How to differentiate pleural effusion and pulmonary edema in an x-ray?

Different: Pleural effusion is fluid around the lung. Pulmonary edema is fluid in the lung itself causing infiltrates and linear densities in the lung bases as the fluid distends the pulmonary lymphatics.

Mobiliy / location: Pleural effusion is fluid that accumulates in pleural lining around lungs and is usually mobile.Pulmonary edema is fluid that accumulates in interstitial or alveolar spaces of the lungs proper.Pleural fluid will change configuration or move in the pleural space from. by changing patient position. Edema in lung proper not very mobile.Pleural fluid is easily seen by ultrasound of chest as peripheral