Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size appears mildly enlarged but similar . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . Minimal patchy opacities are noted in the lung bases . No focal consolidation , pleural effusion or pneumothorax is evident . There are mild degenerative changes in the upper lumbar spine . No acute osseous abnormality is visualized .
    OUTPUT:
    
Minimal bibasilar patchy opacities , likely atelectasis .