Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged . The lungs appear clear . There are no pleural effusions or pneumothorax . There is blunting of the right posterior costophrenic sulcus , possibly due to scarring versus a very small pleural effusion . Moderate degenerative changes again effect the shoulder .
    OUTPUT:
    
Possible small pleural effusion on the right side for which direct comparison to prior studies is difficult given the lack of a prior available lateral view ; otherwise unremarkable .