Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest . There has been interval substantial improvement in the bibasilar opacities , although they are not entirely cleared . No focal consolidation is seen . The heart , hilar and mediastinal contours are normal . No pleural abnormality is seen .
    OUTPUT:
    
Substantial interval improvement in bilateral opacities , although not entirely cleared .