Figure 2

Ultrasound detection of pneumothorax. Symbols: Wide arrow, pleural line; thin arrow, lung point; X, rib shadow. A) The pleural line between two ribs is identified close to the sternum. B) The probe is rotated to align in the intercostal space and then gradually moved towards the lateral-posterior area of the chest, always following the pleural line. The aim is to detect “to and fro” horizontal movement at the pleural line, which is called lung sliding, excluding air between the pleural layers (visible only on video clips). Even with a pneumothorax present, the lung is still in contact with the interior chest wall. This contact point is called the “lung point” and moves in and out of the ultrasound screen alongside the pleural line, synchronous with respiration (visible only on video clips). The lung point is 100% pathognomonic for pneumothorax. C) In time-motion mode, the lung point appears as two distinct sonographic patterns; one pattern is suggestive of normal lung sliding (seashore pattern) and is interposed by horizontal lines (stratosphere pattern) that are seen when intrapleural air is present.