Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post coronary artery bypass graft surgery . The cardiac , mediastinal and hilar contours are unremarkable aside from a double contour appearance to the left cardiac border which may indicate the presence of a large left atrium . There is a small pleural effusion on the right and patchy opacification at the right lung base , probably atelectasis . Prominent indistinct pulmonary vasculature and mild interstitial abnormality are suggestive of mild pulmonary edema although without prior studies , it is difficult to assess for chronicity of interstitial changes in the lower lungs .
    OUTPUT:
    
Findings suggest mild pulmonary edema . Small right - sided pleural effusion . Question regarding possibility of enlarged left atrium .