Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low , similar to prior . Linear opacity in the left base is unchanged and consistent with atelectasis or scarring . No focal consolidation , pleural effusion , or pneumothorax . Heart size and cardiomediastinal contours are normal .
    OUTPUT:
    
No focal consolidation . Unchanged left base atelectasis or scarring .