Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . Heart size and cardiomediastinal contours are normal . Retrocardiac density is most compatible with a hiatal hernia . Right lung base opacity is small and could represent pneumonia or atelectasis . No pleural effusion or pneumothorax .
    OUTPUT:
    
1 . Right lung base opacity , consistent with pneumonia or atelectasis . 2 . Retrocardiac density , most compatible with a hiatal hernia .