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