Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is dense retrocardiac opacity compatible with volume loss / infiltrate / effusion . There is improved aeration left upper lobe . There continues to be some hazy alveolar infiltrate in the right lower lobe . The heart is moderately enlarged , similar to prior . NG tube tip is in the stomach . There is some residual contrast in the colon .
    OUTPUT:
    
Improved aeration in the left upper lobe with worsened appearance of the left lower and right lower lobes .