Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A frontal upright view of the chest was obtained portably . Lung volumes are slightly low resulting in bronchovascular crowding . Mild bibasilar atelectasis is noted . There is no focal consolidation , pleural effusion or pneumothorax . Mild enlargement of the cardiac silhouette is unchanged . Mediastinal silhouette is normal and unchanged since ___ .
    OUTPUT:
    
Normal mediastinal silhouette . No pneumonia , edema or effusion .