Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Mediastinal and hilar contours are unremarkable . The pulmonary vasculature is normal . Patchy opacities are noted in the lung bases , potentially atelectasis and scarring , without focal consolidation . No pleural effusion or pneumothorax is seen . No acute osseous abnormalities detected . Moderate multilevel degenerative changes are seen within the thoracic spine .
    OUTPUT:
    
Patchy bibasilar opacities likely reflect atelectasis and scarring , without focal consolidation . No pulmonary edema .