This infographic explores artifacts in point-of-care ultrasound (POCUS) to aid diagnosis when performing a ultrasound on the lungs. Note the differences between the A-lines and B-lines scans.
Multiple repeating horizontal lines that are parallel and equidistant from the pleura.
This can be a normal finding in the healthy patient (dry lung) but, A lines may also be prominent in patients with atelectasis, asthma, COPD (positive lung sliding at pleural line), and pneumothorax (negative lung sliding at pleural line).
Transient, hyperechoic vertical lines that extend from the pleura to the bottom of the screen at a depth of 16cm.
Less than 2 B lines in any given region can be a normal finding; 3 or more B lines in any given region is pathologic (Wet Lung).
Focal B lines may suggest pneumonia, whereas diffuse B lines in 3 or more zones on both sides of the chest suggests a diffuse alveolar interstitial syndrome such as pulmonary edema or ARDS. With focal or diffuse B lines with spared regions of the pleura that lack B lines, a focal or bilateral pneumonia may be present or there could be signs of pulmonary embolism (focal, hypoechoic subpleural region) or cancer (focal or diffuse; hyperechoic)