Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs demonstrate clear , well - expanded lungs without pleural effusion or pneumothorax . There are surgical changes of median sternotomy and CABG . The cardiac silhouette is top normal in size , the mediastinal contours are normal . The pulmonary vasculature is normal .
    OUTPUT:
    
Mild cardiomegaly status post CABG , without acute chest abnormality .