Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes . There is mild enlargement of the cardiac silhouette , which appears unchanged . The patient is status post CABG with midline sternotomy wires . The mediastinal and hilar contours are unchanged . No definite pulmonary edema . There is bibasilar atelectasis . No large pleural effusion . No pneumothorax . There are no acute osseous abnormalities .
    OUTPUT:
    
Mild cardiomegaly without definite pulmonary edema , as clinically questioned .