A patient after diagnostic videothoracoscopy, after having had a right lung biopsy, followed by the development of a post-operative pneumothorax with chest drainage and the development of subcutaneous emphysema.

The pleural line is not visible. The parietal emphysema causes comet tail artefacts that do not fan out from the pleural line, but randomly from the structures of the chest wall, where there is air causing these artefacts. The artefacts are named W-lines. If emphysema is large and increased pressure of the probe on the chest wall does not help (this will displace the air to the surrounding area), it is impossible to undertake a further examination.