Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A heterogeneous opacity in the left mid lung could represent a focus of infection . There is a small left pleural effusion . The lungs are otherwise clear . Cardiomediastinal silhouette is normal . No displaced rib fracture .
    OUTPUT:
    
Heterogeneous left mid lung opacity may represent developing infection . Small left pleural effusion . No displaced rib fracture .