Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is mildly enlarged . An aortic valve replacement is visualized partcularly on the lateral view . The mediastinal silhouette and hilar contours are unremarkable . Mild bibasilar atelectasis is noted . The lungs are otherwise clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No acute intrathoracic process .