Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are again low . A generalized increase in the radiodensity in the lower lungs could be due to edema , less likely to pneumonia , although this is still conceivable if the patient 's clinical picture fits . Bibasilar streaky atelectasis remains . Patient is status post median sternotomy . Cardiomediastinal silhouette and hilar contours are normal .
    OUTPUT:
    
Generalized increase in the radiodensity in the lower lungs could be due to edema , less likely pneumonia .