Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild cardiomegaly . The hilar and mediastinal contours are normal . Lung volumes are increased . There are persistent interstitial reticular opacities within the upper lobes bilaterally , better characterized on prior CT examination . There is no focal consolidation concerning for pneumonia . There are no pleural effusions or pneumothorax . There are degenerative changes along the lower thoracic spine .
    OUTPUT:
    
Upper lobe predominant interstitial lung disease , which could be due to chronic hypersensitivity pneumonitis or ( if the patient is a smoker ) smoking - related interstitial lung disease .