Relationship between neonatal respiratory distress syndrome pulmonary ultrasonography and respiratory distress score, oxygenation index, and chest radiography grading

Table 2 X-ray grading and imaging manifestations

X-ray grading	X-ray imaging manifestations
0	No image changes
I	The transparency of both lung fields is generally reduced, with evenly scattered small particles and reticular shadows visible
II	Except for the aggravation of grade I changes, bronchial inflation sign can be seen, extending to the middle and outer zones of the lung field
III	The lesion worsens, the transparency of the lung field decreases further, and the cardiac and diaphragmatic margins appear blurry
IV	The entire lung field appears as a white lung, with more pronounced bronchial inflation signs resembling bald branches