Emerging roles for transthoracic ultrasonography in pleuropulmonary pathology

Table 1 Main findings in TUS study of lung and pleura

TUS finding	Definition
Gliding sign or lung sliding	Respiration-dependent movement of the visceral pleura and lung surface with respect to the parietal pleura and chest wall. Normal finding
Reverberation artefacts	Multiple parallel transversal echoes departing from and reproducing the pleural line. Normal finding
Comet-tail artefacts	Discrete thickening comet-tail like echoes originating from the pleura. Normal finding1
Ring-down artefacts	Vertical spreading in the depth echoes. Edema; interstitial diseases
Lung point	Boundary between pneumothorax and aerated lung
Lung pulse	Slow sliding depending on heart beats. It excludes PNX; can suggest atelectasis
Bronchogram	Air inside the bronchi2

¹Generally sporadic, becoming more numerous in diffuse parenchymal diseases;

²If air moves inside the bronchi (dynamic bronchogram), atelectasis is excluded. If air does not move and appears as multiple parallel and fixed echogenic strains, it suggests atelectasis. TUS: Transthoracic ultrasonography.