Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post previous median sternotomy . The heart is mildly enlarged , but there is no evidence of pulmonary edema . Patchy opacities are present in both retrocardiac regions , right greater than left . No pleural effusion or acute skeletal finding .
    OUTPUT:
    
Patchy bibasilar opacities , which may reflect patchy atelectasis , aspiration , or early infectious pneumonia . Followup radiographs may be helpful in this regard .