Right middle lobe collapse following right upper lobectomy.

Radiographic and computed tomographic (CT) examinations of the chest in four patients with collapse of the right middle lobe of the lung after lobectomy of the right upper lobe were reviewed. The diagnosis of collapse was made on the basis of findings of increased density in the right middle lobe and volume loss evidenced by displacement of the neofissure seen at CT. Plain radiographic findings included opacity in the right hilar and paramediastinal areas in all four patients, with smooth margination simulating mediastinal widening in three.