Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared with prior radiographs on ___ , again seen is a retrocardiac opacity . No pleural effusion or pneumothorax is seen . There is no edema . The cardiac and mediastinal silhouettes are unchanged . Again seen is widespread multifocal osteoblastic disease .
    OUTPUT:
    
1 . Left lower lobe pneumonia . 2 . No change in widespread , multifocal osteoblastic disease .