Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Increased interstitial markings seen the lung bases , left greater than right . Superiorly , the lungs demonstrate coarse interstitial markings but without consolidation . Cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities .
    OUTPUT:
    
Coarsened interstitial marking suggesting chronic underlying interstitial process . More confluent opacities at the lung bases , left greater than right . While these could be chronic in nature , superimposed infection would be possible