Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are flattened diaphragms suggestive of probable background COPD . However , on the frontal view , inspiratory volumes are relatively low . There is bibasilar atelectasis . No air bronchograms or confluent opacity to suggest focal consolidation . No CHF . Minimal blunting of left costophrenic angle . No gross effusion . Allowing for low lung volumes , the cardiomediastinal silhouette is likely unchanged .
    OUTPUT:
    
Probable bibasilar atelectasis , new compared with ___ . An early pneumonic infiltrate is considered much less likely . Suspect background COPD .