Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low with persistent bibasilar opacities , not well evaluated on this single view ; there is improved aeration at the left lung base compared to prior . No large pleural effusion or pneumothorax is detected . Heart and mediastinal contours are stable ; heart size is exaggerated by low lung volumes . Lower thoracic vertebroplasty again noted .
    OUTPUT:
    
Mild bibasilar opacities with interval improvement in aeration at the left lung base .