Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bibasilar linear opacities are consistent with platelike atelectasis . Otherwise the lungs are clear . No focal consolidation , effusion , edema , or pneumothorax . The heart size is normal . The thoracic aorta is slightly tortuous . Aortic knob calcifications are mild . Segmental fractures of the left posterior ___th rib fractures appear chronic and healed .
    OUTPUT:
    
1 . No pneumonia . 2 . Platelike atelectasis in the lower lungs . 3 . Chronic left segmental rib deformities involving the fifth through eighth ribs .