Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable view of the chest . Low lung volumes are again noted . Chronic changes compatible with patients pulmonary fibrosis are noted . More severely affected areas seen at the bases , left greater than right . Cardiomediastinal silhouette is stable . No acute osseous abnormalities identified .
    OUTPUT:
    
Findings again compatible with patient 's known pulmonary fibrosis without definite superimposed acute process , noting that subtle change would be difficult to detect based on a portable film .