Symposium on Nonpulmonary Aspects in Chest Radiology. The pulmonary ligament

The pulmonary ligament forms an important attachment of the lower lobe to the mediastinum and therefore influences the ultimate configuration of pneumothorax, lower-lobe atelectasis, and mediastinal pleural effusions. Since the ligament consists of a double pleural sheath, under certain circumstances fluid, air, and so on can collect within it, producing a lesion of triangular configuration. The latter must be differentiated from an air cyst or atelectasis.