Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy and CABG . Moderate cardiomegaly is re - demonstrated . The mediastinal contour is unchanged with tortuosity of the thoracic aorta again noted . Mild pulmonary vascular congestion appears slightly improved compared to the prior study . There appears to be a small left pleural effusion with bibasilar atelectasis . No pneumothorax is identified . There are no acute osseous abnormalities detected . A right PICC tip terminates at the SVC / right atrial junction .
    OUTPUT:
    
Improving mild pulmonary vascular congestion with trace left pleural effusion . Bibasilar atelectasis .