Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are similar when compared to the prior study . The trachea is central . The cardiomediastinal contour is unchanged . The previously demonstrated moderate right pleural effusion has decreased , there is however small residual pleural effusion . No left - sided pleural effusion seen . No lobar consolidation or pneumothorax seen . No free air seen under the diaphragm .
    OUTPUT:
    
Small right pleural effusion , decreased when compared to the prior study .