Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size remains top normal . The mediastinal and hilar contours are unchanged , with calcification of the aortic knob . There continues to be minimal patchy opacities in the lung bases which may reflect atelectasis . No pulmonary vascular engorgement is definitively noted . Small bilateral pleural effusions may be present , but no pneumothorax is identified .
    OUTPUT:
    
Minimal atelectasis in the lung bases with possible small pleural effusions . No evidence for pulmonary edema .