Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single frontal image of the chest demonstrates bibasilar densities , unchanged since previous imaging . The left - sided pleural effusion has improved slightly . There is no right - sided pleural effusion . There is no upper zone distribution . There is no discrete evidence of pneumonia , but bibasilar densities could be contributing to the patient 's clinical picture . Cardiomegaly is again seen .
    OUTPUT:
    
Essentially unchanged chest radiograph with persistent bibasilar opacities and left pleural effusion .