Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low inspiratory volumes . ET and NG tube have been removed . Right IJ central line with tip at cavoatrial junction . Mediastinal drain and left chest tube again noted . No pneumothorax is detected . Mild prominence of the cardiomediastinal is unchanged . Sternotomy wires again noted . Patchy opacity at the left lung base is similar prior , though there is new partial obscuration of left hemidiaphragm . Platelike atelectasis in the right mid zone is also new . Minimal blunting of the right costophrenic angle is grossly unchanged . No overt CHF . Upper zone redistribution has improved .
    OUTPUT:
    
Mild patchy opacity left base is increased in terms of partial obscuration left hemidiaphragm . Improvement in upper zone redistribution . No overt CHF . No pneumothorax detected .