Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . The lungs appear stable with slight coarsening of interstitial markings , which could reflect underlying fibrosis or emphysema . No focal consolidation to suggest pneumonia . Heart remains mildly enlarged . Mediastinal contour is stable . No pneumothorax or pleural effusion . Bony structures appear intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
No acute intrathoracic process . Probable underlying interstitial lung disease .