Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Dual lead left chest wall pacing device is again seen . Bibasilar opacities are most likely atelectasis . Superiorly , the lungs are clear . The cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities identified , chronic left posterior rib fractures are noted .
    OUTPUT:
    
No definite acute cardiopulmonary process .