Figure 12.

The right upper lobe collapses into a triangular opacity with the lesser fissure migrating toward the anterior, superior and medial portions of the chest, closing like a Chinese fan. On an AP chest radiograph, the most striking feature is a superior and medial displacement of the minor fissure. Note also the raised right hemidiaphragm. On the lateral radiograph (not shown), the major fissure moves anteriorly, while the superior movement of the minor fissure is also seen. This atelectasis was secondary to a mucusplug