Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are relatively low . Small right pleural effusion has decreased in size since the prior study , as has overlying right middle and lower lobe atelectasis . Relative lucency projecting over the lateral right lower hemi thorax may be artifactual versus less likely loculated pneumothorax . No left pleural effusion is seen . The left lung is grossly clear . Patient is status post median sternotomy and CABG . Cardiac and mediastinal silhouette are stable .
    OUTPUT:
    
Small right pleural effusion has decreased since the prior study . Right middle and lower lobes atelectasis has also significantly decreased in the interval . Relative ovoid lucency projecting over the lateral right lower hemi thorax is felt to most likely be artifactual versus less likely loculated pneumothorax .