Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . A prominent retrocardiac opacity could represent a large hiatal hernia . No convincing sign of pneumonia or CHF . The heart size appears prominent though this is likely secondary to AP technique . No large effusion or pneumothorax . Bony structures appear intact .
    OUTPUT:
    
Large hiatal hernia . Otherwise unremarkable .