Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been significant improvement in the left - sided effusion with more aerated left lung , particularly at the apex . Left pleural catheter projects at the left lung base . Heterogeneous opacity in the left mid lung corresponds to tumor better seen by CT . The right lung is clear and there is likely a small right pleural effusion . Left PICC terminates at the superior cavoatrial junction .
    OUTPUT:
    
Significant improvement in left pleural effusion , still moderate , with opacification in the left midlung compatible with tumor seen by CT .