 4: ROC Curve Analysis: A ROC curve evaluating the performance of LUSS in distinguishing bacterial from viral pneumonia. ROC curve analysis revealed that the presence of large consolidations had a sensitivity and specificity of 100% for bacterial pneumonia diagnosis.

Additionally, a LUSS threshold of 9 or less was associated with 77.14% sensitivity and 80% specificity for viral pneumonia, further highlighting the diagnostic potential of LUS in differentiating between the two etiologies.

Fig 5: ROC Curve Analysis: The graph illustrates the sensitivity (77.14%) and specificity (80%) of a LUSS threshold of ≤9 for diagnosing viral pneumonia.

These findings suggest that LUS provides valuable diagnostic information that can aid clinicians in determining the etiology of pediatric pneumonia, potentially reducing reliance on ionizing imaging techniques and unnecessary antibiotic prescriptions.