Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were obtained . The lungs are hyperlucent with widened AP diameter of the chest , suggesting underlying COPD . There is a large retrocardiac opacity which is slightly increased in size compared with the prior study and likely represents a large hiatal hernia . There is no focal consolidation , effusion , or pneumothorax . No signs of CHF . Heart size appears stable . Mediastinal contour reflects an unfolded thoracic aorta . Bony structures are intact though demineralized .
    OUTPUT:
    
No pneumonia or CHF . Large hiatal hernia . COPD .