Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Allowing for positioning , the retrocardiac opacification and the opacification of the right lower lung are unchanged compared to the prior study ___ . The left upper lobe postsurgical changes continue to improve . There is no pneumothorax or pulmonary edema . The cardiomediastinal silhouette is within normal limits .
    OUTPUT:
    
Unchanged appearance of bilateral lower lobe opacification .