Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is at the upper limits of normal size . The mediastinal and hilar contours appear within normal limits . There is no pleural effusion or pneumothorax . Patchy opacity in the lingula suggests minor atelectasis or scarring . Otherwise , the lungs appear clear . The bony structures are unremarkable .
    OUTPUT:
    
Patchy left basilar opacity most suggestive of minor atelectasis or scarring . No definite evidence for acute disease .