Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is mildly enlarged . Mediastinal and hilar contours are within normal limits . Pulmonary vasculature is normal . Subsegmental atelectasis is noted in the left lung base . Lungs are otherwise clear without focal consolidation . No pleural effusion or pneumothorax is present . Mild degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .