Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Severe emphysema again noted . A linear density is unchanged in the left mid lung is compatible with scarring . There is no focal consolidation , large effusion or pneumothorax . The cardiomediastinal silhouette is stable . No acute bony abnormality .
    OUTPUT:
    
Severe emphysema without superimposed acute process .