Chest sonography. Differentiation of pulmonary consolidation from pleural disease.

Ultrasonography was used to evaluate 53 patients with equivocal juxta-diaphragmatic and/or lateral densities in chest radiographs. An air bronchogram, fluid bronchogram, and scattered echogenic foci due to residual air in the consolidated lung parenchyma were used as US criteria of pulmonary parenchymal consolidation. One or more of these signs were observed in 39 patients with a clinical or bacteriologic diagnosis of pneumonia. The US air bronchogram was seen in 32 of the 39 patients (82%), the fluid bronchogram in 37 patients (94%) and the scattered echogenic foci in 30 (77%). In 14 patients, pleural effusion was diagnosed sonographically and verified by aspiration of fluid. The final diagnoses in these cases were pulmonary tuberculosis in 11 patients, staphylococcal empyema in 2, and tuberculous empyema in one patient. It is concluded that US criteria provide a useful differentiation of pulmonary parenchymal consolidation from pleural effusion.