Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal and hilar contours are within normal limits . There is mild calcification of the aortic knob . Linear opacity seen in the left upper lung field , right lung base and lingula likely represents atelectasis or scarring . Otherwise , no focal consolidation , pleural effusion or pneumothorax is identified .
    OUTPUT:
    
No evidence of an acute cardiopulmonary process .