Lung ultrasound for pneumonia diagnosis: A systematic review and meta-analysis of diagnostic performance.

BACKGROUND

Pneumonia is one of the primary causes of morbidity and mortality in the world, especially in children, the older population, and patients with critical conditions. The traditional imaging methods, including chest X-ray (CXR) and computed tomography (CT), are associated with diagnostic drawbacks in sensitivity, radiation exposure, cost, and availability. Lung ultrasound (LUS) has emerged as a promising bedside imaging modality for identifying pneumonia because it is portable, safe, and can be used for real-time diagnosis. The aim of this systematic review and meta-analysis was to assess the diagnostic validity of LUS for pneumonia across heterogeneous patient groups and conditions.

METHODS

Studies published within the period of January 2015 to December 2025 were searched using a systematic literature search in PubMed/MEDLINE, Embase, Scopus, Web of Science, and Cochrane Library. The progress of removing LUS from pneumonia diagnosis using a reference standard was incorporated in studies. Information on true positives, false positives, true negatives, and false negatives was obtained. The quality of the study was determined using the QUADAS-2 tool. The pooled sensitivity, specificity, likelihood ratios and diagnostic odds ratios (DOR) were estimated using a bivariate random-effects meta-analysis model.

RESULTS

The systematic review included 53 studies and 13,847 patients; 44 of these (7969 patients) were included in the quantitative meta-analysis. The pooled sensitivity of LUS in the diagnosis of pneumonia was 93.9 (95% CI: 90.9-96.0), and the pooled specificity was 84.9 (77.8-90.0). The pooled likelihood ratio was positive (6.23), and the negative likelihood ratio was 0.07 (95% CI: 0.047-0.108). The total diagnostic odds ratio was 87.43 (95% CI: 45.90166.54), which represents excellent diagnostic performance.

CONCLUSION

Lung ultrasound has high diagnostic accuracy for pneumonia in a wide range of patient populations and clinical conditions. LUS is a useful diagnostic tool that can be used as an adjunct to, or even as an alternative to, traditional imaging in selected clinical settings, as it is portable, does not involve radiation, and has strong rule-out capability.

PLAIN LANGUAGE SUMMARY: Pneumonia is a serious lung infection, and accurate diagnosis is important for safe and timely treatment. This study reviewed many research papers to evaluate how well lung ultrasound, a safe scan that uses sound waves, can detect pneumonia across different groups of people. This study found that lung ultrasound has high accuracy for diagnosing pneumonia and performs well in identifying and ruling out the condition. This matters because it can provide a safe, low-cost way to help diagnose patients, especially where other scans are harder to access.