Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear stable . The right hemidiaphragm is mild to moderately elevated , probably with a small subpulmonic effusion but likely decreased substantially . There is persistent patchy right posterior basilar opacity overlying the diaphragm although atelectasis may be suspected in the early post-operative course as the likely cause .
    OUTPUT:
    
Persistent right posterior basilar opacity , probably compatible with atelectasis , with persistent small decreased pleural effusion . Pneumonia at the right lung base is not excluded however although post-operative volume loss seems more likely as the cause .