Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Mediastinal and hilar contours are unchanged with a moderate size hiatal hernia again noted . Pulmonary vasculature is normal . A small right pleural effusion is decreased in size from the prior examination . Lungs are otherwise clear . No pneumothorax is identified .
    OUTPUT:
    
Trace right pleural effusion , decreased from the prior study .