Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are again noted . Patient is rotated to the left . Relative elevation of the left hemidiaphragm is again noted . There is blunting of the left posterior costophrenic angle suggestive of a small effusion . There is possible adjacent atelectasis given retrocardiac opacity noting infection is not excluded . Compression deformities in the lower thoracic spine are only partially visualized .
    OUTPUT:
    
Limited exam . Probable small left - sided effusion . Retrocardiac opacity could be due to atelectasis or potentially infection .