Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable chest radiograph . Extensive bilateral pulmonary parenchymal opacifications are evident across multiple prior radiographs dating back to ___ ; however , opacifications appear slightly increased on today 's exam , possibly reflecting worsened background pulmonary edema , though superimposed infectious process is not definitively excluded . Stable elevation of right hemidiaphragm . Blunting of the right costophrenic angle appears unchanged , but can not exclude a small right pleural effusion . Pacemaker leads and sternotomy sutures are intact . No osseous lesion evident .
    OUTPUT:
    
Persistent but increasingly prominent bilateral pulmonary opacities may reflect chronic disease superimposed on background edema , though can not exclude superimposed infectious process . Possible small right pleural effusion .