Chest ultrasound in neonates: What neonatologists should know

Table 1 Lung ultrasound appearance in different neonatal lung diseases compared to chest X-ray

Disease	Chest X-ray	Lung ultrasound
Pleural effusion	Homogenous opacity obliterating costophrenic and cardiophrenic angles	B-mode: Fluid is anechoic, sometimes ± hepatization of the lung parenchyma. M-mode: The sinusoid sign with the visceral line moving towards the pleural line during respiration
Pneumonia	Homogeneous opacities that can be patchy or lobar in distribution	Consolidation areas with irregular margins surrounding multiple B-lines. Invisible pleural line on the affected area. Sometimes: Dynamic air bronchogram
RDS	Alveolar shadowing (ground glass) with air bronchogram	Compact coalescent B-lines (white lung). Thickened, irregular pleural line. Multiple areas of sub-pleural consolidation
Atelectasis	Area of opacity in the lung with features of volume loss as shifting of mediastinum to the same side, pulled fissure, etc.	Area of consolidation with anechoic clear border and disrupted A-lines. Static air bronchogram. Complete collapse leads to the absence of lung sliding, lung hepatization, and lung pulse signs
Pneumothorax	Jet black translucency with collapsed lung and sometimes mediastinal shift to the other side	Absent lung sliding, absent B-lines, and the presence of lung point
TTN	Interstitial oedema predominantly in the peri-hilar region (wet silhouette)	Double lung point sign. B-lines. In severe cases: (white lung)
BPD	Ill-defined diffuse reticular markings with circular lucent areas in between and hyperinflated lung	Thickened coarse pleural linesSubpleural areas of consolidation. B-lines
MAS	Patchy consolidation	Same as pneumonia

BPD: Bronchopulmonary dysplasia; MAS: Meconium aspiration syndrome; RDS: respiratory distress syndrome; TTN: Transient tachypnoea of the newborn.