Absence of lung sliding due to pneumothorax

Lung sliding is the respirophasic shimmering to and fro movement of the visceral and parietal pleural surface. The presence of lung sliding indicates that the lung is fully inflated at the site of probe placement on the chest wall, so there is no pneumothorax at that examination site. The absence of lung sliding indicates the possibility of pneumothorax, as there are other causes for its absence. A lines are present and derive from a normally aerated lung (panel A) or from the presence of air within the pneumothorax space (panel B).