Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low . The mediastinal , cardiac and hilar contours appear unchanged . There is mild elevation of the right posterior diaphragm . Atelectasis has improved since the prior examination , and the lungs appear clear . There is no pleural effusion or pneumothorax . Surgical clips project about the undersurface of the medial left hemidiaphragm . Bony structures are unremarkable .
    OUTPUT:
    
No evidence of acute disease .