Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes . Vascular engorgement , but no frank pulmonary edema . There is a moderate - sized left pleural effusion . Stable enlargement of the cardiomediastinal silhouette . No focal consolidations to suggest pneumonia . No pneumothorax . No evidence of rib fracture .
    OUTPUT:
    
Moderate - sized left pleural effusion , which may be traumatic in nature . No evidence of associated rib fracture .