Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The size of the left pleural effusion has decreased , but remains moderate in size . The lungs are otherwise clear . The pulmonary vasculature is normal . The cardiomediastinal silhouette is stable . There is no pneumothorax .
    OUTPUT:
    
Moderate - sized left pleural effusion , which has decreased in size compared to prior .