Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy and aortic valve replacement . Moderate cardiomegaly remains unchanged . Mediastinal contours are similar . There is mild pulmonary edema , with patchy atelectasis noted in the lung bases . A small left pleural effusion appears not substantially changed in the interval . Patchy opacities are noted in the lung bases . No pneumothorax is detected . No acute osseous abnormality is visualized .
    OUTPUT:
    
Continued moderate cardiomegaly and mild pulmonary edema . Small left pleural effusion , not substantially changed in the interval . Patchy bibasilar airspace opacities likely reflect atelectasis however infection can not be excluded .