Ultrasound vs. chest X-ray for dyspnea in the ER

Zanobetti et al prospectively evaluated 404 consecutive people presenting to one emergency room for dyspnea with point-of-care ultrasonography (all done by one MD) followed by chest radiograph. In the 118 instances when the tests provided discordant diagnoses, chest CT was obtained and was used as the gold standard. Concordance between US and CXR was high across all patients and diagnoses; US diagnoses were immediate, while CXR results took 1.5 hours. The authors suggest that US's speed could help relieve ER congestion, but acknowledge that real-world implementation with multiple MDs performing US would likely decrease its accuracy and replicability, at least at first. CHEST 2011;139:1140-1147.