Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . The aorta is calcified . The mediastinal and hilar contours are normal . There is no pulmonary edema . On the lateral view , a patchy opacity is noted posteriorly within the right lower lobe , which could represent atelectasis but developing infection is not excluded . No pleural effusion or pneumothorax is identified . There are mild degenerative changes in the thoracic spine .
    OUTPUT:
    
Subtle patchy opacity within the right lower lobe , which could reflect atelectasis though developing infection is not excluded .