Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is normal . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . Streaky left lower lobe opacity is present along with a small left pleural effusion . No pneumothorax is identified . Mild irregularity of the 6 posterior left rib could indicate a nondisplaced fracture .
    OUTPUT:
    
Possible nondisplaced fracture of the left posterior 6th rib . Left lower lobe opacity likely reflects atelectasis with small left pleural effusion . Consider dedicated rib series for further assessment for rib fractures .