CXR AP (above) shows subtle increased lucency of the right middle lobe. AP and oblique images from a vintage bronchogram 3 years later performed by injecting contrast in the right mainstem bronchus (below) shows a hyperlucent and hyperexpanded right middle lobe and contrast filling the airways of the collapsed right upper lobe and the right lower lobe but no contrast filling the airways of the hyperexpanded right middle lobe.
Pediatric Imaging 