Lung ultrasound and community-acquired pneumonia: from complementary tool to clinical game-changer

Community-acquired pneumonia (CAP) remains a major global health concern, traditionally diagnosed through chest X-ray (CXR). However, lung ultrasound (LUS) is increasingly emerging as a transformative tool in both diagnosis and management. Evidence from recent meta-analyses reveals that LUS outperforms CXR in sensitivity and rivals it in specificity, with pooled diagnostic accuracies exceeding 90 %. Unlike CXR, LUS is radiation-free, cost-effective, and ideal for bedside use, making it particularly valuable in emergency departments, intensive care units, pediatric and geriatric populations, and resource-limited settings. In children, LUS spares radiation exposure, while in elderly patients, contrast-enhanced ultrasound improves diagnostic specificity. Beyond diagnosis, LUS enables dynamic monitoring, prognostic scoring (e.g., LUS score, CPIS-PLUS), and supports treatment decisions such as ventilator weaning and antibiotic stewardship. Recent applications during the COVID-19 pandemic have demonstrated its effectiveness in triage and outcome prediction. Despite challenges such as operator dependency and reduced penetration for deep lesions, technological advances-particularly artificial intelligence and handheld devices-are mitigating these limitations. Deep learning models now interpret LUS images with high accuracy, enhancing reproducibility and accessibility for general practitioners. In low- and middle-income countries, LUS serves as a crucial diagnostic bridge, improving access and reducing reliance on costly imaging modalities. As training programs and standardized scoring systems evolve, LUS is becoming a frontline tool rather than a supplementary option. Its integration into clinical practice promises to reshape pneumonia care through rapid, accurate, and scalable diagnostics. In light of these advancements, LUS is not just complementary to radiography-it is redefining the diagnostic landscape of pneumonia.