Accuracy of lung ultrasonography versus plain chest X-ray in diagnosis of pneumonia

Background Ultrasound interrogation of the thorax for detection of pneumonia has been explored most in critical care and emergency department settings. However, recently, the application has spread to general practice and even prehospital settings. This work aimed to evaluate the role of chest ultrasound as a diagnostic tool for pneumonia in adults compared to chest x-ray. Methods This prospective observational cross-sectional study was carried out on 30 adult patients admitted to the General Chest Departments of Desouk and Damanhour Hospitals with a preliminary diagnosis of community-acquired pneumonia. The studied patient were divided into two groups: Group I: 21 patients (70%) with final diagnosis of pneumonia and group II: 9 patients (30%) with final diagnosis other than pneumonia. All patients underwent chest examination, vital signs, routine laboratory investigation including (white blood cell count and ESR) and lung ultrasound. Results Considering discharge diagnosis as the reference standard, ultrasound showed a sensitivity of 95.2% and a specificity of 88.9% with a PPV 95.2%, NPV 88.9% and accuracy of 90.3%. CXR fared much worse, with a sensitivity of 71.4 and a specificity of 66.7% with a PPV 83,3%, NPV 50.0% and accuracy of 70.0% and this is a statistically significant difference ( p < 0,001) between the two groups. Conclusions Bedside chest ultrasound was a reliable tool for diagnosing pneumonia in the hospital, probably being superior to CXR in this setting. It was likely that its wider use will allow a faster diagnosis of this disease, conducive to a more appropriate therapy.