Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy , CABG , and mitral valve replacement . Heart size is normal . Mediastinal and hilar contours are unchanged . Mild pulmonary vascular congestion appears slightly improved in the interval . There is atelectasis noted at the lung bases without focal consolidation . No pleural effusion or pneumothorax is detected .
    OUTPUT:
    
Interval improvement in mild pulmonary vascular congestion .