Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is borderline enlarged , unchanged . The aorta is tortuous . Mediastinal and hilar contours are similar . Crowding of the bronchovascular structures is demonstrated . Patchy opacity in the left lung base likely reflects an area of atelectasis . No pleural effusion or pneumothorax is present . No acute osseous abnormalities are identified .
    OUTPUT:
    
Low lung volumes . Left basilar patchy opacity , likely atelectasis .