Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is mildly enlarged . The aorta is tortuous . The mediastinal contours otherwise unchanged . Pulmonary vascularity is normal and the hila are unremarkable . Lung volumes are low with bibasilar atelectasis . No focal consolidation , pleural effusion or pneumothorax is clearly noted . Known diffuse osseous metastatic disease is better visualized on the previous CT .
    OUTPUT:
    
Mild bibasilar atelectasis .