Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged including moderate tortuosity of the descending thoracic aorta . At both lung bases , but greater on the right than left , there are new opacities . These could be seen with atelectasis but infection would also be a possibility to consider . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
New basilar opacities , pneumonia versus atelectasis .