Diagnostic accuracy of transthoracic ultrasound for detection of pneumothorax, hemothorax, and lung contusion in trauma patients: comparison with chest radiography.

BACKGROUND: Thoracic trauma is a major cause of morbidity and mortality in trauma patients. Rapid detection of pneumothorax, hemothorax, and lung contusion is critical for timely management. This study aimed to evaluate the diagnostic accuracy of transthoracic ultrasound compared with chest radiography in thoracic trauma patients using chest computed tomography (CT) as the reference standard. METHODS: This prospective diagnostic accuracy study was conducted in the Emergency Department of Menoufia University Hospital between July 2023 and December 2024. Adult trauma patients with suspected thoracic injury were consecutively enrolled. All patients underwent transthoracic ultrasound, chest radiography, and chest CT. Diagnostic performance of ultrasound and chest radiography for detecting pneumothorax, hemothorax, and lung contusion was assessed using CT as the reference standard. Sensitivity, specificity, predictive values, accuracy, and Cohen's kappa agreement were calculated. RESULTS: A total of 76 trauma patients were included in the final analysis (mean age 42.5 ± 12.7 years; 77.6% male), with blunt trauma accounting for 78.9% of injuries. CT identified pneumothorax in 45 patients (59.2%), hemothorax in 53 (69.7%), and lung contusion in 57 (75.0%). Transthoracic ultrasound detected pneumothorax in 41 patients (53.9%), hemothorax in 51 (67.1%), and lung contusion in 49 (64.5%), whereas chest radiography detected these injuries in 31 (40.8%), 33 (43.4%), and 14 patients (18.4%), respectively. Ultrasound demonstrated higher diagnostic performance than chest radiography across all injury types. For pneumothorax detection, ultrasound showed 91% sensitivity and 95% diagnostic accuracy compared with 69% sensitivity and 82% accuracy for chest radiography. For hemothorax detection, ultrasound achieved 96% sensitivity and 97% accuracy versus 62% sensitivity and 74% accuracy for chest radiography. For lung contusion detection, ultrasound demonstrated 86% sensitivity and 89% accuracy, whereas chest radiography showed only 25% sensitivity and 43% accuracy. Agreement with CT was strong for ultrasound (κ = 0.75-0.94) but lower for chest radiography (κ = 0.14-0.64). CONCLUSION: Transthoracic ultrasound demonstrated high diagnostic performance and good agreement with chest CT for detecting traumatic thoracic injuries and outperformed chest radiography in this study. However, given the single-center design and relatively limited sample size, larger multicenter studies are warranted to validate these findings.