Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear stable . A small right apical pneumothorax appears unchanged . A small right - sided pleural effusion is not well assessed , being largely subpulmonic . Streaky right lower lung opacification suggests atelectasis , similar to findings on the recent prior chest CT . However , more diffuse opacification has improved since the prior radiographs . Non-displaced fractures of the right posterior fourth and fifth ribs are visible .
    OUTPUT:
    
Improvement in vague widespread opacification , probably improving pulmonary edema . Stable small right - sided pneumothorax . Persistent opacity at the right lung base , probably compatible with atelectasis , although aspiration is not excluded as a possible alternative etiology .