Lung Ultrasound

Last Updated on August 19, 2026

Preparation

• Patient’s position: supine
• Preset: lung
• Probe: curvilinear B and M mode
• Probe position: anterior chest wall mid clavicular line, sagittal plane; R1 / L1

Signs

⚽️ A-lines
– Repetitive horizontal artifacts that recur at recur at regular intervals that are equal to distance between probe-skin interface and pleural-subpleural air interface
– Not representing any pathology

⚽️ B-lines
– (Typically 3 or more) Discrete laser-like vertical hyperechoeic reverberation artifacts that arise from pleural line, extending to the bottom of the screen without fading, and move synchronously with lung sliding if lung sliding is present
– Videos: Video 1

⚽️ Lung point
– Alternating presence and absence of lung sliding during respiration

⚽️ Lung sliding (B-mode) // Sea-shore appearance (M-mode)
– Lung sliding: Shimmering effect on the pleural produced when parietal pleura (outer layer) slides over visceral pleura (inner layer) during respiration
– Normal = present of lung sliding
– Causes of absent lung sliding : pneumothorax, pleurodesis, endobronchial intubation

⚽️ ‘Stratosphere’ sign // ‘Barcode’ sign (M-mode)
– ‘Sandy’ pattern below pleural is lost, replaced by straight horizontal lines

⚽️ Z-lines
– Discrete laser-like vertical hyperechoeic reverberation artifacts that arise from pleural line, fading away before reaching bottom of the screen
– Not representing any pathology but should not be mistaken as B-lines

Further Reading

1. Lung quadrants in lung ultrasound (R1 – R6; L1 – L6)
2. FB Amalina Nudin

Related Posts

1. FAST scan
2. Pneumothorax