Table 2.

Differential diagnosis of lung diseases by ultrasound.

Ultrasonic features	Congenital tuberculosis	NRDS	BPD
Pleural line	Rough, irregular, hyperechoic, with segmental thinning or interruption	Blurry, absent, with visible “double lung point”	Early rough/blurry; late moth-eaten or cystic
B-lines	Fused or dense B-lines, unevenly distributed	Diffuse fused B-lines (pulmonary edema)	Early predominantly fused B-lines; late moth-eaten or cystic changes
Consolidation area	Multiple subpleural, extremely irregular in shape, with “shredded” edges; heterogeneous internal echoes, with more common hypoechoic areas	Homogeneous wedge-shaped consolidation with clear boundaries; obvious “snowflake” or “speckled” air bronchograms within	Early rare consolidation; late fibrosis with cord-like hyperechoic areas
Air bronchogram	Sparse or absent, with fragmented hyperechoic edges	Dense, uniform, punctate-linear air bronchograms	Absent (early) or cord-like (fibrotic phase)
Doppler flow signals	Abundant blood flow within the consolidation (≥2 grades)	Absent or minimal blood flow	Reduced blood flow in late fibrotic areas
Others	Hepatosplenomegaly and renal calcifications suggesting dissemination	Being associated with pleural effusion	–