Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size remains top normal . The mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . Linear and patchy atelectasis is demonstrated in both lung bases . There is mild blunting of the left costophrenic angle , as seen on the previous examination , which likely reflects pleural thickening . No focal consolidation , pleural effusion or pneumothorax is present . No acute osseous abnormality is seen .
    OUTPUT:
    
Bibasilar atelectasis . No evidence for pulmonary edema .