Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Overall , there has been slight interval progression in overall degree of interstitial pulmonary fibrosis as compared with ___ radiograph . No large effusion or pneumothorax . Difficult to exclude a superimposed subtle pneumonia . The cardiomediastinal silhouette is stable . Bony structures are intact .
    OUTPUT:
    
Interval progression of pulmonary fibrosis compared with ___ .