Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size remains mildly enlarged . The aorta is diffusely calcified . Mediastinal and hilar contours are unchanged . The pulmonary vasculature is not engorged . Minimal patchy bibasilar airspace opacities are similar on the right , and slightly worse on the left , and may reflect areas of atelectasis , though infection or aspiration in the left lung base is not excluded . No pleural effusion or pneumothorax is seen . There is no focal consolidation . Moderate multilevel degenerative changes are noted in the thoracic spine . No subdiaphragmatic free air is present .
    OUTPUT:
    
Patchy bibasilar airspace opacities , slightly worse on the left compared to the prior study , which may reflect atelectasis though infection or aspiration can not be excluded .