The air bronchogram: sonographic demonstration.

A new sonographic pattern of pulmonary consolidation associated with air-filled bronchi in children is presented. The consolidated area of the lung is usually hypoechoic, poorly defined, and wedge-shaped. The air-filled bronchi produce linear, high-amplitude branching echoes that converge toward the lung root. Posterior acoustic shadowing and reverberation artifacts are seen accompanying the proximal large bronchi. A comparative study is presented in which 30 pediatric patients with clinical and radiographic evidence of pneumonia were sonographically evaluated. Twenty-eight patients were successfully examined with sonography. The cases were divided into three groups: (1) consolidated lung without pleural effusion (19 patients); (2) consolidated lung with small pleural effusion (five patients); and (3) consolidated lung with partial compression atelectasis due to large pleural effusion (four patients).