Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared with ___ at 20 :32 p .m . , there has been marked improvement in the appearance of the left lung . There is now a small - to - moderate effusion at the left base , with underlying collapse and / or consolidation , but the mid and upper portions of the left lung are now visible and well aerated . No CHF . Right base atelectasis is slightly more pronounced . No right effusion .
    OUTPUT:
    
Marked improvement in the appearance of the left lung .