Medial pneumothorax refers to the abnormal collection of air on medial aspect of the pleural cavity. This occurs when the quantity of air is small.
Chest radiograph (supine)
Seen as a linear lucent area along the medial aspect of lung at the interface of the pleural surface and the mediastinum. This is known as medial stripe sign. Findings are more pronounced on an expiratory film.
On a supine radiograph consider