B-line(s) is a lung artefact generated by an increased density of the underlying lung tissue. An example is when subpleural interlobular septae become edematous in cardiogenic pulmonary edema

A B-line is a hyperechoic (white), laser-like, vertical, reverberation artefact originating from the pleural line

B-lines are continuous from the pleural line to the bottom edge of the screen, do not fade in intensity

Understanding and performing basic lung ultrasound requires knowledge about:

– How to prepare the ultrasound system

– How the lung, pleura and chest wall structures appear on the ultrasound screen in 2D and M-mode mode

– The basic sonographic signs and artefacts used in lung ultrasound

– How to perform a basic lung examination using scanning zones

– How to identify or rule out pneumothorax, pleural effusion, and interstitial syndrome

– How to use lung ultrasound as an integrated part of goal directed patient assessment

Lung sliding is movement of the pleural line synchronous with the respiratory cycle

In addition, the pleural line may move in synchrony with the cardiac pulse

This movement, termed “lung pulse”, is caused by the force of the heart being transmitted to the lung and hence to the visceral pleura

Like lung sliding, lung pulse indicates that the visceral and parietal pleural surfaces are juxtaposed at the location of the probe

If there is pneumothorax, there will be no lung pulse

A means of assuring display of correct anatomy on the screen is by identifying the

The most important dynamic sign to be checked is

The lungs are protected and contained inside the chest cavity by the chest wall. The chest wall consists of ribs (syn: costae), and the soft tissues including muscles between the ribs in the intercostal space

The inside of the chest wall is covered by the parietal pleura, and the lung by the visceral pleura. The pleural space is delimited by the visceral and the parietal pleura

The visceral and parietal pleura normally lie close together with just a thin film of fluid in the pleural space

The visceral and parietal pleura slide against each other in synchrony with respiration

Costae are identified by the hyperechogenic (white) surface and the hypoechogenic (black) shadow below the costa

Pleura is seen as a hyperechogenic (white) structure between the costae

Things are not always as they seem

OBSERVE: Image structures below the pleura line do not represent lung tissue – the air in the lungs absorbs the ultrasound waves and returns no echoes. Structures seen in the image below the pleura line is not lung tissue but represent image artefacts from the echoes from the skin, muscle, costae and pleural line

In recent years, lung ultrasound has become popular as a clinical point-of-care tool in a variety of settings

The application of ultrasound for lung diagnostics has been considered impossible due to the air content of the normal aerated, as opposed to the sonographic examination of e.g. muscular and subcutaneous tissue not containing air

Deeply situated and aerated chest structures covered by bone can easily be examined with conventional ionising techniques like conventional X-ray and computed tomography (CT)

This accessibility of alternative techniques has been an obstacle to the development of lung ultrasound

You have now learned to apply the FAST examination in the process of learning focused ultrasound for optimisation in the trauma setting

You have learned:
– Where to place the transducer and how to orientate it in the 4 positions in the FAST protocol
– How to obtain the standard views in each position
– What to look for in the standard views
– How to evaluate whether free fluid is present

After completing this lesson you should understand how to:
– Perform a FAST examination
– Identify free fluid in anatomically specific locations

The target view is an image showing the target structures

The urinary bladder is displayed in the middle of the image

The right side of the patient’s bladder is seen on the left side of the ultrasound screen and left side of the bladder is seen on the right side of the ultrasound screen, when the OM is correctly pointing toward the right side of the patient in a transverse plane, and the OI is on the left side of the screen

The structures identified in the transverse P view:
– The urinary bladder
– Rectum behind the bladder

The best view of the bladder is seen when the bladder is full