Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is asymmetric left basilar opacity . Superiorly , the lungs are clear where not obscured by the left chest wall single lead pacing device . The cardiac silhouette is moderately enlarged as on prior . Hypertrophic changes are noted in the spine .
    OUTPUT:
    
Left basilar opacity , potentially atelectasis noting infection is not excluded .