Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is top normal , unchanged . Mediastinal and hilar contours are similar . Pulmonary vasculature is normal . Atelectasis is demonstrated in the lung bases without focal consolidation . No pleural effusion or pneumothorax is present . Multilevel degenerative changes are present within the thoracic spine .
    OUTPUT:
    
Minimal bibasilar atelectasis without focal consolidation