Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Moderate enlargement of the cardiac silhouette is unchanged . The aorta remains tortuous . The mediastinal and hilar contours are similar without pulmonary vascular congestion . Linear and streaky opacities in the lung bases are somewhat improved from the previous exam , likely reflective of atelectasis . No focal consolidation , pleural effusion or pneumothorax is demonstrated .
    OUTPUT:
    
Improving bibasilar atelectasis .