Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views the chest were provided . Mild basal atelectasis noted . Subtle gas - filled retrocardiac opacity is most compatible with a small hiatal hernia . No large effusion or pneumothorax . Heart is top - normal in size . Mediastinal contour is stable and normal . Mild to moderate atherosclerotic calcification of the aorta noted . Imaged osseous structures are intact .
    OUTPUT:
    
As above . No convincing evidence for pneumonia or edema .