Page 47 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars
P. 47
ABCDE of prehospital ultrasonography 45
Figure 2.4 Pneumothorax + A-line
A-lines are reflections of the pleural line caused by gas below the parietal pleura. An A-line is indicated by the
arrows. The A is for “air” either within or outside of the lung.
In case of a pneumothorax, there are no B-lines (Figure 2.2) that may obscure the A-lines making them stand out more clearly.
Figure 2.5 Pneumothorax – M-mode ultrasound image
There is no visible movement neither above nor below the pleural line. Because all tissue and artefacts are station- ary, the M-mode image appears as horizontal straight lines throughout the image. This is called a barcode sign or stratosphere sign.
2
