Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette size is normal . The mediastinal and hilar contours are unremarkable . The pulmonary vasculature is normal . No focal consolidation , pleural effusion or pneumothorax is identified . There are mild degenerative changes within the imaged thoracic spine . Irregularity of the left posterior lateral eighth rib is concerning for a fracture .
    OUTPUT:
    
No acute cardiopulmonary abnormality . Irregularity of the left ___ posterolateral rib is concerning for a fracture .