Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: On the prior study , hazy and nodular opacities have markedly improved , although there is persistent but decreased posterior right basilar opacification with blunting of the right costophrenic sulcus and so probably a pleural effusion . There is no definite pleural effusion on the left . The heart size appears reduced .
    OUTPUT:
    
Marked interval improvement in multifocal lung opacities . Although a superimposed acute process in the right lower lobe is difficult to exclude , the latter is probably a more chronic appearance .