Comparison of ultrasound and CT in the evaluation of pneumonia complicated by parapneumonic effusion in children

OBJECTIVE. The purpose of our study was to compare chest ultrasound and chest CT in children with complicated pneumonia and parapneumonic effusion. MATERIALS AND METHODS. We retrospectively compared chest ultrasound and chest CT in 19 children (nine girls and 10 boys; age range, 8 months-17 years) admitted with complicated pneumonia and parapneumonic effusion between December 2006 and January 2009. Images were evaluated for effusion, loculation, fibrin strands, parenchymal consolidation, necrosis, and abscess. In the subset of patients who underwent surgical management, imaging findings were correlated with operative findings. RESULTS. Eighteen of 19 patients had an effusion on both chest ultrasound and chest CT. The findings of effusion loculation as well as parenchymal consolidation and necrosis or abscess were similar between the two techniques. Chest ultrasound was better able to visualize fibrin strands within the effusions. Of the 14 patients who underwent video-assisted thoracoscopy, five had surgically proven parenchymal abscess or necrosis. Preoperatively, chest ultrasound was able to show parenchymal abscess or necrosis in four patients, whereas chest CT was able to show parenchymal abscess or necrosis in three. CONCLUSION. In our series, chest ultrasound and chest CT were similar in their ability to detect loculated effusion and lung necrosis or abscess resulting from complicated pneumonia. Chest CT did not provide any additional clinically useful information that was not also seen on chest ultrasound. We suggest that the imaging workup of complicated pediatric pneumonia include chest radiography and chest ultrasound, reserving chest CT for cases in which the chest ultrasound is technically limited or discrepant with the clinical findings.