Chest radiography is the primary imaging modality used for the assessment of neonatal respiratory distress syndrome (NRDS) in newborns. However, excessively exposing a growing neonate to harmful ionizing radiation may have long-term consequences. Some studies have shown that lung ultrasound (LUS) is helpful in the diagnosis of NRDS. A comprehensive search was carried out using PubMed, Embase, and the Cochrane Library to identify studies in which newborns with clinically suspected NRDS were assessed by LUS. Two investigators independently screened the literature and extracted the data. Any discrepancies were resolved via discussion with the senior author. Study quality was assessed by the Quality Assessment of Diagnostic Accuracy Studies 2 tool, and pooled sensitivity and specificity of various LUS findings for diagnosing NRDS were determined. Summary receiver operating characteristic curve was used to assess the overall performance of LUS. Ten studies with a total of 887 neonates were included in this meta-analysis. There was significant heterogeneity across the included studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for the diagnosis of NRDS using LUS were 0.92 (95% confidence interval [CI], 0.89-0.94), 0.95 (95% CI, 0.93-0.97), 20.23 (95% CI, 8.54-47.92), 0.07 (95% CI, 0.03-0.14), and 455.30 (95% CI, 153.01-1354.79), respectively. Furthermore, the summary receiver operating characteristic area under the curve was calculated to be 0.9888. The main LUS characteristics of NRDS include bilateral white lung, pleural line abnormalities, and lung consolidation. In summary, LUS is a highly valuable diagnostic technology that complements chest radiography in the diagnosis and follow-up monitoring of NRDS.

Aims: Foot and ankle injuries are a common presenting complaint in the emergency department. The diagnosis of foot and ankle fractures is conventionally accomplished through X-rays. Whether ultrasound (US) can be considered as a primary scanning modality is still a controversial issue; therefore, we did a meta-analysis to synthesize the diagnostic performance ofultrasound for foot and ankle fractures.Material and methods: A comprehensive search was carried out to identify studies in which patients with clinically suspected foot and ankle fractures were assessed by US. Two investigators independently screened the literature and extracted the data. Any discrepancies were resolved via discussion. Study quality was assessed by the Quality Assessment of Diagnostic Accuracy Studies 2 tool, and pooled sensitivity and specificity of various US findings were determined.Results: Ten studies with a total of 1065 patients were included. There was significant heterogeneity across the included studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for the diagnosis of foot and ankle fractures by US were 0.96 (95% confidence interval [CI], 0.90-0.99), 0.94 (95% CI, 0.88-0.97), 15.0 (95% CI, 7.9-28.6), 0.04 (95% CI, 0.02-0.11), and 367 (95% CI, 101-1338), respectively. Furthermore, the summary receiver operating characteristic area under the curve was calculated to be 0.99.Conclusions: Ultrasound has an excellent diagnostic performance for foot and ankle fractures and should be considered as a primary and radiation-free scanning modality in the diagnosis of foot and ankle fractures.