Pleural Empyema

  • Etiology: infected fluid (pus) in pleural space
  • Imaging: nonspherical in shape, displaces lung, +/- loculated, split pleura sign (sign of fluid in pleural space), obtuse angles to chest wall, thickened pleura, enhancing rim sign (sign of pleural inflammation due to empyema)
  • US: shows loculations very well
  • DDX: lung abscess

Cases of Pleural Empyema

CXR and CT of pleural empyema
CXR PA and lateral shows complete opacification of the left hemithorax causing tracheal and mediastinal shift to the right, which is seen on the axial CT with contrast of the chest to be due to a large pleural fluid collection with an enhancing pleura causing near complete left lung atelectasis.
CXR and CT of subpulmonic pleural effusion and empyema
CXR AP (above) shows a right lower lobe infiltrate and elevation of the right hemidiaphragm and lateralization of its apex. Coronal 2D reconstruction from CT with contrast of the chest (below) shows a loculated fluid collection between the inferior border of the right lung and the right hemidiaphragm.