Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest film ___ at 10 :03 is submitted .
    OUTPUT:
    
Status post median sternotomy with stably enlarged cardiac contour which may reflect cardiomegaly or pericardial effusion . Clinical correlation is advised . Lung volumes are slightly lower with streaky opacities at both lung bases likely reflecting atelectasis . Minimal peribronchial cuffing suggests an element of mild interstitial edema . No pleural effusions . No evidence of pneumothorax .