Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . A large retrocardiac opacity is consistent with known large hiatal hernia . Lung volumes are low limiting assessment . There is left basal platelike atelectasis . No convincing evidence for pneumonia or pneumothorax . No large effusion is seen . Cardiomediastinal silhouette appears grossly within normal limits . Bony structures are intact .
    OUTPUT:
    
Large hiatal hernia . Otherwise unremarkable .