Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Chest PA and lateral radiograph demonstrates unremarkable mediastinal and hilar contours . There is a moderate to marked enlargement of the cardiac silhouette . Pacemaker leads positioned in the right atrium and right ventricle . Bilateral low lung volumes . Obscuration of the left hemidiaphragm in combination with retrocardiac opacity may suggest atelectasis in combination with pleural effusion , however , opacification persists on lateral views raising concern for pneumonia . Streaky atelectasis identified in the right lower lung . No pneumomediastinum evident . Extensive multilevel degenerative changes with anterior osteophyte formation as well as degenerative changes at the right glenohumeral joint .
    OUTPUT:
    
1 . Retrocardiac opacity may represent combination of atelectasis and effusion ; however , underlying consolidation due to aspiration or pneumonia may be present and is of concern . 2 . No pneumomediastinum . 3 . Moderate to marked enlargement of the cardiac silhouette without prior for comparison , may be due to cardiomyopathy and / or pericardial effusion .