Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette size is normal . The mediastinal and hilar contours are unchanged , with mild calcification of the aortic knob again noted . The pulmonary vasculature is not engorged . Patchy and linear opacities in the lung bases appear progressed in the interval . No pleural effusion or pneumothorax is demonstrated . Vertebroplasty changes are noted within the mid and lower thoracic spine . Multilevel degenerative changes are present in the thoracic spine .
    OUTPUT:
    
Worsening bibasilar airspace opacities , likely reflective of atelectasis , but aspiration can not be completely excluded .