Click on the button below to go to the main page:
Click on the button below to go to the previous page:
STANDARD VIEWS
Examine the anterolateral and posterior chest as described. We recommend imaging the anterolateral chest with the patient supine and the posterior chest with the patient sitting,
Aim to achieve the following standard views in each area:
Lichtenstein described the "bat sign" as the standard view when imaging the pleura (1). With the transducer oriented vertically on the chest, the marker oriented cranially: the image on the screen shows two ribs (bat wings) and pleura immediately deep to the ribs (bat body).
Aim to achieve this image each time. It will prevent errors such as assuming that subcutaneous air is pleura.
BAT SIGN (bat in orange): Ideal pleural image
Note: to achieve this image, decrease the depth so that the pleura is in the middle of the screen. Adjust the gain so that the pleura is white and the rib shadows are black.
If lung parenchymal pathology is seen, increase the depth to image this better.
BAT SIGN: two ribs (wings) and pleura (body)
At R4 and L4 begin with a depth of 15-20cm image the space above and below the diaphragm. You will visualise the liver/spleen and diaphragm. Above this, the presence of normal lung will create pleura and A lines at the top of the screen and then anechoic dropout below this. This is due to the attenuating effect of air on US. If there is lung pathology, US will be able to penetrate deeper and you will see the vertebrae extending above the diaphragm (spine sign). You may need to angle down into the bed (posterior) to visualise the spine well.
To examine the pleura at L4/R4 always begin with a depth of 20cm, get your bearings and then decrease the depth to focus on the pleura. Too often, the sliding diaphragm is misdiagnosed as a lung point or the liver/ spleen is misdiagnosed as consolidation.
R4: top two images with a depth set at 16cm, the liver takes up the right side of the screen and the pleura is seen on the left top corner. The bottom two images show the same location with the depth decreased to specifically image the pleura.
SPINE SIGN: the vertebrae extend above the diaphragm
Click on the button below to go to the next page:
REFERENCES
1. Lichtenstein D. Lung ultrasound in the critically ill. Curr Opin Crit Care. 2014;20(3):315-322.