Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest demonstrate normal cardiomediastinal silhouette . The lungs appear hyperexpanded , in keeping with known emphysema . Previously seen left lower lobe opacity has resolved on the frontal view but may persist on lateral view obscuring the posterior costophrenic angle , which could represent a component of residual infection and / or atelectasis . There is trace basilar atelectasis on the right . There is no large effusion . Eventration is seen on the right , unchanged .
    OUTPUT:
    
Bibasilar dependent atelectasis . Persistent probable left lower lobe posterior opacity which could represent atelectasis or a component of residual infection , to be clinically correlated . Followup after treatment recommending to document resolution .