Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to chest radiograph from 1 day prior , mild pulmonary vascular congestion has improved . Retrocardiac opacity and small left - sided pleural effusion have marginally improved . Moderate cardiomegaly persists . No pneumothorax .
    OUTPUT:
    
Interval improvement in mild pulmonary vascular congestion . Retrocardiac opacity and small left - sided pleural effusion have marginally improved .