Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . Lung volumes are lower than on the prior study . There is mild bibasilar atelectasis . No focal consolidation , pleural effusion or pneumothorax . The cardiac silhouette is top normal in size . Mediastinal silhouette and hilar contours are stable allowing for lower lung volumes . Calcifications are seen along the course of the thoracic aorta . Mediastinal post - surgical changes including coronary stents and intact median sternotomy wires are unchanged .
    OUTPUT:
    
No pneumonia , edema or effusion . Mild bibasilar atelectasis .