Lung: Pleural Effusion

1. 1

   Position patient sitting upright or in lateral decubitus. Select curvilinear probe.

2. 2

   Place probe in the posterior-lateral chest, above the diaphragm, marker toward the head.

3. 3

   Identify the diaphragm as the bright curved structure. Effusion appears as anechoic space above it.

4. 4

   Use the spine sign on the left: if vertebral bodies are visible below the diaphragm, effusion is present.

5. 5

   Characterize the effusion: simple (anechoic) vs. complex (echogenic debris, septations).

6. 6

   Measure the maximal depth of the effusion. Estimate volume: depth (cm) × 90 ≈ volume (mL).

7. 7

   Assess for lung compressive atelectasis (echogenic consolidated lung floating in fluid).

• Posterior-lateral chest (sitting or lateral decubitus)
• Diaphragm visualization

• Anechoic vs. complex effusion
• Diaphragm descent
• Compressive atelectasis
• Fibrinous septations

• Confusing ascites with pleural effusion — find diaphragm landmark

Spine sign: if vertebrae visible below diaphragm on left side, effusion present.