Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Retrocardiac opacities compatible with known hiatal hernia . There is mild left basal atelectasis . Otherwise lungs are clear . Cardiomediastinal silhouette is normal . No large effusion or pneumothorax . Bony structures appear intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Hiatal hernia . Mild left basal atelectasis . No convincing evidence for pneumonia .