Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is normal . The aorta is mildly tortuous . The mediastinal and hilar contours are normal . Pulmonary vasculature is normal . No focal consolidation , pleural effusion or pneumothorax is present . Linear opacity in the left lower lobe likely reflects subsegmental atelectasis or scarring . There are mild degenerative changes in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .