Lung Ultrasonography: A Viable Alternative to Chest Radiography in Children with Suspected Pneumonia?

OBJECTIVE: To determine the interrater reliability (IRR) of lung ultrasonography (LUS) and chest radiography (CXR) and evaluate the accuracy of LUS compared with CXR for detecting pediatric pneumonia compared with chest computed tomography (CT) scan.

STUDY DESIGN: This was a prospective cohort study of children aged 3 months to 18 years with a CXR and LUS performed between May 1, 2012, and January 31, 2014 with or without a clinical diagnosis of pneumonia. Four pediatric radiologists blinded to clinical information reported findings for the CXR and LUS images. IRR was estimated for 50 LUS and CXR images. The main outcome was the finding from CT ordered clinically or the probability of the CT finding for patients clinically requiring CT. Two radiologists reviewed CT scans to determine an overall finding. Latent class analysis was used to evaluate the sensitivity and specificity for findings (eg, consolidation) for LUS and CXR compared with CT.

RESULTS: Of the 132 patients in the cohort, 36 (27%) had CT performed for a clinical reason. Pneumonia was clinically documented in 47 patients (36%). The IRR for lung consolidation was 0.55 (95% CI, 0.40-0.70) for LUS and 0.36 (95% CI, 0.21-0.51) for CXR. The sensitivity for detecting consolidation, interstitial disease, and pleural effusion was statistically similar for LUS and CXR compared with CT; however, specificity was higher for CXR. The negative predictive value was similar for CXR and LUS.

CONCLUSIONS: LUS has a sufficiently high IRR for detection of consolidation. Compared with CT, LUS and CXR have similar sensitivity, but CXR is more specific for findings indicating pneumonia.