FIGURE 3.

a) A simple pleural effusion. The fluid is homogeneous, hypoechoic and devoid of septation. To the right of the image, the diaphragm is seen; beneath it, the liver. b) A simple parapneumonic effusion. The pneumonic tissue is hypoechoic compared to adjacent structures and contains air bronchograms, small hyperechoic areas, representing air in the bronchi. c) A complicated parapneumonic effusion (Eff) with septation spanning from the diaphragm above the liver (Lvr) to the pneumonic lung (Pnm). d) Pleural effusion characterised by comprehensive fibrinous material, highly suggestive of empyema.